stonecrusher steering= bad bumpsteer??

[el burro]

Hey guys I have a b2 using the stonecrusher set up and from what I've read its a wonderful system, but im having bad bump steer coming from the passenger side linkage... Im running soft 170ish pounds per square inch EB coils and a sway bar up front to control the body roll.. The truck has 4 maybe 5 inches of lift. And im using a typical 2 inch drop pitman arm.. Any ideas why im getting bump steer? Im about ready to ditch this setup if I cant get rid of this problem? I can take pics if any one needs to see it. 4X4junkie plz help! Lol

 

[legoms013]

Too much lift and not enough drop to your pitman arm.

You need the linkage to be FLAT, if it isn't you will get bump steer....ask me how I know, I had it bad. Notice the mis-match between lift height and dropped pitman arm height:

This is a universal constant for all types of steering on the TTB RBV steering. It is imperative that your beams and steering linkage pivot points lie on the same plane, or as close to the same plane as possible. This will result in much less bumpsteer, and much better handling characteristics as well as tire wear/TRE wear.

 

[el burro]

gottcha.. So both drivers side linkage and passenger side have to be completely flat? I fear that these coils are so soft that the driver side will be beyond flat and hit the passenger side linkage when the suspension compresses

 

[legoms013]

The more flat the better.

Let me guess, when you hit a bump with the passenger's side tire or a bump that simultaneous causes both sides to compress, the truck "jumps" to the right and you have to steer to the left to correct it?

 

[el burro]

Yeah its does that.. I was looking at the truck and how it sits and the linkage is sometimes flat like when the front end is pointing downward on hills. But when it sits on flat ground it does look like the pitman arm needs to be lowered a inch or so... So im guess when I drive the front end jacks up just a little bit and would pull the steering further away from the pitman arm, maybe that's why I have bump steer?? I would hate to see what my steering would look like after a lower pitman arm on flat ground parked.. I think the two sides of the steering linkage would be dangerously close to hiting eachother.

 

[Hagan]

Can you adjust the steering arm (pitman to tie rod) so other arm is pushed out in front so when the suspension compresses the arms miss each other?

 

[Hagan]

I believe it needs to be level like stock (like my truck). I think you need to put your other drop pitman arm on and fix the reason why the steering arms are contacting each other. Unless you just want to deal with the bump steer?

 

[el burro]

Ya I should experiment with he pitman arm placement.. Im just not sure but I think the pitman arm should be straight with the steering box, facing forward.. Im looking at my steering linkage right now and as it sits my linkage is fairly flat. Not perfect but very close. I could put my extreme drop pitman arm on just to try but those are expensive and I would have to drill in out so I would ruin it, if it doesn't make it any better.. I'll have to see if I can post some pics for u guys..

 

[bobbywalter]

if the drivers link was on top of the bar this would work good

 

[el burro]

see the steering linkage is pretty flat when the truck is sitting on a slope. And other times it seems like it can be flatter. Im sure when im driving and the ttb jacks up the front end a couple inches then i would need and bigger drop pitman arm. But im afraid all other circumstances the passenger side arm would hit the driver side. You can see that the driver side link is already at a downward slope..

View attachment bronc.pdf

 

[el burro]

Just in case you cant open the pdf.....

 

[legoms013]

if the drivers link was on top of the bar this would work good

Think I would have had clearance issues between the pitman arm and the driver's side link if I did that wouldn't I? Maybe I am not thinking of what you are thinking.

 

[bobbywalter]

i would never use a heim like done with this guys setup.


mounting a taper on top and some bending of stock type links nets a livable setup that works killer over stock wheeling and lowers the propensity to lift on the road....but like the setup pictured on my truck here, loses some sai and ackerman so you trade rollie-pollee for push steer....with 300 hp on tap i could make it work beautifully.

but i never perfected it and it had a type of bumpsteer in specific situations....i was running 140 rc coils with air bags to tune street ride though. awesome setup all around

i would put a real tierod on top of this setup with a cut taper seat welded to the top biased to the rear...with a slight bend in the pit to passenger knucle link...

 

[bobbywalter]

http://www.therangerstation.com/forums/showthread.php?p=1030358#post1030358

theres some good stuff here...





with good bends you can work max travel...there is no way to increase up travel over what i had here...

 

[legoms013]

This is still the best lol. But its very hard, and almost impossible to achieve at anything above about 4" max. Can be had with a SJ FA600 or modified SuperRunner. I have almost achieved with with 6" with a modified SuperRunner, and it is lightyears better than the other setups I have run, but it is still isn't perfectly like stock. The best would be a dual swing arm setup like the one pictured in 4x4Junkie's Steering article writeup.

I like BobbyW's setup, cheap and very effective it seems

I believe it needs to be level like stock (like my truck). I think you need to put your other drop pitman arm on and fix the reason why the steering arms are contacting each other. Unless you just want to deal with the bump steer?