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Hydro vs. Crossover, Convince Me of the Way to Go

Bubba Ray Boudreaux

Bubba Ray Boudreaux

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Don't know which way I want to go. I need to know. Don't have any motivation to search, so flood me with info...........

Which system is pound for pound, the better system to use and why?
 
Being that I'm no expert, but from what I've seen with my own eyes, I like the full hydro-steer. Nothing too bind up. But it isn't legal in all states.
 
For you, crossover, probably without hydro assist, because you're going to be driving at high speed. With full hydro there will be no "road" feel and if it fails at high speed, it could be very devistating. Hydro assist may not steer quickly enough for your liking although the 1 1/2" ram looks promising.
 
what are the benefits of hydro assist vs crossover? i thought they dealt with two differenet problems? [ QUOTE ]
Hydro assist may not steer quickly enough for your liking although the 1 1/2" ram looks promising.


[/ QUOTE ] for a daily driven or mostly street driven rig is hydro assist a problem?
 
[ QUOTE ]
what are the benefits of hydro assist vs crossover? i thought they dealt with two differenet problems? [ QUOTE ]
Hydro assist may not steer quickly enough for your liking although the 1 1/2" ram looks promising.


[/ QUOTE ] for a daily driven or mostly street driven rig is hydro assist a problem?

[/ QUOTE ]

Hydro assist helps you steer with big tires, crossover helps you steer...well, period. /forums/images/graemlins/rotfl.gif

For a DD rig I'd say the 1 1/2" ram would be ok, but for desert racing at 80+ MPH I'd say it's unnecessary, and undesireable. When I was going faster than 10 MPH I never had a problem steering. The ram is there to help me steer when I'm stopped more than anything else.
 
a manual gear box would work at 80+ mph, speed makes it easier to steer. I'd agree with tim, crossover wihttout or with small quick ram.
 
so crossover would benefit both slow and normal onroad speed driving? no drawbacks? would a 1-1/2" hydro assist setup be highway safe at 65 or 75 mph? or would just crossover be better. what size tires would hydro assist really start to benefit /forums/images/graemlins/dunno.gif
 
[ QUOTE ]
so crossover would benefit both slow and normal onroad speed driving? no drawbacks? would a 1-1/2" hydro assist setup be highway safe at 65 or 75 mph? or would just crossover be better. what size tires would hydro assist really start to benefit /forums/images/graemlins/dunno.gif

[/ QUOTE ]

No drawbacks to crossover except increased stress on the frame laterally. Make sure you have the bolt on brace if you do it.

1 1/2" hydro is perfectly safe on the highway.

The width is what makes hydro desirable. I've got 16" wide tires, I'm 5'4"/133#, and lockers in both ends....I really love my hydro! /forums/images/graemlins/rotfl.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
 
If it EVER sees street use for more than a "quick test run" do not go full hydro. I think x-over and ram assist is the way to go no matter what rig it is other than comp. Fred (FWP) has it and says that the steering is only slow when doing fast doughnuts. I am going with a 1.5" ram cause mine is still a DD.
 
From what I understand and know (which probably isn't a whole lot) it is not a good idea to do hydro without crossover. the way i see it; you are wheelin and come across a little washout in a road, you cross it diagonally. when you cross it a stock steering setup will turn your tire as you go down. can you imagine a ram "trying" to hold the tire straight. something will bind up and i think something will break.
 
[ QUOTE ]
so crossover would benefit both slow and normal onroad speed driving? no drawbacks? would a 1-1/2" hydro assist setup be highway safe at 65 or 75 mph?

[/ QUOTE ]

my truck sees more highway use than it really should (no trailer) and can do 70, though i like to keep it 60-65 and i have no problems w/ the assist. and i have the 2" ram
 
[ QUOTE ]

No drawbacks to crossover except increased stress on the frame laterally. Make sure you have the bolt on brace if you do it.


[/ QUOTE ]
Not quite correct. Cross over will also give you bump steer. The more angle in the drag link (straight line from pivot to pivot), the more bump steer you will have. But without hydro assist to take the stress off the box, I agree on the need for the brace at a minimum.

Cross over is generally only going to help when dealing with steering while crossed up. The stock drag link it to short for the amount of axle movement we tend to want. So, when the driver's tire droops way down, the drag link gets more and more vertical. This results in less steering range (angle side to side), more difficulty turning the wheel, and more stress throughout the system (including breaking the box off the frame). Cross over corrects this by making a much longer drag link so that for the same amount of droop, you don't pick up much angle. But you do get some angle, even on straight compression and rebound (such as crossing a dip in the road) which is exactly what leads to "bump steer". There is no change in mechanical (or otherwise) advantage, so the ability to steer is not changed except in the crossed-up scenario.

Hydro Assist is completely different. It makes it possible to steer when you have large tires (especially with front locker) without needing arms like Popeye. That's it, it's just more power for your power steering. Rate of steer is a function of fluid flow, ram travel, and ram diameter (basically, ram volume). Power and rate are inversely proportional, so more power means slower steering, all things other than the ram remaining the same.

The only connection between the two is that IF you have Hydro Assist, THEN you better have cross over steering first. This is because traditional steering limits the range (angle) of steering when the drivers tire is compressed/drooped. But the ram, mounted to the axle, could not care less about the range of motion allowed by the draglink/box, so it will try to keep pushing till it reaches its normal limits way beyond what the angled drag link will allow. The relief valve will keep it somewhat in check for a while, but eventually something is going to give, probably the frame…
 
I have heard you refer to the relief valve on a few occasions. What exactly does it do? Is it in the stock box and still usable when ported for a ram? I am assuming it is kinda like a contained pop-off (blow-by) valve in an air compressor system.
 
uhhh... not sure I understand the question. What you want is BOTH.

j
 
It's a pressure bypass valve inside the pump. When pressures get to a preset max, it recalculates to keep the pressure in check.

Oh, and it's a balanced system. The high pressure side of steering box and ram are both at the same pressure, as is the low side. The bump-steer binding does not happen (much) because the fluid can flow and let the system stabilize. However, it does act like a damper to some extent so some there is some stress as it equalizes.
 
[ QUOTE ]
No drawbacks to crossover except increased stress on the frame laterally.

[/ QUOTE ]

Tim, is crossover steering a problem on unlifted trucks???

The gentleman asking the question doesn't have any specs listed of his rig. I thought engine crossmember to draglink clearance was an issue under 4" of lift. I could be wrong.........please correct me as I have never attempted crossover steering.
 
[ QUOTE ]
uhhh... not sure I understand the question. What you want is BOTH.

j

[/ QUOTE ]
IMO, not really. Only a rock crawler with big tires and a front locker really *needs* both. If you run whoops, washes, sand, etc. with a prerunnerish truck, then you could easily forgo the assist, which is really only needed for turning in place without rolling. I run 42s and a front locker on my truggy and run rocks, I need both. My 1 ton K5 runs 35" ATs with a front locker and has no need of hydro-assist at all. Normal "trail runners" don't really need assist either since they can usually turn while rolling. Sure, it some cases on most any truck it would be "nice to have", but it really does not justify the cost and added complexity (plus points of failure) to add hydro-assist to most of them…
 
that is why I said "want"... and not "need". /forums/images/graemlins/thumb.gif i have a detroit in the front, and tiny lil 39.5s... Im sure glad I have assist! /forums/images/graemlins/laugh.gif

j
 
You must have a lift. I have heard that it can be done with 2.5" of lift and up. I have 4.5" total front lift and I have probably tagged the crossmember a couple times with a bent draglink. Some grinding would probably make me clear without problems. I have never felt the hits or had them stop my steering. It is all individual to the setup though.

A guy I know runs 4" lift with a straight draglink and not hits. His axle is moved 1" forward though.

A sway bar is out of the question with crossover.

Each crossover system on peoples trucks is different. With the different combonations pitman arms, lift height, location of bend in the draglink, steering arm spacers, spring thickness, flex, etc there are alot of variables. This is especially true on a peice together system if you mix and match components and homebuild things.

Harley
 
Cross member clearance is pretty much always an issue for any reasonable amount of lift, assuming you have any up travel. But that can be corrected with a bent drag link or new/modified crossmember.
 
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