Bump steer for a year

[subversive]

I installed a 2.5" OME lift kit from DPG Offroad a year ago along with new wheels and tires. I've been struggling with bump steer ever since. I've taken it to 3 shops now to try and get some help. The last shop I took it to was a 4x4 shop. The guys there said that all the steering components looked good and that all they could do was an alignment. I agreed and when I got it back it was exactly the same.

Here are the numbers from my recent alignment:
Caster: L 6.01 R 6.14
Camber: L -.49 R -.87
Toe: L .06 R .06

My tires are 255/70R-16 on 16x8 Black Rock 997s.

Here's a link to a couple of pictures of my track bar and drag link angles:
http://imgur.com/a/wcI9f

Thanks for taking a look. I'm out of ideas and would definitely appreciate some input.

 

[x-jay vision]

The problem is that your track bar is substantially shorter than your drag link. Its not just about the angle, but the length too.

 

[subversive]

How should I properly correct that problem? I'd imagine it's not as simple as extending the track bar and making it fit.

 

[subversive]

I just went out and measured. My track bar is 5 inches shorter than my drag link.

 

[Tim_MN]

1) Is the front front axle centered under the Jeep ?

2) How much toe-in is there ? You should have about 1/8 inch toe-in, IDK what the comes out to in degrees.

The problem is that your track bar is substantially shorter than your drag link. Its not just about the angle, but the length too.

Sounds like BS to me. I have had a stock drag link at 2",3.5", and 5.5' of lift, and no bump steer ever.

 

[subversive]

Just got done doing some measurements. The toe is perfect and the axle is only about 1/2" farther over on the passenger side.

I've heard about the length of the track bar and drag link in other forums before, still not even sure how I would go about achieving that without totally relocating my track bar.

 

[mtbxj87]

I would think if length of the track to drag link was different, every stock jeep out there would have the same bump steer.

 

[x-jay vision]

As the angle between parallel and the track bar increases (lift) the difference in length matters more. It's basic trig. In terms of angle of steering wheel rotation, how much bumpsteer are we talking about, say, on a bridge abutment?

 

[subversive]

Minor bumps or troughs in the road give me somewhere around 15 degrees if I hit them just right. I was driving down a country road that recently had potholes filled in and each new patch of asphalt that I hit would jolt my wheels. If I hit a good bump or like your example, a bridge abutment, I get around 30 degrees of movement and even vibration that reminds me of death wobble, but it quickly corrects itself.

 

[x-jay vision]

The bumpsteer doesn't sound too bad, the wobble however sounds like something else. I would start with track bar bushing and ball joints. Any play in those warrants replacement.

 

[subversive]

For comparison I can drive my wife's civic down the same country road going 50 with no problem. In my XJ I have to drive 30 and constantly dodge any uneven pavement. That's why the bump steer is my primary concern right now.

I recently got a new job which is about a 30 mile drive. At this point, It's either fix the bump steer or get a new car. But who would want to buy an XJ that can't handle some wimpy bumps in the road? I want to keep my XJ because it's my tank, but since I'm going to have a decent commute, I'd like it to drive straight.

I've checked all my steering components to see if they needed to be replaced and I've taken it to three different shops, one 4x4 shop, one specialty auto shop, and one ma and pop shop. They all confirmed that my components are at the very least in good repair, yet they all have a different excuse for the bump steer.

Ma and pa recommended a drop pitman arm, which I knew was incorrect.

The specialty shop pretty much said, that's what ya get when you lift a vehicle.

4x4 said bump steer is common with jeeps in general, but I should get a beefier stabilizer.

The way I see it, there are several jeeps out there with bigger lifts and no issues. There must be a solution to this that I'm just not seeing.

 

[831_xj]

Go take a look at your ball joints perhaps. How about a pic straight on of your front end even

 

[Devilfrog]

No matter what you do, there will always be some bumpsteer associated with the stock Jeep steering arrangement (or with just about any solid axle arangement). The entire axle is moving independently of the frame mounted steering box.
Comparing it to a Honda ... well ... kinda goes beyond apples to oranges there really. Rack and pinions are inherently far more stable than any SFA ever will be.
For what it's worth my Trac bar is currently 4.5" shorter than my drag link, used to be an even 9". Bumpsteer is close to what it was feeling like stock. As long as the angles are as close as possible to equal and you pay attention to the arcs of travel ... Bumpsteer will be minimized. Not gone, but within acceptable norms. Plenty of others here rolling on shorter Tracbar than drag links. It becomes part of the compromises after a certain point when you lift a jeep.

 

[Tim_MN]

Just got done doing some measurements. The toe is perfect and the axle is only about 1/2" farther over on the passenger side.

At about 1/2 inch or so is when I would expect some mild bump steer. The obvious easy/cheap solution is to center the axle. If there are indications of wobble, you should diagnose and fix that.

I am not any good at trig, but I have built a few lifted XJ's, and bumpsteer caused by the draglink/trackbar length has never really been an issue.

 

[x-jay vision]

I think you are confusing 2 issues. Wobble is bad. For that I would first check ball joints, then I would look at track bar axle side mount, upper control arm bushings, lower control arm bushings, track bar frame side mount, in that order.

30 degree steering wheel deflection over a bridge abutment doesn't sound that bad to me. You should center your axle though, it's just crazy to be crabbing down the road.

 

[mtbxj87]

I'm around the same lift height. I may be used to how it drives, after 3years. I still have 235's on stock steel wheels, load range c a/t's. I've noticed tire pressure makes a huge difference. I run about 31 psi. Even 35psi felt harsh and seemed to bounce off bumps. Factory recommends 29psi after all.