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crossover and bumpsteer

Steering is only concerned with the attachment points. If point A and point B are seperated by 3 vertical inches and you replace a straight rod with a bent rod, there are still 3" of vertical separation.

Only way to improve steering geometry is to reduce the amount of vertical seperation
 
Dont do a track/panhard bar. Its counter productive to the way the left spring suspension wants to work...

Make sure your spring bushings are good, better yet replace them with shouldered poly to eliminate twist. Also going to a shorter, or crosstied shackle can make a big difference.
 
miniwally said:
A bent drag link is only bent to provide clearance around some component, a bent or straight drag link are no different as far as the conversation about bump-steer is concerned.
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I understand that part of it. I guess the original quote was a little confusing on the wording. What would cause bump steer to be worse on some vehicles? I have new leaf springs with poly bushings, all new components on crossover, and ORD steering box brace. Yet, I still have a good bit of bump steer while driving. It doesn't really bother me and I always thought it was normal. This thread has me wondering why some have none/minimal bumpsteer. Just my curious mind working I guess
 
I think it might be the components themselves. Take an extreme example of worn stuff. On Horton the front upper shackle hanger moves the entire frame. It didn't used too but to actually twists the metal. The bushing twists too. Couple those two together and it steers awful.

I have the exact same setup as alot of guys on here who steer way better than I do.

So I think alot of it can be overall condition of the truck. And sometimes you can't really see the problems
 
I notice bumpsteer on my setup. It's not extreme, but I never noticed anything before. Before = stiff springs, not crossover, factory steering shaft. Now = ORD springs, crossover, Borgeson U-joint steering shaft. Pretty sure I'd stick with rag joint if I had it to do over.

I also noticed my springs and shackles were torqued very loose. I put them up to 50 ft-lbs and have not really had a test drive since. That might make a difference.
 
Stomis said:
Dont do a track/panhard bar. Its counter productive to the way the left spring suspension wants to work...

Make sure your spring bushings are good, better yet replace them with shouldered poly to eliminate twist. Also going to a shorter, or crosstied shackle can make a big difference.
Click to expand...

Everything is in good/new shape and nice and tight. I really dont see how a track bar will hurt my setup, it is already flexier than I want (40s with around 4 inches of lift). If I could get the draglink closer to flat it would cure the issue, but it would have to come up 1.5-2".

Another thing that I am noticing is that these shocks are pretty soft, and that a little stiffer would slow the suspension down to where the bumpsteer would feel much less
 
A track bar will hurt any leaf setup. Its just counter productive to the way a leaf spring suspension wants to cycle. Now if you feel you can live with that and want to spend the time and money building a panhard to fix it than do it, but just like putting hydro over death wobble its just a bandaid.
 
One thing to check with a factory type steering system is that the swaybar isn't messing with you. If you're running steering correction pieces (like a drop pitman arm) you need disconnects for the swaybar to let it pivot freely and not bind up the axle, or rather not force the axle to move in an arc different from the steering linkage. My burb with 3" TCIs and a drop pitman was amazingly nice to drive, one of the best non-linked steering systems we've had. It had disconnects for sure.

With crossover, you do have bumpsteer. Period. You may not feel it due to a bunch of other factors but it's there. If the axle moves up the steering arm gets closer to the pitman arm and something has to move, either the steering wheel whips a bit or the tires turn. The way a panhard bar makes this disappear is not that it prevents the axle from moving side to side, it's that it FORCES the axle to move side to side in the same arc as the draglink. Just like a panhard/draglink system does on a linked up front suspension. The problem is that leaves only like to move side to side a little and the panhard can force them to move a lot so it's generally hard on bushings and even on frame mounts. But they do drive nice. I did the leaves with panhard for a while on my way to coilovers.

Ways to minimize bumpsteer with leaves? Make the draglink as flat as possible or make the suspension move less. It's pretty hard to tune much on the draglink angle and nobody wants the suspension to have less travel so it's a bit of a dead end. But in general it's not that bad and the fact that it actually steers offroad is typically worth it. With a tall truck (8" lift +) we consider crossover a must even on the street. With a short truck and mostly street driving we often work with the factory system. Incidently this is also part of the reason we don't get super excited about building extreme long travel leaf spring front suspensions. If you're going to go fast enough to use the travel you're going to fight the steering.
 
Stephen said:
With crossover, you do have bumpsteer. Period. You may not feel it due to a bunch of other factors but it's there. If the axle moves up the steering arm gets closer to the pitman arm and something has to move, either the steering wheel whips a bit or the tires turn.
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See, even Stephen agrees with me, so I must be right.
 
So I will share what I figured out with this, and might also be why (other than the human factor) some feel they have bumpsteer, while others claim none. I noticed that a firm grip on the steering wheel would all but cover up felt bumpsteer, while a loose grip or no grip would let the wheel wiggle all over the place.

When I adjusted this steering gear on the bench before install, I just tightened it up to no slack, but no over center preload. I wondered if setting the over center preload by the book, would act like having a firm grip on the wheel, and so I adjusted it up. I feel almost NO bumpsteer, where before it was enough that it was really anoying. I do understand that now the front tires are probably steering slightly on bumps instead of the steering wheel wiggling, but it is so much nicer to drive.
 
Finally took a good test drive after ensuring good tight bushings. Everything is new and tight on this truck. There's a section near here with a bunch of rolling hill kinds of things where the speed limit is around 45. I found the level of bumpsteer a bit disconcerting as the weight on the suspension went up and down and the thing steered left and right. It's not hazardous, but it gets my attention compared to just blasting through in my Jeep or my wife's car.

20160320_093850.jpg
 
black dawg said:
So I will share what I figured out with this, and might also be why (other than the human factor) some feel they have bumpsteer, while others claim none. I noticed that a firm grip on the steering wheel would all but cover up felt bumpsteer, while a loose grip or no grip would let the wheel wiggle all over the place.

When I adjusted this steering gear on the bench before install, I just tightened it up to no slack, but no over center preload. I wondered if setting the over center preload by the book, would act like having a firm grip on the wheel, and so I adjusted it up. I feel almost NO bumpsteer, where before it was enough that it was really anoying. I do understand that now the front tires are probably steering slightly on bumps instead of the steering wheel wiggling, but it is so much nicer to drive.
Click to expand...

You may have a loose steering gear box. This can cause a small amount of bump steer. A steering wheel that is constantly getting off-center is a sign of a loose steering gear box.
 
Here's mu setup, I reused the old TRE's due to them being new a couple years ago. I run a Superlift pitman arm and unknown brand steering arm for my 60. But I went w/ the inserts and jam nuts from Ruff Stuff for crossover. When I did ram assist I used a guy of Ebay his name is I believe Greatautodeals for TRE's, jam nuts, & inserts, great stuff and hasn't failed me yet....



 
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