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I have always operated on the theory that the cylinder will be fine without any steering stops, and the greatly reduced stress on the knuckles is worth the small potential added stress on the cylinder. But you raise a good point.
I can see how just the right hard roll at full lock could stress the cylinder. But at that point, you are getting into fastener and rod end failure territory too. Even the tire should deform some before shaft of the cylinder sees much force. And in my case, my non-indexed cylinder will slip in its clamps first... which is maybe the only side benefit to the old psc design. So who knows what percent of the time it would actually cause a cylinder failure.
I came across this post randomly that confirms your theory, fuego.
http://pirate4x4.com/forum/showpost....6&postcount=43
Okay lets us take this in a new direction. When operating a skid steer, loader, or dozer, there are no stops other then max extension or two much weight for the ram to operate. Either of these things will not blow the rams.
I deal with hydralic cylinders all the time. Most cylinders limits are made by the internal measurments. It will bottom out in the cylinder shell and top out in the cylinder cap. Some do have stops built into the ram/piston assembly, but in the end they will still stop by the shell.
Just like slim616 said....Take a forklift. There is no steering stops and they turn as far as the cylinder length is.
My feelings, Steering stops arent very inportant.
Rick
Jared, Limit it with the ram.
If you manage to bend a ram, you probably did something cool.
I agree any position you put the ram it should be able to hold up. The group i off road with runs full hydro on almost every rig, and all of them have the ram limiting. I have never seen a ram break or anything under any sort of pressure situation. Actually the only time I ever seen a ram break is with a drunk dude at the wheel ramming a ledge with it.
I'm trying to decide what to do for steering. Since this is only about full hydro steering, let's not worry about hydro assist for this question...
Single ended ram vs double ended ram.
Pros/Cons of both. I know single ended isn't as ideal as double ended, but is traditionally cheaper. Trying to get an idea if I'd be OK with the cost and performance tradeoffs of a single ended ram setup. I know I briefly talked about this with Trey a couple weeks ago, but just looking for any more input I could get.
Last edited by SirFuego; 08-18-2010 at 02:41 PM.
single ended ram is ~1/5 price of double ended and mounting is a little simpler..
single ended isn't balanced.. Your steering will operate at different speeds turning left or right.. its noticable but negligable IMO..
Its harder to use all hi-steer parts with a single ended ram unless you get real creative and feel like fabbing hi steer arms or going behind the axle with either the tie rod or the ram.. This equates to me building a new tierod about once a year. I have my SE ram operating the hi steer arm on the pass knuckle, and the tie rod in the factory holes (drilled to 3/4 for heims of course)
Mounting a double ended cylinder is a little more fab intensive but you can get some awesome ground clearance around the front diff. its real popular for guys to incorporate a front axle truss into mounting the cylinder and then triangulated uppers have a nice home..
with a double ended cylinder the fluid in the resevoir of the pump will vary depending on which direction you are turning. I run a stock pump and resevoir, when i get the rig really steep (up or down) and turn lock to lock I lose some fluid and the pump will start whining. refill the res and its good to go... other than that im pretty happy with the stock pump..
my .02 FWIW
Also a balanced cylinder is more likely to play nice with a load reactive orbital. This means that you may actually experience some return to center if you have your caster set within an acceptable range.
Not having run an unbalanced cylinder (other than with assist), I can't truly compare, but I will say that my balanced cylinder (DE) is extremely predictable both crawling and at speed. At 65+ there is no noticeable wander, no tendency to overcorrect, and spools excluded, is almost as easy to drive as my Titan.
That said, I do like the fact that a single end setup has a tie rod as somewhat of a fail safe... not that either cylinder should be mounted where it can tear off, but stuff happens. Trey has a point about the cost, although I think it's a bit exaggerated especially if you piece a DE setup together yourself. This cylinder is a pretty good deal. But, if you are comparing to a PSC kit, then yes, that can get expensive... but what you're buying there is the convenience of not having to do any hunting around or math to match your orbital and cylinder to get the # turns lock to lock that you want...
http://baileynet.com/index.php?dnfwd...ileyno=218-832
looks like i did exaggerate the cost difference, when i bought my cylinder it was 59.99 and free shipping. surplus center is pretty expensive on shipping.
Jared,
I'll let you know in about a week. I'm converting to Single ended hydro right now. If it works out, you can drive it, then drive Ryan's or Dom's. they both have DE rams.
ZJeepin, what size ram do you run? What displ. orbital?
I have a 2" ram on right now for hydro assist. (Inverted T Steering) My plan is to lose the drag link, replace the steering box with an orbital (literally mount the orbital where the steering box was) and hook up the lines. My failsafe is that I can stick the box and drag link back on if something fails in the system. My steering box was limiting the flow to the big ram, making it slow at higher speeds. I'm hoping this fixes the issue.
im running the ram i linked to in my last post..
its a 2.5x8 with 1.125 shaft. my orbital is off a tractor and is 10.2 cu/in. I have a little over 3 turns lock to lock
How do you like the strength of that pump?
I also swapped the stock pulley onto the unit in order to keep the same length serpentine. The pump actually came with a smaller pulley, did yours?
From my experience and most likely becuase I never ran a cooler, it seemed under powered. I had that same kit. Especially for the weight of the ZJ. It really didn't meet my expectations as far as turning power. ( Now that i think about it some more. Whe I did the engine swap on my scram I noticed that the pulley wasn't fitting onto the new power steering pump I purchased. I had to go to a yard and get a new unit for the pulley and as a core. I wonder if my pulley was slipping on the PSC pump? Keep an eye on that after time.) I wasn't able to pivot and push with the wheels like I wanted to. Maybe the double eneded ram I purchased was smaller. However it was really predictable at speed and I felt comfortable doing 75+ on the highway or in the wash.
Dont you think heating up that shitty collar may have weakend it some, or is this the norm? I ran mine with the stock ZJ steering linkage and didn't weld the collar. No issues for years. if anything just run a nice tac where the small bolt tightens the collar. ( Now that I look at your pics again it seems that you had to drill it out. I see why you did it. When I bought mine it matched up to the stock size.)
Last edited by Tommy; 08-18-2010 at 05:56 PM.
http://www.trail-gear.com/toyota-ful...c-steering-kit
BAM! Good price and comes with everything you would need. The pump even bolts right up the the stock location. This is the exact setup I use and it has been great so far! I can get you even better pricing too, if you're interested Jared, just PM me.
yes, due to the shaft only displacing fluid on one side of the cylinder the amount of fluid in the res will change as you steer. On mine it gets really full when i steer all the way driver and gets low when i steer hard passenger. Its also why you're steering will react at a different rate depending on which direction you turn.
It s all about the plunger surface area. On one side the rod takes up space fluid would otherwise. And surface area x pressure = force.
I was over SB406's garage to pick up some stuff last night and picked his brain on some full hydro stuff, which prompted me to do some more research when I got home.
1) From what I've been reading, load reactive orbitals (basically all of the major offroad hydro steering companies sell only load reactive orbitals) only really "return to center" when you are running positive caster. For those running load reactive orbitals, do you find it actually returning to center? Did you rotate your inner C's for a positive caster angle?
2) Since load reactive simply allows external forces to act on the orbital, do you ever find it ripping the steering wheel out of your hand?
3) For those running non-reactive, I've been reading that it can get squirrely at "high speeds". What speeds do you find things to get squirrely at?
4) How do you like a non-load reactive orbital in the rocks? I've been reading that a lot of dedicated crawlers actually prefer this because it requires less effort to keep the tires on the line you want.
5) Lock-to-lock. Are you happy with the number of lock to lock rotations you have?
6) Is anyone running a smaller pulley to increase pump output at low RPMs? Has anyone done the "West Texas Offroad" pump mod?
7) Where can I find specs on the stock TC pump?
Looking at what I want to do with my rig, I think I'm actually leaning towards a non-load reactive orbital and I'm undecided on how many turns lock-to-lock I would like to target, but I'm thinking I'd prefer it on the lower end -- like 2.5-3 turns.
Last edited by SirFuego; 08-24-2010 at 04:11 PM.
I went for stock when I calculated lock to lock on my car (edited) - 2.5, and if I were to build again I'd do the same.
I "think" I'm running a load reactive orbital, but I doubt I have positive caster. I don't recall if it returns to center, but I can feel "just enough" in the steering wheel to feel the trail a bit.
Last edited by OverkillZJ; 08-24-2010 at 04:35 PM.
Last edited by SirFuego; 08-24-2010 at 04:19 PM.
Stock is 3.75 IIRC
Matt, all of PSC's valves are load reactive if that's what you have...
You're right - I based it off of my stock Corolla, I remember now! I remember always liking how much less I had to turn the wheel in the car and the feel of it, so I based the math on the bore size off of 2.5. Anyway, I really like 2.5, I think it really worked out to like 2.75 or something, but it's enough to not make jerky movements, and not too much to get a work out with maneuvering.
EDIT: It is PSC, so load reactive. And for sale shortly, beginning to take it apart this weekend.
To keep the conversation going on some of Jared's questions...
I'm not sure why you would want to run a non load reactive valve with a double rod cylinder (technically that's what they are called - as opposed to double ended ram like everyone says) for anything besides the fear of kickback. They can actually break your hand in certain situations if the wheel kicks back quick enough... there have been accounts of it happening on pirate and there are even some youtube videos of it happening, although I've never seen it personally. Sean Stapley (POS/Station) who used to be big in the full hydro scene, had a line on an anti-kickback valve that can prevent this from occurring, although I'm not sure how much they cost or even how complicated they were... it may be just a simple hydraulic check valve that is obtainable anywhere...
Your point about following a line through the rocks being easier with a non-load reactive valve, however, is valid. I think it probably would be better in that situation. But, I have grown to appreciate how my load reactive valve gives some feedback in the rocks, because if I really shouldn't be taking a line (i.e. wedging a tire directly into a rock in a way it shouldn't be), it will push off and force me to fight it to take the line that's harder on parts, knuckles especially. But if you have $300 a piece cast chromoly knuckles, then it might be less of a concern...
You are prone to burn up pumps from excessive RPM, including TC style pumps like ZJs have, if you try to hot rod them and run a cheater pulley.
I did the west texas mod back in the day and noticed little to no difference. The P style pump I run now is by far the best I have run with any setup- full, assist, or non hydro.
Last edited by ATL ZJ; 08-24-2010 at 04:47 PM.
Looks like I missed this:
www.pirate4x4.com/tech/billavista/PR-Hydro_Steering/TC%20Pumps%201.jpg
2.4-2.8 GPM, 1350-1450 PSI.
Last edited by SirFuego; 08-24-2010 at 04:52 PM.
I had to remove the http for it to work, so in case anybody else has the same problem... www.pirate4x4.com/tech/billavista/PR-Hydro_Steering/TC Pumps 1.jpg
With a stock size pulley, I blew up 2 PSC pumps. Both situations were at almost full throttle, and they repaired them; but it was a true pain losing steering with 42's. I think it was a 1405 pump, they seemed to just state that it happens if you're at a high enough RPM and something occurs to give the pump enough feedback. I can't remember the technical details.
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