TOTM: All About Axles

[Jeeptech01]

I would imagine it is because the center piece is pushing up against the pumpkin rather than being pulled away from it. But that is just speculative.

[Jrgunn5150]

Good info on the SD axles!

As for hp44's I picked up a HP44/9 combo for my pickup to SAS it, out of a 78 Bronco and the radius arms are cast FWIW. I think 77 to 79 are cast, not sure though. Ford does alot of wierd things too.

[BigDaveZJ]

Never really thought about it, but why is it stronger on the bottom?

I remember reading something similar at one point. I think it had to do with building a JeepSpeed rig so the strength was a bit more important than the ground clearance.

[Kauzi Zj]

Ok, because Im trying to learn as much about this as possible I have 2 questions, why does welding the tubes help, and how and why does a truss on an axle increase strength, I was under the understanding that the breakages are generally internal moving parts, so how does strengthening the housing help?

[BigDaveZJ]

John,
The tubes are already welded to the housings a little bit, but typically it's just a couple plug/rosette welds. By welding the tube to the housing where the tube actually enters the housing you can greatly decrease the chance of spinning the tubes in the housing.

The truss basically makes sure that the axle stays straight and true.

If you visualize the forces applied to the axle the truss will add a bunch of strength to the housing to keep it from bending.

[SirFuego]

Ok, because Im trying to learn as much about this as possible I have 2 questions, why does welding the tubes help

On most axles, the axle tube is usually just pressed into the housing with a couple welds holding the tubes in. It is possible that given the right situation, a tube can "spin" in the housing. Welding the tubes to the center section basically means that the welds need to break (unlikely) before the tube spins. If a tube spins, it can throw off your axle bracketry.

, and how and why does a truss on an axle increase strength, I was under the understanding that the breakages are generally internal moving parts, so how does strengthening the housing help?

Strengthening the housing prevents it from flexing due to the vigors of being offroad. When you set up a ring and pinion, they need to be setup so that the gears mesh properly. When a housing flexes, it can cause the ring and pinion to "deflect" temporarily (think of both tubes bending upwards at the same time) -- which can sometimes be enough to throw them off to the point that they break.

Another thing about a truss is that it prevents the axle tubes from bending during a hard hit or jump. If the truss, however, doesn't span as far as it can (flange to flange in the rear or C to C in the front), the tubes will just try to bend where the truss ends. This happened to a friend's axle who was just running the Clayton's truss. On a coil spring setup, though, it can be difficult to design a truss that spans the whole ale. A bent tube puts more stress on the axle shafts. More stress on the axle shafts makes them more prone to breaking.

As for the Top vs. Bottom truss, I've been told that a bottom truss is stronger by other people with racing backgrounds. From my understanding, the forces are better distributed on a bottom truss given the expected forces seen on an axle during jumping, drop offs, etc.

[AgitatedPancake]

Aaactually dave you proved the point perfectly with that post. That style 9" has the axle tubes that are literally butted up to the center section and welded up, you can see the seams in that picture. That truss is the perfect solution, because it helps prevent failures like Brian (FearTheDentist) did with his currie 9"...

[JohnBoulderCO]

I'd want to narrow it to a width close to the 8.8. I know most people go waggy width but Im not sure how that compares to the 8.8

I have a HP44 out of a F250 (78,79) that was narrowed to Waggy width = 62.5" with a 5x5.5 bolt pattern. That's close enough for the WJ. I measured the width and here is another source. http://www.universityofjeep.ca/wag_f...4_install.html

The axle has the thick walled tubes, but I still added a TnT Truss. It came with Superior alloy shafts, an ARB and CTM's.

I matched my Explorer 8.8 by using Spidertrax 1.25" wheel adapters (5x4.5 to 5x5.5).

I like it being a HP axle, added strength and that it has hubs, so I have zero drive line vibes at 80mph.

A pretty strong axle combo (HP44 and 8.8) for 35"-37" tires and you can get off the shelf axle shafts, as opposed to having custom width axles.

[Mtn WJ]

John, the axle you have is in my opinion is the perfect solution for WJs up to 37 inch tires or so.

[BigDaveZJ]

Aaactually dave you prooved the point perfectly with that post. That style 9" has the axle tubes that are literally butted up to the center section and welded up, you can see the seams in that picture.

D'oh. Dunno WTF I was thinking, I knew that, lol. Editing post now.

[Jeeptech01]

I have a HP44 out of a F250 (78,79) that was narrowed to Waggy width = 62.5" with a 5x5.5 bolt pattern. That's close enough for the WJ. I measured the width and here is another source. http://www.universityofjeep.ca/wag_f...4_install.html

The axle has the thick walled tubes, but I still added a TnT Truss. It came with Superior alloy shafts, an ARB and CTM's.

I matched my Explorer 8.8 by using Spidertrax 1.25" wheel adapters (5x4.5 to 5x5.5).

I like it being a HP axle, added strength and that it has hubs, so I have zero drive line vibes at 80mph.

A pretty strong axle combo (HP44 and 8.8) for 35"-37" tires and you can get off the shelf axle shafts, as opposed to having custom width axles.

Thanks for posting that. So yours had the welded on wedges then? It appears that with 1.25" spacers the exploder 8.8 will only be .25" narrower than the waggy width hp44. I'll be keeping an eye out on my local CL.

[IndyZJ]

Thanks for posting that. So yours had the welded on wedges then? It appears that with 1.25" spacers the exploder 8.8 will only be .25" narrower than the waggy width hp44. I'll be keeping an eye out on my local CL.

F250 = no wedges, but there is a good amount of "extra" casting on the driver's side for the leaf spring perch that could probably be cut off like on a 60. There is a lot of extra material on the f250 center section, and the tubes are beefy, especially compared to a f150 stuff. I have both in the garage - I was building the front of my YJ around the f150 axle with cast wedges, but when I went to fill it with fluid, it started leaking at the tubes and plugs welds. It apparently spun the tubes at some point, because upon closer inspection I could see that the plug welds were boogered up and it was leaking at those, too. Thankfully it was free...

It's not worth getting retubed, but maybe I'll make a super cheap 44/9" or hp30 with 44 Cs and knuckles out of the extra junk I've got sitting around for the ZJ. In case anybody's interested, 44 and 9" spiders are somewhat interchangeable. I don't know if it would work as an open dif, but it's definitely close enough to weld together, so it's possible to built a 44/9 with no aftermarket parts - you just have to figure out something for seals.

[rstrucks]

Never really thought about it, but why is it stronger on the bottom?

I think it's because plate steel is stronger in tension than in compression, making it easier to fold the steel on top than it is to pull it apart on the bottom...... in theory.

Correct me if I'm wrong.

[Jeeptech01]

F250 = no wedges, but there is a good amount of "extra" casting on the driver's side for the leaf spring perch that could probably be cut off like on a 60. There is a lot of extra material on the f250 center section, and the tubes are beefy, especially compared to a f150 stuff. I have both in the garage.

So candidates for the hp44 are as follows

F250 (years?) much beefier housing
F150 78-79
Bronco ?years

I have been doing a bit of searching but I take what I read on the net with a grain of salt. Most guys on here, I'll take them at their word. Dont want ya'll to think Im being lazy.

Would there be room to set the f250 housing up for coils links etc once narrowed?

ed: Found this local. Am I headed the right direction?

http://tampa.craigslist.org/hil/pts/1972008256.html

or this http://tampa.craigslist.org/pnl/pts/1947182467.html looks like it still has the radius arms on it.

[SirFuego]

I think it's because plate steel is stronger in tension than in compression, making it easier to fold the steel on top than it is to pull it apart on the bottom...... in theory.

Yes, I couldn't think of the exact reasoning I was told, but that definitely sparked my memory and remember hearing that same thing. That said, a top truss is strong enough (and more desirable) for what we do.

[fredr1980]

So candidates for the hp44 are as follows

F250 (years?) much beefier housing
F150 78-79
Bronco ?years

I have been doing a bit of searching but I take what I read on the net with a grain of salt. Most guys on here, I'll take them at their word. Dont want ya'll to think Im being lazy.

Would there be room to set the f250 housing up for coils links etc once narrowed?

ed: Found this local. Am I headed the right direction?

http://tampa.craigslist.org/hil/pts/1972008256.html

or this http://tampa.craigslist.org/pnl/pts/1947182467.html looks like it still has the radius arms on it.

F250 (years?) much beefier housing = 77.5 - 79 all have 3"x .5" tubes (pre-77 D44's from F250's are low pinion)

F100/F150 = 71-77, all have 2.75"x.5" tubes (78 & 79 had the wedges cast on and weaker tubes 1/4" IIRC), also IF you are not using anything from the knuckles out (going with chevy flat-tops, small bearing spindles and Ford 5x5.5 rotors instead) then go with a get something that is pre-76 as these had drums and usually go cheaper because of that.

Bronco ?years - none - Early broncos had low pinion D44's and the 78-79 broncos have the same axle as the F150's

There is room for coils on a narrowed F250 D44 as that is the axle that I currently have (narrowed to wagoneer width). I'm using a TNT customs truss with integrated mounts but even then there is still space, the only issue that you will probably run into as I had this issue with mine is that the lower control arm mount on the driver's side is going to be about 1.5-2" into the cast section, I just removed the cast in the area in-order to fit the mount. HTH.

Fred R.

[IndyZJ]

Find out what kind of high steer arm is on the F250 axle. It could be a decent deal for $300 or so if the arm and machining are good. That F150 44 will have cast wedges. IIRC, I gave $200 for a complete stock F250 44.

F250 (years?) much beefier housing = 77.5 - 79 all have 3"x .5" tubes (pre-77 D44's from F250's are low pinion)

F100/F150 = 71-77, all have 2.75"x.5" tubes (78 & 79 had the wedges cast on and weaker tubes 1/4" IIRC), also IF you are not using anything from the knuckles out (going with chevy flat-tops, small bearing spindles and Ford 5x5.5 rotors instead) then go with a get something that is pre-76 as these had drums and usually go cheaper because of that.

Agreed. Also, the F150 spindles, caliper brackets, hubs, and discs will bolt onto the F250 flat-top knuckles to get a 5x5.5 BP. That is what I'm using just because I had the F150 stuff and it means buying fewer parts. Some guys say the Chevy knuckles are stronger, but I've never personally seen anybody have a problem with the Ford stuff on a 44.

[Jeeptech01]

Thanks for all the info guys. I definitely feel a bit more educated now.

[Cody]

I don't have time to read every post ahead of mine, but I'll post my experience.

I ran a hp44 from a 78.5 full size bronco in my old buggy on 37's. Rig probably weighed in the neighborhood of 4000-4500 lbs.

From memory, over about 2 years I broke: (I posted my actual totals a few years ago, but I can't find it--but I'm pretty sure this is right)

18 shafts
12 joints
maybe 30 hubs? Probably more once I switched to Superwinch hubs which 'usually' broke before anything else did. I preferred to swap a hub with a lifetime warrant than a shaft on the trail, + a few hours of my time running around trying to find more once I get home.

Stock 44 shafts aren't up for the task of anything larger than 35's IMO. To echo what Tyler said, full circle clips make a big difference. I used to tack weld the caps on all of my joints instead, but I didn't have to worry about messing up the grease seals or anything since no shaft would last longer than a few weeks. Without a full circle clip or welded caps, a spicer 44 ujoint wouldn't even get me through Pritchett. My problem was almost always the joint failing and taking the shaft out with it, although I did shear 2 outers right at the flange (at the same time even), which was kind of cool I guess.

When I switched to Warn/Yukon alloys hafts (I had Warn outers, Yukon inners) and Bobby Long Ujoints, I never had any other problems. I was also a little less likely to hammer on the expensive shafts since I couldn't afford to replace them, so that might have had something to do with it.

I had a 9" rear, 31 spline stock shafts, in the same rig and never broke those shafts.

I currently run the same style 44 in my ZJ with Warns and CTM's. It was on the rig when I bought it and if I didn't have Warns and CTM's, I don't think the 44 would hold up to my 35's and 5000# + ZJ. With that said, once you spend the coin on a 44 and purchase the upgrades shafts and joints, you could have had a front 60. So I say do it right the first time.

My position has always been the same. If you're wheeling hard enough to break a 30 and you NEED more strength, you need a 60. Otherwise, you're going to spend a lot of $$$ trying to get the 44 to hold up. If you aren't breaking 30 parts but want some of the other advantages of the 44 (bigger ball joints, ring gear, tubes, width etc), then maybe a 44 swap makes sense. Just don't go flogging it thinking that the 44 is some sort of middle ground in strength between a 30 and a 60. Without upgraded shafts, it isn't.

[Jeeptech01]

My position has always been the same. If you're wheeling hard enough to break a 30 and you NEED more strength, you need a 60. Otherwise, you're going to spend a lot of $$$ trying to get the 44 to hold up. If you aren't breaking 30 parts but want some of the other advantages of the 44 (bigger ball joints, ring gear, tubes, width etc), then maybe a 44 swap makes sense. Just don't go flogging it thinking that the 44 is some sort of middle ground in strength between a 30 and a 60. Without upgraded shafts, it isn't.

That is an interesting take on the 30 44 60 question. I honestly figured that the 44 WAS the middleground in strength between the 30 and 60. If I would need to chromo the 44 I cant justify the expense of the 44 over just chromoing (yea new word) the 30 and saving the ground clearance.

[Cody]

That is an interesting take on the 30 44 60 question. I honestly figured that the 44 WAS the middleground in strength between the 30 and 60. If I would need to chromo the 44 I cant justify the expense of the 44 over just chromoing (yea new word) the 30 and saving the ground clearance.

Agreed. I've also seen about 500 broken 44 shafts for every dana 30 ring gear/ball joint/tube failure I've been around. 30 and 44 basically run the same shafts and joints.

[it usually runs fine]

The main reason I chose a 44 was to get selectable hubs so I could run a partially welded front end and still street drive my jeep. The second reason was eliminating the crap unit bearing. The third was whatever stenght gains I might get. The fourth was stronger brakes. The fifth was I hate having to say " Naw man i still have the stock 30 in the front".

[IndyZJ]

That is an interesting take on the 30 44 60 question. I honestly figured that the 44 WAS the middleground in strength between the 30 and 60. If I would need to chromo the 44 I cant justify the expense of the 44 over just chromoing (yea new word) the 30 and saving the ground clearance.

IMO, the biggest advantages of a 44, especially a hp44 over a 30, is a stronger center section and R&P so you don't go pulling a SirFuego all over the place if you upgrade the shafts and joints, beefier Cs and knuckles, selectable hubs, better steering options, and bigger brakes. .

I agree with Cody that in stock form, the overall strength is on par with a 30 due to the shafts and joints. Once you upgrade shafts and joints, the hp44's R&P and bigger carrier come into play.

I'd still limit a chromo'd hp44 at 37s for reliability under a full-bodied rig, but you'd likely never have a problem with it other than maybe an occassional hub depending on brand and driving style. I'd limit a 30 with chromoly shafts to 35s and expect to blow carriers and R&Ps if you're hard on it.

[Jeeptech01]

Yea Im still on the fence about it. I may debate it a bit more in my build as time draws nearer. I dont want to whore up the TOTM anymore with my b/s though so it will be an easier read for those who want to reference it in the future.

[SirFuego]

so you don't go pulling a SirFuego all over the place if you upgrade the shafts and joints, beefier Cs and knuckles, selectable hubs, better steering options, and bigger brakes. .

Heh. Still kept the stock C's, knuckles, brakes, and hubs on mine The only polishing it actually saw was the steering, truss, and shafts.

That said, I actually did a lot of research on HP30's and front Dana 44's before dropping the coin on my RCV's for the D30. Here was my logic for getting RCV shafts.
1) I knew 1 tons were in my future, but the finances weren't there.
2) I had a stock shaft failure take out the internals, so I was a bit biased against the thought of just stocking up on shafts and replacing them as they broke.
3) For every X stock shafts I would break, I figured that I would go through 1 ring and pinion with chromos. Eventually, a stock shaft/joint failure would probably take out a ball joint. I guessed X to be greater than 5. After seeing people around me cringe every time I would crank the wheel to full lock and bump it (without failure), I'd guess X was much greater than 5.
4) Chromos/CTMs were more expensive than RCVs. The extra couple hundred bucks of RCVs vs. chromos/stock ujoints was worth it to not worry about ball joint failure -- and I also figured the chance of needing to use a warranty was less. I figured the transferable warranty on RCVs really upped their resale value too. FWIW, after selling the RCV's, I'm out less than $250 from what I paid for them. I figured I would have lost about that much had I went with normal chromo shafts, too, so the cost is relative...

IMO, the only "problem" with running a polished 30 on 35s is that you NEED to let off the throttle when your front end is bound up or is in the air. On Little Jagger at Harlan, I had both front tires in the air a few times (at least it felt like it -- plus others had their tires in the air at the same spot), but I didn't have the balls to stay in the throttle. I didn't make the obstacle, but I didn't break anything either.

Where I went wrong was that I wasn't saving for 1 tons while I was wheeling my D30. I'm not complaining though because that money went to an engagement ring. After I broke my HP30 a few weeks ago (my front tires were in the air, but didn't let off the throttle), I figured it'd be best to just cut my losses and web wheel while I save for big boy axles.

I am still planning to "wheel" some wheeling events, but my "wheeling" is going to be on the couch while my gas money, registration fees, food money, etc goes into the bank. I might even "break" some stuff to while I'm "wheeling" so I can put more money in the bank while it gets "fixed". Speaking of which, when is GSSE-W? I'd like to "attend" this year -- hopefully even "break" something