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Discussion Starter · #1 ·
Background: I currently have a single ended 1.5 x 8" ram for hydro assist. When the pump is working properly, the speed is just fine. But I dislike how fast seals wear out and how easy it is to bend the small shaft and how the speed is different depending on which direction I am turning, due to the single ended ram setup.

What I want to do is run a double ended ram in place of my tie rod but still only run an assist setup since this is a daily driver. I have searched and read about this being done but my question does not ask if it can be done, it has to do with the fluid volume and ram speed.

If my calculations are correct, it takes approx. 5.551 cubic inches of fluid to extend my ram 1", less fluid to retract due to the ram rod being in there. The ram I want to use is a 2.25" bore but with an 1.5" shaft. Now finding the volume of the bore and subracting the volume of the shaft it should take approx. 6.939 cubic inches of fluid to move the ram either direction 1". So the total difference between the current ram and the new ram would only be 1.387 cubic inches of fluid.

At the time of this swap I will also be swapping from a single stock pump to dual pumps, one running the hydroboost brakes and one running the hydro assist steering, the steering pump being the HOWE P-Pump. The stock pump, as far as I can tell, is rated at around 1000 psi and 2-2.5 gpm. The HOWE pump is 1600 psi and 4.5 gpm.

So, with the minor increase in cylinder volume, and the rather large increase in fluid, I should not have any steering speed problems correct? I've always been told to stay under 1.75" bore for on road speed but that was for single ended rams withs mall diameter shafts, not this monster.

Anyway, any tips or pointers on this would be great regarding volume, speed, pump selection, and general use of the double ended ram vs. single ended ram. And Station, any advice you can add would be greatly appreciated since you are the resident expert. Thanks in advance:D
 

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your scrwed just junk the mobil home and build the big tube buggy:p

you still want that 14bolt or what? i can possably drop it off on my way to put up or shut up the first weekend in jan;)

jeff
 

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Discussion Starter · #4 ·
Yeah I do and that will work fine... Is that what Chaz is going to be running in in Jan? I'm going to go watch him in the buggy.

Anyway, I am building a buggy:flipoff2:
 

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"What I want to do is run a double ended ram in place of my tie rod but still only run an assist setup since this is a daily driver."

I see a problem with this as he is talking about using it in an 'assist mode' and replacing his tierod. unless his dragling connect directly to the knuckle won't work, and even if it did marginally, wouldn't you be asking for it bind?
 

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Discussion Starter · #7 ·
Why would it bind? My drag link ties to the top of my pass. knuckle via steering arm (d60).

The ram will act just like a tie rod since the shaft is solid throughout it then 2 short tie rods between the ends of the ram and the knuckles.

Just like this:



But with a drag link.
 

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Maybe I'm missing something but, I don't understand how an assist system can be slower in one direction than in the other? If your cylinder is not allowing you to turn the wheel as fast one direction then you need to port your stock pump. You need more volume if that is the case. An assist system still has to be the same number of turns both ways since it goes through the stock box. I don't see the double ended cylinder as a necessary fix. I am think all you need to do is port your pump in order to get the flow that it requires. I have been around quite a few assist systems and have not noticed one of them being "slower" in one direction than the other. I run full hydro and that is my problem but, that is not the set up you run.
 

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Discussion Starter · #9 · (Edited)
Well it's not neccesarily slower, it's weaker... There is less fluid volume on the shaft side so it has less power. The way I figure it is if my current ram takes 5.551 cubic inches of fluid on the non-shaft side and that produces plenty of steering power, then a double ended ram that takes 6.939 cubic inches will have even more power and it will be even on both sides.

An example is, when I'm aired down and sitting parked, I can turn my wheels left easily to full lock, but I cannot turn right as easily, takes considerably more force.
 

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HHMMMMM....interesting.

how about this, have your drag link go from the pitman arm to the pass. side knuckle. then have the double ended ram behind the axle forming the tierod/ram?

steelman
 

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Discussion Starter · #11 ·
steelman said:
HHMMMMM....interesting.

how about this, have your drag link go from the pitman arm to the pass. side knuckle. then have the double ended ram behind the axle forming the tierod/ram?

steelman
Yeah thats exactly what I am planning on doing as long as I have oil pan clearance. It's either going to be high steer behind or infront if I don't have clearance...
 

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Discussion Starter · #12 ·
Well how about this question. The ram I have found is rather cheap and brand new. Only downside is that it's a 10" stroke. Wouldn't it be just fine if I put stops either on the inside or the the outside on the shafts and the correct locations so the ram hits it's stops as the knuckles hit theres?
 

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Sounds like a plan. But would it be tight enough for DD or would it wobble around?

Did you ever get the 41's on the truck? Pics?
 

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Discussion Starter · #14 ·
Why would it be any more loose than a normal tie rod? I run Heims on the end of my tie rod currently, so this would just be 2 more heims than I currently have but as long as they are replaced as they wear there shouldn't be any play at all... The ram is one solid shaft so it should be plenty ridgid...

You mean the 44.5's? Nope, waiting on funds to order the rims from John. I keep having to fix things like steering and such and it keeps eating up my money...
 

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As an assist, you will be asking the double ram to work in perfect unison(sp?) with you mechanical steering gear. That's where I see the problems. I can see where you the box will be fighting the ram at times. Could be wrong, I'm no expert, but at the point you take the tie rod out you have taken the leap of faith toward full hydro, why not do it all the way? I think double ended ram set-ups in an assist mode have been designed to work with a tie-rod not replace it.

I think you will have a very hard time finding a ram properly sized to the flow rate of your pump to make it all work smoothly. Good luck on it.
 

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Discussion Starter · #16 ·
Yeah, once I get it I was going to check it out and see if what can be done. If it is welded on each end and not "take apart able" I will probably see if I can chuck it in a lathe and use a parting tool to cut one end off, then cut 2" or so off, then weld the end back on... If thats no possible then I'll just figure out some stops that will mount to the shaft on the outside on each end. What I was thinking was cutting the ends of the shaft off so thre won't be a ton of extra shaft sticking out each side.
 

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I look forward to hearing and seeing how successful you are in setting it up the way willyswanter described. I totally understand how hydro assist works. Of course the double-ended cylinder is one solid rod. I doubt you guys plan on running it without fluid, so in that case hydraulics come into play. My point is that when a cylinder that is too large is used as an assist it makes the steering slow and sluggish. Mismatched shiat performs like shiat. Sounds like you guys are gonna pick up the cheapest shiat you find and throw it on there. Might work, might not, but... once he butchers his tie-rod, does all the fab and realizes his DD rig drives like shiat, he'll start to really think about why? Maybe he'll luck out, after all, the blind squirrels eats too.... Anyway you guys sound like you are the experts on the subject, I was trying to help. Sorry to interfere. I'd like to hear from someone who really knows like Matt or Sean for some clarity. I would like to learn something from this. Good luck! Peace Out!
 

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Discussion Starter · #18 · (Edited)
So did you bother reading my first post where I calculated the volume of fluid needed? With the larger shaft inside the larger bore it only requires a fraction more fluid than my current 1.5" system uses... 1.387 cubic inches to be exact. The total volume ofthe larger ram is only 6.939 where as a 1.75" ram, something used commonly on assist, is 7.56 cubic inches. It doesn't matter how big the ram is, only the volume of fluid needed. I have a feelign that you are thinking of just how large the bore is, at 2.25". But you have to remember, there is a 1.5" shaft going through the whole thing taking up space.

And about your butchering of my tie rod, I'm not going to, I'm keeping it as a spare incase anything does go wrong ever on the trail. If I bend the ram or blow a heim, I can slap the old tie rod back on, I'm going to use quick connects on the ram.

I look forward to hearing from Matt or Sean as well, I currently run Matt's full setup on my truck and I have talked with him numerous times, not about this particular setup though.
 

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I'm running the 2.25" ram 1.5" rod 8" stroke on my full hydro set-up. I got rid of my tie-rod. I know all of the volume calculations you are working with, so that's not a concern. The question is do you think your ram is going to be assisting the steering box or just taking it for a ride? Is the ram assist or primary? Who cares I guess, as long as it works.

Seems like you have all of the bases covered, please report to the list how it works out. Thanks for helping me through understanding the geniuos of your design.
 

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Discussion Starter · #20 ·
Well let me ask you, or anyone else, this: You mention which becomes primary, the ram or the box... Well, in a regular assist system, the ram is stronger than the box. But usually is slower than the box, well, all the systems I have seen have been. With the new setup I plan on, the ram will be stronger than the box, and slower than the box... What would the difference be?

Lets get back to the whole reason I posted this, I do not like the different speed and pressures when turning one way or the other. When I turn left, I have alot of steering power but it's slower... When I turn right it's faster but less power... I want something even both ways, thus the reason for the double ended ram.

If there is a huge problem with the actual setup, ram size and selection aside, just the basic setup of using a double ended ram in place of the tierod on a ram assist setup, what is it? Or if there is not one...
 
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