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rstrucks
08-03-2010, 03:39 PM
Alright guys. Here's the topic, lets talk about it. Try to stay focused on tech and past experience on what works and what doesn't. I thought about going with a suspension thread in general (to include the rear) but I thought there is plenty of material to cover on just the front. So lets kick around some ideas about radius arms, three links, four links w/ panhard bar and triangulated 4 links. I know there is a seperate discussion about what exactly constitutes a "link" and if a panhard/track bar counts towards the total, but for the sake of simplicity lets assume that a panhard/track bar does not count. ;)

Post up pics of what you did, how you did it, what you like, what you don't, why you "upgraded", the geometry, etc.....

ATL ZJ
08-03-2010, 03:56 PM
thanks for taking this over Ryan. we're off to a good start on the panhard classification ;) :o

Caster takes precedence over pinion angle

Tri 4 link > 3 link > claytons "radius" arm > ford radius arm > shortarm > stock garbage

front axle in front of crank pulley for maximum performance and best weight dist.

shoot for 7-8"+ of vertical separation

downtowncb
08-03-2010, 04:32 PM
... 3 link > claytons "radius" arm ...

Along these lines, has anyone converted a Clayton radius arm to a 3 link? It would be a tight squeeze but I think you might be able to fit an upper on the driver's side. Just been rolling around my head for a while.

Why exactly is a 3 link better than a radius arm? I've heard because it unloads on steep stuff but why? If I were to route my winch for suck down duty on my Claytons setup would that be about as good as a 3 link?

From my personal battle to eliminate bump steer and potential sources of death wobble. When designing a front end from scratch, make the track bar (from bolt to bolt) and the drag link (from center of TRE to center of TRE) the same length and as close to parallel as possible.

This took some revision to get perfect.

http://i34.photobucket.com/albums/d133/dtcb70/Motor%20Swap/IMG_0878.jpg

AgitatedPancake
08-03-2010, 04:52 PM
I've been pondering the same question about claytons, and I don't see why not. I'll most likely be doing a 3 link when I do the 609.

There is one catch though, and I've pondered it for a while...as you know with a 3 link it is recommended to have hard joints (such as heims or johnny joints) on all ends of both lowers and the upper, to avoid the looseness inherent with bushings, as it's the most apparent on a 3 link setup. Do you think you can successfully/reliably get away with possibly doing poly bushings on one end of both the lowers? I'm talking like replacing the clayton LCA bushings with poly's and use the lowers for the 3 link.

I mean I know this setup would "work", but how would it feel on the road? Would the polys be firm enough to hold up to having a single upper link, especially if the upper has hard joints on both ends?

jfowlzj95
08-03-2010, 05:02 PM
There is one catch though, and I've pondered it for a while...as you know with a 3 link it is recommended to have hard joints (such as heims or johnny joints) on all ends of both lowers and the upper, to avoid the looseness inherent with bushings, as it's the most apparent on a 3 link setup. Do you think you can successfully/reliably get away with possibly doing poly bushings on one end of both the lowers? I'm talking like replacing the clayton LCA bushings with poly's and use the lowers for the 3 link.

Been thinking this same thing, as I'm running Ballistic's poly joints on the front lowers. Was thinking about just going ahead and keeping the lowers as is and using heims on the upper.

OverkillZJ
08-03-2010, 05:19 PM
FWIW: I tried a single upper link with a large grade 8 bolt and poly bushings - it worked for awhile but I chewed up bushings. I think heims or johny's (I know they're kind of poly) would work much better.

Obviously some of you know about the first fiasco where it didn't work when I accidentally put a grade 5 bult in the single upper, and it broke.

rstrucks
08-03-2010, 06:02 PM
Along these lines, has anyone converted a Clayton radius arm to a 3 link? It would be a tight squeeze but I think you might be able to fit an upper on the driver's side. Just been rolling around my head for a while.

Why exactly is a 3 link better than a radius arm? I've heard because it unloads on steep stuff but why? If I were to route my winch for suck down duty on my Claytons setup would that be about as good as a 3 link?



I will soon be converting my Rusty's radius arms to a 3 link. I plan on installing forged flex joints on the axle ends to replace the OE style rubber bushings and removing the arm bracket for the upper links. I then plan on building a new third link, again using flex joints, and mounting it next to the t-case linkage on the driver side. I may have to modify the floor pan to do so though. The other end will mount to the top of the diff housing.

The 3 link is better than a radius arm set up because of less binding. When a radius arm moves through it's arc of travel the axle will obviously follow that arc. The problem comes in when the other side is staying put or articulating in the opposite direction. Because both upper arms are fixed the bushings have to deflect to absorb some of the difference or you will twist off a mount as the arms in effect try to twist the axle tube. That is why my axle end lower arm bushings are shot. I haven't replaced them either because I figure the bushings need this and I have plans on replacing the radius arms anyway. As far as the unloading goes, I haven't really noticed that too much. I have seen a number of radius arm suspensions axle hop a good bit.

Cody
08-03-2010, 06:59 PM
I've run lengthened and jointed radius arms on the front of my last 3 ZJs. The buggy was triangulated radius with 1.25" heims at the frame, the 93 was Clayton/RE style "Y" radius arms with Tera joints at the frame, and my current one is lengthened ford arms with Tera joints at the frame.

All three used triangulated rear suspensions, and the two full bodied ZJ's used identical rear suspensions and even though the execution on the radius arms was different ("Y" arm style vs. true radius) they both behaved very similarly.

All that being said, whether you use radius, 3 link, 4 link or anything else, I've found the thing that makes the biggest difference in how the rig can climb is a center limiting strap. I can't overstate how much of a noticeable difference this simple modification makes to a front long arm suspension.

Weld a tab to the center of the axle, and route the top to the motor mount. Buy a strp that will leave about an inch of slack at ride height. Motor mount may not sound ideal, but I haven't had a problem in 8 years of doing it this way.

OverkillZJ
08-03-2010, 07:15 PM
X2 on the center strap - made a world of difference on my junk.

downtowncb
08-03-2010, 08:06 PM
All that being said, whether you use radius, 3 link, 4 link or anything else, I've found the thing that makes the biggest difference in how the rig can climb is a center limiting strap. I can't overstate how much of a noticeable difference this simple modification makes to a front long arm suspension.

Ok cool, so it would seem that using my winch as a suck down winch would accomplish this effect while not loosing down travel while going fast.

Cody
08-03-2010, 08:15 PM
Ok cool, so it would seem that using my winch as a suck down winch would accomplish this effect while not loosing down travel while going fast.

It sure would, but I found it far easier to weld a tab and play with 2 bolts than it was to safely route a winch cable around my bumper and through the steering in my front end. Obviously if you start from scratch you can engineer the solution.

I drive plenty fast, and quite honestly 90% of my offroad mileage is in the high-range, back-road-bombing variety, and my front strap is 100% transparent to me.

I will note, that I've had one for so long I may not know what it feels like without it.

faststang1
08-03-2010, 09:53 PM
I been thinking of a 3-link for a while to,but then again my claytons works awsome.but I want to try a 3 link.I have talked to clayton and there going to build a 3 link upgrade for the ZJ.there going to use a 2.5 JJ with a 9/16 bolt at the axle end and at the frame.

IndyZJ
08-04-2010, 01:27 AM
I've been pondering the same question about claytons, and I don't see why not. I'll most likely be doing a 3 link when I do the 609.

There is one catch though, and I've pondered it for a while...as you know with a 3 link it is recommended to have hard joints (such as heims or johnny joints) on all ends of both lowers and the upper, to avoid the looseness inherent with bushings, as it's the most apparent on a 3 link setup. Do you think you can successfully/reliably get away with possibly doing poly bushings on one end of both the lowers? I'm talking like replacing the clayton LCA bushings with poly's and use the lowers for the 3 link.

I mean I know this setup would "work", but how would it feel on the road? Would the polys be firm enough to hold up to having a single upper link, especially if the upper has hard joints on both ends?

I've been wondering about the same thing. I've always read that you need all "hard" joints in a 3 link (w/ panhard) because any give would lead to unwanted axle movement, specifically rotation. The IRO kit with a single radius arm has made me wonder though, because it essentially has the same kind of attachment to the axle. It uses all rubber mounts at the axle and I haven't heard any complaints of bad road manners yet. I have driven an old Ford with a wristed radius arm setup that is essentially the same idea, and it felt very sloppy compared to a normal radius arm or link setup. The only thing I can figure out is that the IRO kit has enough seperation at the axle to make a difference and the solid radius arm must help to a degree, too. That or nobody with the IRO kit knows any better :flipoff2:

When I get to the ZJ, I really want to go to a 3 link, but I may have to go with a mid-arm setup because I'm not going to run more than 3" of lift and I really don't want to run radius arms because of the bushing-killing binding and potential unloading. Unless I run a very bent upper or severely hack the floor, I don't think I'll be able to fit a true "long arm" 3 link. With so little lift, I'm thinking I wouldn't have the anti squat/dive issues associated with radius arms, but I'd rather go with a 3 link if I can make it fit. I may end up giving in and going with a single-sided radius arm design similar to IROs, but a little beefier and with hard joints instead of the goofy caster adjuster they use and factory bushings. It'll come down to whatever I can fit without a ridiculous amount of work. Either way it will get a center limit strap like Cody suggested.

As far as 3 link setup goes, I'd go with what ATL posted and just run as much seperation as you can make fit at the chassis side (assuming we're talking about full-body ZJs/WJs). The best results seem to come from making the upper link as close to horizontal as possible.

Has anybody run this? It looks to be the pre-made solution that uses the biggest bolt (14mm) in the D30 cast-in upper mount. Genright usually only sells high-quality stuff but the RK name makes me wonder.
http://www.genright.com/ProductInfo.aspx?productid=SUP2100
The other option I know of is a Johnny joint that uses a 1/2" bolt and presses in.

FortCollinsZJ
08-04-2010, 01:41 AM
I had been wanting to upgrade from the radius arm Claytons, to a three, or fourlink, and decided to go the way of a fourlink, my uppers both have a 15* bend in them (passenger side needed to clear the exhaust) I had to trim the pinch on the inside of the frame rails on both sides, and weld the "frame" back closed. I also used a holeswaw to cut a clearence in both frame rails to insert a piece of tube to act as bolt pass throughs for the frame side upper bolts. After getting it all in and testing the flex, it is outstanding, with no bind in any normal amount of travel, tested at 14" droop (shocks disco'd), and full bump. The pinion angles are acceptable through the entire travel range.

Any brake steer that I had before is gone completely. It handles ALOT better on and offroad than the radius arm setup ever did. I have had one shake down run on a rocky trail at speed, and it was very predictable and better described as "tight". I have yet to test it in a rock crawling scenario, that will happen this weekend.

I chose the four link over the three for the simple reason that I didn't want to have to trust a single 1/2" bolt on a single upper. And for the fact that a three link is more prone towards brake steering than an four link.

I will have to get some pictures soon, I am very pleased with the way it all came out.

jfowlzj95
08-04-2010, 01:44 AM
Here's a question for those who want to convert Clayton's to a 3-link.

At the body/frame, would you mount the upper on the center cross-member piece? Think it would be a strong enough spot to mount an upper to with 4 grade 8 bolts and the transmission holding it into place. Or would you mount it at a more 'fixed' spot, like the inner frame rail or maybe even on top of the outer cross-member piece where the lower mounts? If there is enough room there, would most likely consider a heim in this situation.

FortCollinsZJ
08-04-2010, 01:52 AM
Mount it to the "fixed spot" Not on the removable section. That would be a PITA everytime you want to remove the center section. The center section also has no room, the driveshaft hovers right over the spot you would be placing the link mount. One glance under the jeep and it's worth a thousand words.

downtowncb
08-04-2010, 02:17 AM
I had been wanting to upgrade from the radius arm Claytons, to a three, or fourlink, and decided to go the way of a fourlink, my uppers both have a 15* bend in them (passenger side needed to clear the exhaust) I had to trim the pinch on the inside of the frame rails on both sides, and weld the "frame" back closed. I also used a holeswaw to cut a clearence in both frame rails to insert a piece of tube to act as bolt pass throughs for the frame side upper bolts. After getting it all in and testing the flex, it is outstanding, with no bind in any normal amount of travel, tested at 14" droop (shocks disco'd), and full bump. The pinion angles are acceptable through the entire travel range. ...

Get some pictures up ASAP please. I remember when you were posting up CAD drawings of your ideas a while back, or at least I think it was you. Glad to hear you made it into a reality. Why do you say a 3-link tends to brake steer?

jfowlzj95
08-04-2010, 02:25 AM
Mount it to the "fixed spot" Not on the removable section. That would be a PITA everytime you want to remove the center section.

Agreed it would be a PITA, but for just a single upper I don't think it would be too bad. There are actually some designs where they mount the upper and lowers to the transmission cross-member. :rolleyes:


The center section also has no room, the driveshaft hovers right over the spot you would be placing the link mount. One glance under the jeep and it's worth a thousand words.

What if you were to run a pass drop axle and tcase? I'm planning on going this route, looks like it would free up a ton of space to mount that upper on the drivers side.

I am in favor of mounting the upper on the inner frame rail, just curious if that center piece would be strong enough for the single upper the way it mounts to the other pieces, or would it just be more prone to failure. We've all seen what happened to Matt's buggy when that bolt to his upper failed.

x2 on getting pics of yours ASAP. After seeing your planning on it, it's become my back up plan if I decide to ditch the 3-link.

FortCollinsZJ
08-04-2010, 03:39 AM
Here are some bad cell phone pictures I just snapped. These are pretty much all passenger side pictures. Packed pretty tight in there, but it all fits no problem.

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/89da5497.jpg

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/7150b6e7.jpg

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/86a0632a.jpg

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/e7ccb76a.jpg

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/49004944.jpg

http://i203.photobucket.com/albums/aa231/NEILZJ/Four%20link%20front/2e68796b.jpg


DownTownCB, I took off a single upper off of my radus arm setup for a day to see how it felt, under HEAVY braking, the axle would pivot on the soft rubber on the axle end of the lower CA's and would cause a bit of steering slop and a pull to the right. I have heard of it being similar with a three link with any poly or rubber in the setup. I just wanted a setup that would eliminate as much movement as possible.

IndyZJ
08-04-2010, 03:42 AM
Get some pictures up ASAP please. I remember when you were posting up CAD drawings of your ideas a while back, or at least I think it was you. Glad to hear you made it into a reality. Why do you say a 3-link tends to brake steer?

If it's what I'm thinking about (and the possibly the scariest part of driving a rig with wristed ford radius arms), brake steer is to what happens under hard braking and the suspension has an uneven "give" to it from one side to the other. Under braking the axle tries to rotate forward and the links try to keep it from doing so. With an "incorrect" setup (usually soft joints, not enough seperation, lowers too high, etc.), anti-dive acts predominantly on one side of the axle, allowing one side to dive while the side with the upper fights it. I've only seen this complaint from people who have joints with any kind of significant give in them and/or have the lowers mounted at or above the centerline of the axle, giving the lowers little to no leverage against the axle trying to roll forward under braking.

With a 3 link w/ panhard, if the lowers are at the axle centerline, the upper has to counter most, if not all of the rotational force of the axle. Since the upper pretty much has to go on one side, the force will try to act on that side of the axle. Heims for every joint should keep any deflection from happening, but it would be more "correct" to mount the lowers below the centerline and make them do some of the work. That's what makes sense to me anyway from seeing and driving a few different setups - some good, some not so good.

Hope that makes sense. Drive a bad setup and you'll understand very fast. I have way too much freetime lately to do way too much research on this stuff...

rstrucks
08-04-2010, 10:53 AM
Questions I'd like to see answered:

What kind of seperation should you shoot for at the body/chassis end of the links?

What about link length? I thought the upper link should be around 70% of the lower is that correct?

You can put the third link of the passenger side right? I can't think of a reason not to. There may be a little more room on that side so it may be a viable option. You'd obviously have to build a very strong mount since it will be taller than a mount on the driver side but beyond that is there any downsides to a pass. side upper?

ATL ZJ
08-04-2010, 11:00 AM
What about link length? I thought the upper link should be around 70% of the lower is that correct?

not necessarily. That's what I made mine because I was told that having uppers ~70% the length of the lowers keeps the pinion angle constant throughout the range of travel (and it seems to work), but it's not a hard and fast rule. But nowadays you see a lot of rigs running equal length uppers and lowers so they can carry one spare link that fits in every location...


You can put the third link of the passenger side right? I can't think of a reason not to. There may be a little more room on that side so it may be a viable option. You'd obviously have to build a very strong mount since it will be taller than a mount on the driver side but beyond that is there any downsides to a pass. side upper?

"Let me answer your question with a question"... should the axle-side panhard mount be on the opposite side of the axle-side attachment of the upper link in a 3 link? Or does it even matter? I have never built one personally, but if so, I suspect this is why you see upper links on the driver side in rigs with driver drop axles...

SirFuego
08-04-2010, 11:02 AM
I don't have much to add to this discussion due to only have experience with Clayton's radius arms, but I will say this.

My front uptravel is only about 1/2" more than stock (5" bumpstops on a 5.5" lift) and my downtravel is limited (by limit straps at each side of the axle) to where the coil spring just unseats. I haven't checked my bushings in a month or so, but I haven't noticed any real wear issues with them in the 2+ years I've been running my Clayton's setup that way. The primary reason for setting it up that way was to be able to turn at full stuff and also to keep front driveshaft in check. The bushings seem to be a nice side effect of setting it up that way, though. The geometry of radius arms make them bind -- there is no doubt about that, and I'm not saying that my setup is ideal (I wouldn't mind more droop for going over ledges) but I'm just throwing that out there because they can be setup to prolong the life of the bushings.

One more thing -- I know folks have beat on 3 links HARD without failure, but I'm personally leary of only running 1 upper in the event that it fails. Also keep in mind that in a 3 link, the upper arm sees more force than a 4 link, so be sure to brace the upper brackets accordingly.

Cody -- how much droop does your center limiting strap allow?

ATL ZJ
08-04-2010, 11:16 AM
I will also agree with Cody et al that the center limit strap is the best thing since sliced bread. I use my winch for it, which is nice because it's adjustable, but the motor mount straps work too. I just prefer the winch because I can cinch it down to have about an inch of slack on steep climbs and use my full 10" of droop when I'm haulin arse

Cody
08-04-2010, 01:32 PM
Cody -- how much droop does your center limiting strap allow?

Maybe an inch? I can get a picture tomorrow. I have to work on the rig a little to get it ready for fall wheelin season :D

AgitatedPancake
08-04-2010, 01:47 PM
"Let me answer your question with a question"... should the axle-side panhard mount be on the opposite side of the axle-side attachment of the upper link in a 3 link? Or does it even matter? I have never built one personally, but if so, I suspect this is why you see upper links on the driver side in rigs with driver drop axles...


Last time I saw it brought up, I saw two seperate reasons. One, people preferred the upper link on whatever side the driveshaft is to counter the rotational torque it puts on the axle, the theory that having the link on the opposite side of the shaft might allow the driveshaft to torque/stress extra hard on that mount. The other, people generally didn't like the idea of mounting their only upper link on a single axle tube on the dana axles because of the ability to spin tubes and such. Building it over the diff involves a truss at the same time, so its a double whammy for strength.

downtowncb
08-04-2010, 10:11 PM
DownTownCB, I took off a single upper off of my radus arm setup for a day to see how it felt, under HEAVY braking, the axle would pivot on the soft rubber on the axle end of the lower CA's and would cause a bit of steering slop and a pull to the right. I have heard of it being similar with a three link with any poly or rubber in the setup. I just wanted a setup that would eliminate as much movement as possible.

Alright makes sense to me. Thanks for the photos btw. Definitely something I will look into when I start building on the Jeep more in the future. Are you still using stock rubber bushing for the axle side upper joints or are they press in cartridge types?

FortCollinsZJ
08-04-2010, 11:04 PM
Alright makes sense to me. Thanks for the photos btw. Definitely something I will look into when I start building on the Jeep more in the future. Are you still using stock rubber bushing for the axle side upper joints or are they press in cartridge types?


I bought a pair of those press in 2" Johnny Joints from Currie, the cast mount is the right size for the JJ to hammer in just right, but the passenger side was a bit bigger, so I welded the JJ case into the mount. Worked out great. Definitly better than the OE rubber.

zjeepin
08-05-2010, 11:28 AM
Last time I saw it brought up, I saw two seperate reasons. One, people preferred the upper link on whatever side the driveshaft is to counter the rotational torque it puts on the axle, the theory that having the link on the opposite side of the shaft might allow the driveshaft to torque/stress extra hard on that mount. The other, people generally didn't like the idea of mounting their only upper link on a single axle tube on the dana axles because of the ability to spin tubes and such. Building it over the diff involves a truss at the same time, so its a double whammy for strength.

When i first built my front la's i put a single upper on the passenger side of the diff because it was easiest. It worked ok but i had a lot of axle hop like a radius arm setup and had some pinion wrap too. I believe the axle itself was flexing a little and that scared me so i made another upper, my setup is very similar to fortcollinszj except his uppers are a little closer to the floorpan than mine and i have no bend in my uppers because i have plenty of room with the 4.o...

I run a center limit too, i got my front end bound up really badly at mason jar in june and broke the passenger side one. I put a chain in on that side for gsse and ripped the tab off the axle saturday night.. without it in there i kinda felt like i was wheelin with no pants on if you know what i mean.. the rig just didn't feel right on hill climbs..

I run polyperformance limiting straps that share a motor mount bolt on the unibody end and come to a center tab on the axle. I started with the limit straps completely tight. I had to have a couple of my buddies stand on the hood when i initially installed them. over the last 3 or 4 years that the straps have been on there they have stretched about an inch so there is just a little bit of slack in there..

i bomb down the trails pretty hard too and i never noticed the suspension being limited but im still on coils and blown shocks. im sure when i upgrade to coilovers or ori's it'll be a different story.

rstrucks
08-05-2010, 01:51 PM
I run a center limit too, i got my front end bound up really badly at mason jar in june and broke the passenger side one. I put a chain in on that side for gsse and ripped the tab off the axle saturday night.. without it in there i kinda felt like i was wheelin with no pants on if you know what i mean.. the rig just didn't feel right on hill climbs..

I run polyperformance limiting straps that share a motor mount bolt on the unibody end and come to a center tab on the axle. I started with the limit straps completely tight. I had to have a couple of my buddies stand on the hood when i initially installed them. over the last 3 or 4 years that the straps have been on there they have stretched about an inch so there is just a little bit of slack in there..



Trey - do you have a pic of your limit strap set up? My little brain is having a hard time visualizing it.

Anybody else have pics of theirs?

I evidently need to add a center limit to mine. I run limit straps but they are just to prevent me from overextending my shocks. They both attach to the engine mount bolts at the top.

ATL ZJ
08-05-2010, 02:13 PM
this is a pic of trey's rig and you can almost see the limit straps... they run on each side of the oil pan and are taut in the pic

http://img.photobucket.com/albums/v125/atlzj/IMG_0671.jpg

DaveJeep
08-05-2010, 02:34 PM
I'm thinking I will try a center limiting strap on mine. Although I have not had any unloading problems but the terrain here is probably a lot different than yours, no rock crawling just trail running.

I run a radius front setup (JJs on the frame side, heim on the upper at the lower point, all rubber bushings at the axle) and 4 link rear (all JJs) with a Antrirock bar back there. I've never has a problem in the year I've owned it with the rubber bushings going bad.
http://i273.photobucket.com/albums/jj231/blackss2005/IMG_1749.jpg
http://i273.photobucket.com/albums/jj231/blackss2005/IMG_1750.jpg
http://i273.photobucket.com/albums/jj231/blackss2005/IMG_1751.jpg

SirFuego
08-05-2010, 02:40 PM
I run polyperformance limiting straps that share a motor mount bolt on the unibody end and come to a center tab on the axle. I started with the limit straps completely tight. I had to have a couple of my buddies stand on the hood when i initially installed them. over the last 3 or 4 years that the straps have been on there they have stretched about an inch so there is just a little bit of slack in there..

I think I might try this. I like the idea of running two "triangulated" limit straps rather than running a single one. You figure the limit straps need to hold the entire front unsprung weight plus whatever force the compressed springs are putting on the axle. In addition, it seems like it would also act as a pivot point during articulation, so that may or may not add even more force to the straps. I'm thinking that I'll be able to drill a hole in my truss on the axle side.

EDIT: So I'm also thinking that I might be able to adjust my side limiting straps to allow for more downtravel since the center straps will in essence control the axle droop and keep the driveshaft angles in check.

When you mean the motor mount bolts on the unibody side, I assume you mean the long bolt that goes through the motor mount bushing parallel to the "Frame" rail?

zjeepin
08-05-2010, 03:33 PM
I think I might try this. I like the idea of running two "triangulated" limit straps rather than running a single one. You figure the limit straps need to hold the entire front unsprung weight plus whatever force the compressed springs are putting on the axle. In addition, it seems like it would also act as a pivot point during articulation, so that may or may not add even more force to the straps. I'm thinking that I'll be able to drill a hole in my truss on the axle side.

EDIT: So I'm also thinking that I might be able to adjust my side limiting straps to allow for more downtravel since the center straps will in essence control the axle droop and keep the driveshaft angles in check.

When you mean the motor mount bolts on the unibody side, I assume you mean the long bolt that goes through the motor mount bushing parallel to the "Frame" rail?

i use the bolt that attaches the motor mount to the unibody. i thought about using the bolt that goes through the actual bushing but i thought that would put alot of leverage on the unbody as well as the engine block. Mine have been this way for probably 4 years without issue.

another benefit if the triangulated center limit strap when used with a panhard bar is that as the axle moves side to side during articulation one strap will tighten and one will loosen (depending on up or down travel) and acts like a suckdown..

i've never run any limit straps at the front tires with this setup either, my thinking is that the center strap holds the majority of the unsprung weight anyway. my theory could be flawed but it has worked well to this point and i've never broken a shock..

i highly recommend the center limit straps for those who haven't tried it.

if you don't want to spend $50 on nice limit straps just to try it out you can use chain temporarily, because it will be harsh and unless you get some heavy duty chain you'll break a link eventually

ATL ZJ
08-05-2010, 03:49 PM
if you don't want to spend $50 on nice limit straps just to try it out you can use chain temporarily, because it will be harsh and unless you get some heavy duty chain you'll break a link eventually

there is also a guy on pirate selling no name limit straps for cheap. I picked up a pair of 20" quad wrapped straps for $30 shipped the other week.

SirFuego
08-05-2010, 04:04 PM
Trey -- quad or double wrapped straps?

zjeepin
08-05-2010, 04:08 PM
there is also a guy on pirate selling no name limit straps for cheap. I picked up a pair of 20" quad wrapped straps for $30 shipped the other week.

awesome, post up his user name or something, the replacement i bought from polyperformance is too short so i need to return it anyway..


Trey -- quad or double wrapped straps?

I was running double wrapped until i broke one on mason jar at gsse prerun.. now polyperformance only sells quad wrapped..

SirFuego
08-05-2010, 04:11 PM
I'm guessing that this is it:
http://www.pirate4x4.com/forum/showthread.php?t=855647

You of course need to be a red star member at pirate to see it.

zjeepin
08-05-2010, 04:24 PM
thanks jared.. i've got a request in to him already..

ATL ZJ
08-05-2010, 04:24 PM
I'm guessing that this is it:
http://www.pirate4x4.com/forum/showthread.php?t=855647

You of course need to be a red star member at pirate to see it.

yeah PM this guy: http://www.pirate4x4.com/forum/member.php?u=85972

whoops too late

zjeepin
08-05-2010, 04:26 PM
i hate it when that happens!

so for reference sake..

when designing a tri-4link how much triangulation is required to center the axle without constantly destroying rod ends or bushings?

I recently triangulated my rear lowers for ground clearance sake, i wasn't really looking for that to center my axle because my upper a-arm does that work but i also recently had the upper link out for some rework and noticed that the lowers weren't doing very much to centering..

im using my rear suspension as an example but im going to be triangulating my front uppers soon..

ATL ZJ
08-05-2010, 04:38 PM
IIRC 40 degrees combined is about the minimum

zjeepin
08-05-2010, 04:44 PM
so 20deg per arm?

so at a minimum you want 1/2" of triangulation for every 1 inch of arm length? (more or less)

i imagine at some point in triangulation you start to adversely effect your anti-squat by over triangulating because the more you triangulate you are essentially shortening the arm..

rstrucks
08-05-2010, 04:46 PM
IIRC 40 degrees combined is about the minimum

Yeah that is the same number that is rolling around in my head.

ATL ZJ
08-05-2010, 04:47 PM
so 20deg per arm?

not necessarily... you could tri the uppers and lowers however much you want/can fit, individually, just as long as they add to >= 40

rstrucks
08-05-2010, 04:47 PM
so 20deg per arm?

I think if you have a total of 40 deg. whether it is all lowers, all uppers or uppers and lowers combined you are ok. Somebody PLEASE correct me if I am wrong.

EDIT - seconds late!

zjeepin
08-05-2010, 04:52 PM
not necessarily... you could tri the uppers and lowers however much you want/can fit, individually, just as long as they add to >= 40

hmm so if all 4 arms are at 10deg the axle will center? doesn't seem like enough

ATL ZJ
08-05-2010, 04:55 PM
i imagine at some point in triangulation you start to adversely effect your anti-squat by over triangulating because the more you triangulate you are essentially shortening the arm..

I highly encourage using the calculator... it is stupid simple to use and having built suspensions with and without the calculator, they definitely come out better when you use it...

just watch what added triangluation does to the rest of the susp. characteristics as you move your points around in the calc. within the constraints of the frame/ mounting locations you have to work with... I would shoot for AS in the range of 65-100% in the front, just like you would in a rear suspension.

rstrucks
08-05-2010, 04:56 PM
hmm so if all 4 arms are at 10deg the axle will center? doesn't seem like enough

If you have two arms opposing each other at 20 deg. each (40 total), that would essentially be the same as having your lowers angled in at 10 deg. ea (20 total) and you uppers angled out at 10 each (20 total). Right?

Your right though - 10 degrees on each arm doesn't sound like much but when they are in opposite directions it adds up.

SirFuego
08-05-2010, 04:56 PM
There was a more recent thread on Pirate regarding that and the 40 degree total angle popped up. This isn't it (I can't seem to find the right search terms), but here is an older thread on the same topic:
http://www.pirate4x4.com/forum/showthread.php?t=208474&highlight=triangulation+total+angle

rstrucks
08-05-2010, 05:00 PM
I highly encourage using the calculator... it is stupid simple to use and having built suspensions with and without the calculator, they definitely come out better when you use it...


Cam, do you have a link to the calculator you are talking about? I'm sure I could Google it and find one but I thought if you had one handy it might be worth sharing.

EDIT - here is the first one that came back on a quick google search - http://mysite.verizon.net/triaged/4linkcalcv15html/index.html

ATL ZJ
08-05-2010, 05:10 PM
maybe... not familiar with any web based ones... it has been a while since I used it but here's the excel calc I used: http://mysite.verizon.net/triaged/files/4BarLinkV3.0metric.xls

ATL ZJ
08-05-2010, 05:18 PM
oh... also, this is a pretty cool survey of 4 links among a group of rigs that see the same terrain:

http://www.azrockcrawler.com/_images/tech/2007/6-27-074link/4linksurvey.html

it's about rear suspensions but everything I've been told about building a tri 4 link front suspension is to build it like it's a rear. so it might at least give you guys some baseline numbers to work from, even if the upper links need to be spread out wider on the axle side to clear oil pan, crank pulley, etc

zjeepin
08-05-2010, 05:22 PM
very nice! now this is a good totm

zjeepin
08-06-2010, 12:07 PM
maybe... not familiar with any web based ones... it has been a while since I used it but here's the excel calc I used: http://mysite.verizon.net/triaged/files/4BarLinkV3.0metric.xls

wait a minute.. you used a metric calcuator?

SirFuego
08-06-2010, 12:14 PM
I think this is the one he meant to post for us Americans who don't use metric calculations:
http://www.pirate4x4.com/forum/showthread.php?t=204893

The first link I believe is the most recent. There is also a link to the 3-link calculator in that thread, too.

I asked this before, but don't recall getting much of a response and this seems as good of a thread as any. When designing a front suspension, is it done completely independent of the rear suspension? Or can you design it to counteract some of the characteristics of the rear suspension?

zjeepin
08-06-2010, 12:36 PM
I think this is the one he meant to post for us Americans who don't use metric calculations:
http://www.pirate4x4.com/forum/showthread.php?t=204893

The first link I believe is the most recent. There is also a link to the 3-link calculator in that thread, too.

I asked this before, but don't recall getting much of a response and this seems as good of a thread as any. When designing a front suspension, is it done completely independent of the rear suspension? Or can you design it to counteract some of the characteristics of the rear suspension?

i don't know about the two counteracting each other but you do want the same properties as far as antisquat, instant center in the front as you do a rear.. like cam said a few posts up..

downtowncb
08-06-2010, 05:22 PM
I asked this before, but don't recall getting much of a response and this seems as good of a thread as any. When designing a front suspension, is it done completely independent of the rear suspension? Or can you design it to counteract some of the characteristics of the rear suspension?

I don't know about all the intricacies of the link geometries in relation to each other but I know as far as spring rates go you want the rear to be about 10-20% stiffer relative to the wheelbase. This is so the rear can react as fast as the front is when driving at speed and not create pitching.

ZJ TINS
08-06-2010, 05:37 PM
Ok having read so far, why is the 4 link always better than the radius arm? For example, for my 95% DD 5% offroad with 4 " of lift, is the 4 link really going to do much more than a radius arm? I mention this due to the cost difference. Is it really worth the money and if so why?

As for caster, by getting adjustable arm's then I can point the axle to any angle I want in it (within reason).

With rubber on the axle side and johnny joint on the frame, for 4" of lift I really do not see that binding, the arc or angle is not great enough. I will double check this later when I get under the ZJ and force it to full compression on one side and droop on the other see what happens. Plus I plan on adding the center strap with 1" of play per Cody.

IndyZJ
08-06-2010, 09:14 PM
With a properly designed 3 or 4 link, you can get much better (lower number) anti-squat/ dive than with radius arms. Dual radius arms also bind no matter what height or travel you run by their nature. If there wasn't any give in the joints or bushings, a radius arm suspension would not articulate at all.

Side note: On street rods that run solid front axles with radius arms with rod ends/ clevises, the flex actually comes from a forged axle beam. Guys who run radius arms on tube axles end up braking something.

With only 4" of lift, the arms would be relatively flat and you probably wouldn't notice the downsides of radius arms on a rig that sees little trail time. Wearing bushings out usually happens when you spend a lot of time articulating the front end - on the street, it shoudn't be an issue. Throw in the center limit strap(s) and you shouldn't have a problem with the front end trying to unload from higher anti-squat/dive on climbs.

ZJ TINS
08-07-2010, 01:58 PM
Ok so I just measured my ZJ bolt to bolt distance from the motor mounts and it is 24".

So this means from the center of the axle to the motor mount bolt is just under 18" inches for my lift. Given an 1 1/2" tab height (to the hole center or maybe a 2 1/2" tab total height) and that is just under 14 " so according to Cody that means I order 15" straps and triangulate off that. Thats about 1.2" of slack which I can adjust via tab hole height.

ZJ TINS
08-07-2010, 11:01 PM
FYI 16" (a little longer i thought) quad thick straps for a pair are $30 shipped to my house. nice!


straps (http://www.pirate4x4.com/forum/showthread.php?t=855647&highlight=straps)

ZJ TINS
08-08-2010, 12:58 AM
ON the anti squat, what is the bad results i.e., how does the vehicle behave with poor anti squat? also what numbers are minimum (below the vehicle is not safe or some other descriptive term) and good (neutral or does not behave any different even thought anti squat number can get better). Did alot of searching and i still do not get a feel for what it means (other than low is good high is bad) .

IndyZJ
08-08-2010, 02:24 AM
In my experience, over 100% anti-squat means jacking under load, where lower than 100% will squat. For our applications, you generally don't want your suspension to "jack" under load, especially in a climb. In extreme cases, too much antisquat will literally try to drive the axle under the vehicle. That's the case with my YJ's last suspension - the procrap coil conversion my dad put on when it was cool about a decade ago (the geometry is TERRIBLE). Most coil-sprung Jeeps lifted high on short arms do the same thing.

As has been said, a center limit strap will not allow this to happen, at least not further than the strap will stretch.

edit: With radius arms, the geometry basically is what it is. I'd just make the arms as close to horizontal as possible without killing ground clearance. A center limit strap will go a long way to cover up the high antisquat that tends to come with them.

AgitatedPancake
08-08-2010, 04:06 AM
One of my videos perfectly captures nasty antisquat driving my rear axle down and forward. That actually brings up another point, this video also shows how a single triangulated rear 4-link rear steers massively and wants to drive the rear axle up under the jeep.

So heres the link: http://www.youtube.com/watch?v=9G1VBnguT9k

Look at the segment starting at 2:10 when I lose my coil. Thats a pretty severe uphill, so most the weight of the jeep is on the rear end. The rear axle pushes way away from the body and pushes the jeep away from the rock surface. At the same time I'm lifting a front tire without maxing out it's shock, which is showing the binding and unloading on a radius arm. I'd bet that front axle would have tried harder to stick to the ground with a 3 link, not so ready to lift a tire on a climb.

Then at like 3:50 I'm trying to stop my jeep from rolling, but the suspension keeps binding up and pinching, pushing the body up into the air. This part is just really good for actually watching the rear end steer and move as the suspension articulate, because it goes from full bump to full stuff in a split second.

ZJ TINS
08-10-2010, 10:22 AM
FYI I looked at the the link calculator and found the most critical dimension by far to get the anitsquat down is the height difference from the top arm to bottom arm on the frame end. Put both underneath the belly and that is hard to do. I am kinda wondering if this is being overthought since most of the kits out there (good ones) use radius arms up front.

ATL ZJ
08-10-2010, 12:05 PM
FYI I looked at the the link calculator and found the most critical dimension by far to get the anitsquat down is the height difference from the top arm to bottom arm on the frame end. Put both underneath the belly and that is hard to do. I am kinda wondering if this is being overthought since most of the kits out there (good ones) use radius arms up front.

keep playing... you have just discovered the tip of the iceberg...

having run both a one-size fits all suspension kit and a true tri 4link I designed, I will say that radius arm kits suck in comparison...

rstrucks
08-10-2010, 01:40 PM
Can you guys that have completed a custom front 3 link or 4 link build post up some pics (or a link to a build thread) of your suspension? I think having some pics for reference would really add to the thread. If you have any that show mounting points at the axle and at the body/frame along with some "flex" shots, that would help people decide what route they want to go. Also, if you have extensively modified an existing "kit" post those pics too.

If you have measurements, angles, seperation, anti-dive %, etc... that info would help as well.

I know a lot of people (me included) are considering building a custom system and would like to see more info to help them decide what to go with (3 link, 4 link, radius arm).

ZJ TINS
08-11-2010, 11:05 AM
One thought (may have been done already):

run the upper from stock axle location to back wall. place it as far down as you can go except keep the pivot point 6 inches above the lower arm pivot point.
run the lower arm in the stock axle location and run back 42+ inches to underneath belly. trade off ground clearance vs distance from top long arm pivot point to gain anitsquat.

I think I am going to get some 2 in pvc pipe to play with geometries and see what I come up with for clearances and such.

zjeepin
08-11-2010, 11:26 AM
I'm going to be redesigning some of my rear suspension over the next few weeks. Im trying to figure out how to post up my calculator work along with pics so hopefully we can all learn something..

i've got my johnny joints in and link material so i'll be diving in over the weekend..

since this is a front suspension discussion should i start a new thread?

rstrucks
08-11-2010, 03:59 PM
since this is a front suspension discussion should i start a new thread?

Nah, post up what you can. If need be I can move the info into the rear suspension TOTM that is not too far in the future, or we could even change the title of this thread to simply "suspension". The more you can share the better, we'll all benefit. :smt023

SirFuego
08-11-2010, 04:16 PM
Im trying to figure out how to post up my calculator work along with pics so hopefully we can all learn something..

Print Screen takes a screenshot. Paste it into Paint and crop it.

If you have a Mac, I'm of no help...

zjeepin
08-11-2010, 04:53 PM
Print Screen takes a screenshot. Paste it into Paint and crop it.

If you have a Mac, I'm of no help...

nah, im working in windows xp..

i got it pasted into paint with cams help, just gotta get it cropped small enough to upload and big enough to read.. will probably mess with it this evening..

ATL ZJ
08-11-2010, 05:21 PM
Trey use this, it can both resize and host for you

http://www.imagesocket.com/

then just put tags around the link like this [img]picname

or if you just need to resize, http://www.picresize.com/

zjeepin
08-11-2010, 05:29 PM
Thanks, will do...

ZJ TINS
08-11-2010, 09:59 PM
Free and decent picture tool is irfanview. Just do a search (CNET has it). Re-sizes, ,changes type, can reduce picture content several ways to make is smaller yet readable, shading , color, etc.

paulkeith
08-12-2010, 10:03 AM
There is a windows xp "powertoy" available from microsoft that can resize pictures. It adds "resize" to the options that appear when you right click on an image. It can do individual or bulk. No cropping though.

zjeepin
08-12-2010, 10:40 AM
so i tried for about an hour last night to resize and post but by the time i had them small enough to upload you couldn't read the text in the fields..

i have them in my photobucket acct if anyone feels like messing with it..

ZJ TINS
08-12-2010, 01:45 PM
Try irfanview (http://www.irfanview.com/). Their is an option to put it into internet 'size' that works very well.

ATL ZJ
08-12-2010, 01:55 PM
so i tried for about an hour last night to resize and post but by the time i had them small enough to upload you couldn't read the text in the fields..

i have them in my photobucket acct if anyone feels like messing with it..

if they are on your photobucket, just post the links...

and if you are uploading to photobucket, you probably don't even need to resize because they won't be attachments

ZJ TINS
08-12-2010, 02:00 PM
So I measured my ZJ again and here is what I found;

Upper arm, stock length 15 ", long arm cut off frame upper and lower frame brackets and create new bracket so the long are is aproximately parrallel to the ground and arm is 20-21" bolt to bolt.

Lower arm, stock length is 15.5", extend from axle stock mount to 34"-40" and mount to new backet welded to the frame.

The above results with an anti-squat below 40% depending upon actual final lengths and heights.

The only thing left is to decide on lower arm length. Shorter means stronger from a bending perspective. Longer results in a smaller angle but for the dimmensions I have longer does not seem to affect anti-squat much. Any thoughts?

ATL ZJ
08-12-2010, 02:45 PM
Besides clearance concerns, the angle and the length of your lowers is less significant than the relationship of the length of your lowers to the length of your uppers. The amount of convergence of the uppers and lowers on the frame side is also something to think about... you usually want a little less vertical separation on the frame side than the axle side.

How does adjusting the length of your lowers affect the location of your instant center and your roll axis characteristics?

And what is everybody using for a COG estimate?

ZJ TINS
08-12-2010, 04:21 PM
I was curious about the other parameters. Any idea what value they should be at or the relationship they establish? For instance roll center, do I care?

My wheel base is 105.9, the spec for a ZJ , the tool had 109 to start. All other I left intact. I will look and see if they change the anti-squat much at for provisional design.

I case anyone is wondering using the factory axle mount approach does not triangulate enough to eliminate the track bar. But since I already have a heavy duty adjustable one it doesn't matter. But my current cost estimate is below $280 DIY.

ratmonkey
08-12-2010, 04:58 PM
You can't eliminate the track bar without going double triangulated and full hydro steering. The steering puts more lateral force on the axle than only triangulation can handle. You'd be popping joints out all the time.

IndyZJ
08-12-2010, 05:50 PM
You can't eliminate the track bar without going double triangulated and full hydro steering. The steering puts more lateral force on the axle than only triangulation can handle. You'd be popping joints out all the time.

That would only be true if you were running crappy or severely undersized joints and/ or did not have enough triangulation in the suspension.

The main reason to go to full hydraulic steering with a triangualted front suspension is to avoid the bumpsteer that would result from the arc the the drag link follows through its travel and the axle no longer following the same/ similar arc because of the lack of a panhard bar. Full hydraulic steering also simplifies other things that tend to go with a triangulated front suspension like moving the axle forward and potentially gaining more uptravel without extensive chassis modification along with the increased steering force required by larger tires someone with that configuration would likely run.

There are other ways to configure the steering to eliminate bumpsteer with a triangulated front suspension (like a push-pull setup) but none that are really practical unless you built the rig around it or just lived with significant bump steer.

ZJ TINS
08-13-2010, 09:54 AM
For my lift and reuse of the axle mount approach, i don’t see the parameters change much… maybe 5% for fairly extreme changes in individual parameters, with an exception of the height difference and parallelism of the top and bottom arms themselves drastically affect the anti-squat. A marginal approach seems to have some popularity in the putting the top arm frame end near the bottom arm frame end within a couple inches. This give anti-squat between 96 and 105 %.
My shorter arm and careful place gives me sub 40% range.

Also the long arm close frame end approach changes pinion angle to +5 at 4" up and +7 at -8”. The shorter are approach gives 1.4 at 4" up 3.3 at 8" down.
So the long arm close together puts more stress on the u joints that the shorter arm approaches.

ZJ TINS
08-13-2010, 10:01 AM
So it looks straight forward, rubber in front johhny joints in the rear. Now just have to decide if it is worth it to get the arms set up to rotate to change lengths (threaded both ends one reverse).

Also with bottom arms in the sub 38" length means no interference with the cross brace I can do anything with that (as in leave it alone, I like Kevins old design).

Still plan on getting some 2" PVC and try some fits and do compression droop tests.

Also I can custom make/fit some frame stiffeners while I am at it.

zjeepin
08-13-2010, 01:33 PM
if they are on your photobucket, just post the links...

and if you are uploading to photobucket, you probably don't even need to resize because they won't be attachments

i've had alot going on the past few days i'll get it posted up hopefully on sunday.. im going to the ecors race in harlan saturday... holla!

ZJ TINS
08-14-2010, 12:24 AM
Found a couple things: roll axis you want as close to 0 as you can. Travel roll axis is the same except when you droop or bump its the current roll axis. That should be kept small also.

Pinion change needs to be near near 0.

You also want to keep the arms parallel to each other first and the and the ground second. At least when i do the numbers for everything come out a lot easier to optimize the multiple parameters.

If the arms are parallel then this 70% arm length ratio does not mean anything. In fact if they are parallel the arm ratio has little meaning. So you have put your arm where you want. Remember i am only looking at +4" bump and 8" droop or so. You guys going much higher would need to mess with the setting and see if it hold true.

rstrucks
08-27-2010, 10:39 AM
Bump.

Hypothetical - if you were building a custom suspension to replace your existing long arm kit, would you do the front first or the rear. (this would be over a extended period of time)

ATL ZJ
08-27-2010, 01:16 PM
I'd start on the rear because there is less to work around. It's usually easier to build without any steering to complicate things...

ZJ TINS
08-27-2010, 04:19 PM
Some more info on the 4 link calculator:
The roll axis angle defines oversteer(+) or understeer(-). Ideally you want a slight understeer. However multiple articles on different vehicles indicated near zero ( +-3 degrees) is not noticeable is most situations. This is especially true when dealing with a lifted vehicle and offroading. However severe understeer and oversteer could be potentially uncontrollable is certain situations. To me this means keep is near zero and then do not worry about small changes.

I also noticed different ratios (arm lengths, angles of arms etc) can give you almost the same anti-squat and roll axis angle but allow the pinion angle to either change greatly or very little. So is seems prudent to get your design close, then tweak it to get the pinion angle change low for the delta between the maximum bump ciondition and maximum droop conditon.

BigDaveZJ
08-27-2010, 07:58 PM
Bump.

Hypothetical - if you were building a custom suspension to replace your existing long arm kit, would you do the front first or the rear. (this would be over a extended period of time)

If the rig was down for the whole time it wouldn't much matter to me. As for "bang for the buck" I think the front would gain the most. Although it also needs to be the most detailed. If it was someones first custom suspension build I would say do the rear first, and use what was learned in that process when you move on to the more complicated front.

AgitatedPancake
08-27-2010, 09:12 PM
I've been looking at taking my claytons, and inboarding the lowers with minimal modification to turn it into a dual triangulated and remove some of the axle steer characteristics I'm getting. I'll be doing a front 3 link before that happens though, simply because if I'm going to build the bracketry for the new axle might as well do it right

ATL ZJ
09-08-2010, 09:50 AM
Here's a good example of a suspension behaving nicely

NI4SoBihxQQ

zjeepin
09-12-2010, 02:32 PM
thanks for posting that cam... doesn't even look like my tires spun and its clear I dumped the clutch pretty hard. I really gotta take the time and post my rear link photos and calculator screenshots..

northgazj
12-06-2010, 12:30 PM
Bringing back up a slightly old thread for some advice.....

Anyone with a 5.9 running triangulated front limiting straps? I wanted to see what your choice for the driver side unibody end mounting was. I only see one motor mount bolt on that side that is in a good position and it's coming through the unibody and the motor mount, but the nut is welded to the motor mount. Is it safe to run a longer bolt and attach it there? Just doesn't seem like a strong setup to me, but I could be wrong.

These are going to be a must with my new setup which is a HP 44, extended radius arms back to a Clayton's crossmember. I'm not running a sway bar currently and it hasn't been a real issue up to this point, but I do feel the front end's tendency to unweight.

rstrucks
12-07-2010, 11:34 PM
Anyone with a 5.9 running triangulated front limiting straps? I wanted to see what your choice for the driver side unibody end mounting was. I only see one motor mount bolt on that side that is in a good position and it's coming through the unibody and the motor mount, but the nut is welded to the motor mount. Is it safe to run a longer bolt and attach it there? Just doesn't seem like a strong setup to me, but I could be wrong.


I don't run a triangulated strap (yet) but this may apply anyway. I have my front limiting straps attached to the engine mount isolator bolt. It probably isn't the best option but it has worked well for me. For the amount of time the mount has seen extra stress due to the front axle weight hanging off of it, it hasn't been an issue. The rubber isolator looks just like it did before the strap. YMMV.

northgazj
12-09-2010, 12:07 PM
Thanks. That looked like the best place, but I was nervous to run it off of those bolts. I thought the lateral stress from triangulated straps would be an issue.

moparrr07
02-18-2011, 01:03 AM
front axle in front of crank pulley for maximum performance and best weight dist.



can you elaborate on this?

this hasnt really been covered at all that i have seen,

what is everyone running for wheelbase?

can you push it forward too much?

same question for rear axle back?

any related info for how far to push your axles?

( i figured this was the best place for this question)

IndyZJ
02-18-2011, 02:05 AM
can you elaborate on this?

this hasnt really been covered at all that i have seen,

what is everyone running for wheelbase?

can you push it forward too much?

same question for rear axle back?

any related info for how far to push your axles?

( i figured this was the best place for this question)

1. Weight distribution.

2. Cam's setup doesn't exactly apply to the average ZJ.

3. It depends.

4. In short, like most things, "ideal" wheelbase depends largely on terrain and driver preference. I would say that most here who push their axles out do so for tire clearance as necessary on (more or less) full bodied rigs. It's up to you to determine the details for your rig.

SirFuego
02-18-2011, 10:25 AM
can you elaborate on this?
I'm going to guess weight distribution -- especially on a buggy setup. When you chop out the rear, the rig becomes very front heavy. Doing what Cam mentioned sort of puts the engine "between" the axles for a bit better weight distribution. Depending on your suspension setup, that may also afford you better uptravel as the stock location limits you by the oil pan. It will of course give you a better approach angle, too, because there is less overhang in the front.


what is everyone running for wheelbase?
108 right now. That's because the high clearance brackets pushed my rear axle back 2 inches. I'm going to suspect that when I swap in 1tons, that I'm going to end up around 110 (at least) because of the way the brackets are going to be setup on the front axle (in line with the axle tubes). Ideal wheelbase depends heavily on the terrain you wheel on. Wheelbase can be a hindrance on tight/twisty trails where I live, but it can be a huge help in more "open" areas like the desert since a long wheelbase tends to climb better. The less sheetmetal you have, the less hindrance wheelbase becomes in tight trails.


can you push it forward too much?
If you don't swap out or relocate other things -- yes. Besides the obvious limitation of control arms (which you can always lengthen), your drag link and trackbar can be problematic if you go too far forward. If you convert the steering over to full hydro (removes the drag link), all you need to worry about is the trackbar angle -- which you can eliminate if you get creative and put in a double tri 4 link. I've never tried to push my front axle forward, so I don't know what the practical limit is before you need to worry about the trackbar and draglink.


same question for rear axle back?
If you push the rear axle back too far, you can run into gas tank clearance issues. Don't quote me on this, but I think 3 or 4 inches (depending on your setup) is about where you start to run into problems. Of course if you relocate your gas tank, you don't need to worry about it. Pushing the rear back gives you a better departure angle.

But if you are going full-on buggy, your "best" way to increase wheelbase will probably be to push the front axle forward (if possible). IMO, approach angle is more important than departure angle since you can usually drag the rear bumper over anything.

ATL ZJ
02-18-2011, 10:25 AM
The reason I said that pushing the front axle forward is ideal is because ZJs are typically front heavy. For anyone with a grand wanting to stretch their wheelbase, I'd recommend pushing the front axle forward instead of the rear axle back.

Obviously within the platform of a full bodied ZJ you'll have constraints.

My wb is 114 and I would not run a wheelbase that long with anything smaller than 39s. With my low belly it's already bad enough. But it does help a lot with stability on our hillclimbs here in SE.