I have bump steer. It's pretty bad, and makes driving at speed pretty sketchy. I recently installed a Teraflex 4" L.A. kit, bump steer started after the installation.
I think I could probably solve this a few different ways, but looking on advice on the best way to do it. As always, money is a factor, a cost effective solution that solves the problem is preferred.
My current setup:
Teraflex 4" L.A. Kit
Teraflex front adjustable track bar, attached to the stock frame, and axle pivots.
Rusty's heavy duty tie-rod and drag link.
Drop pitman arm (which came with the Tera lift)
According to my best measurements, the track bar and drag link are not parallel by 6°.
1) Remove pitman arm drop, and replace with standard pitman arm. (not sure if this will provide enough correction)
2) Install a track bar relocator bracket on the frame mount of the axle.
3) Install and track bar relocator bracket on the axle end of the track bar. (Does this even exist?)
4) Change the Rusty's Heavy duty Tie rod and Drag link to something different. (I've read the Rusty's system produces a dead zone in the steering wheel, and wouldn't mind addressing that issue as well with a new system)
Easy peasy, get rid of the DPA (no drop track bar bracket = no dpa). Surprised when you searched the forum for bumpsteer (you DID search before posting right?), that would be the predominant commonality in all bumpsteer threads.
Kudos on providing the picture though.
Remove the DPA, then the driver side of the drag lank will be higher, which will make it more parallel to the track bar.
I think putting the standard pitman arm back in will help for sure, but not even come close to providing enough of a change to make things acceptable for driving.
It looks like the pitman arm pivot needs to be brough up by about 4" to fix it, whereas a standard pitman arm will do about 1.5-2"??
I'm leaning towards getting a bracket, and installing a standard pitman arm just to fine tune the system if required.
I could also rotate the tie rod, so that the ball joint connecting the drag link to the tie rod is IN FRONT of the tie rod, instead of on top. This will correct the angle a bit, but also make the tie rod rotate up and down while steering, contributing to the dead zone I currently have a problem with. I actually used to run the tie-rod this way before the lift.
As rikkards said, it's been well documented that the DPA contributes towards bumpsteer.
A bracket will help, but they add a lot of clearance issues (see the huge thread about trackbars).
For the steering dead spot, just replace your steering linkage with the Currie set-up or the ZJ tie rod.
I have heard good things about the currie system, and I'll look into that.
Lately I've been getting increasingly fed up with just throwing money at the Jeep and hoping problems go away. If for example the steering slop is caused by a loose steering gear, the Currie/ZJ setups will have been a bit of a waste of money. I'd rather spend more time isolating the problem before pulling the trigger on parts.
I agree the Currie system may be a very effective solution, but if I can have the same effectiveness from a track bar relocator bracket, for significantly less $$, I'd rather go that route. Anyone have experience with those? Is an axle relocator bracket better than a frame bracket? I've seen a frame tear out at the frame bracket.... Hence why I'm leaning towards the axle bracket.
I guess I should reset my steering gear backlash, and evaluate if the slop is removed. If not, the Currie system becomes the next step, and may solve the bump steer thing too.
Lately I've been getting increasingly fed up with just throwing money at the Jeep and hoping problems go away. If for example the steering slop is caused by a loose steering gear, the Currie/ZJ setups will have been a bit of a waste of money. I'd rather spend more time isolating the problem before pulling the trigger on parts
it is aggravating, and its why its better to read first. i doubt you will find many quality reviews on a rusty product for a TJ or the Inverted T steering design.
go back to the inverted Y and you will be a happy man. the ZJ setup can be had for under $200 if you need the drag link as well
Yeah ZJ tie rod is appealing too. I would need a new drag link, which is the reason the Rusty's kit is in there in the first place. I don't really want to put a stock drag link back in there, I don't like how the entire drag link needs to be replaced when the tie rod end wears out, or the boot cracks. I might just go that route anyways though. Other options really are expensive, and may not be worth it.
Lose the DPA. Sell the T.
2" of lift is a great candidate for ZJ steering, and well within the working limits of the inverted Y.
Don't buy the Currie kit yet, you can bend a half dozen ZJ rods for the price of the Currie.
Any major deviation from stock geometry in my opinion is ill advised (says a guy with full crossover).
Using the picture I took this morning, and some CAD software, I can draw approximate locations of different steering setups, and measure the resulting angle between the track bar and drag link. See below for the pic.
Looks like the closest to parallel I can get will be with a track bar relocator bracket. I only mocked up a bracket on the axle end, but I think a bracket on the Frame end would achieve the same thing.
What is a bit startling, is that the Currie system (which is same a stock geometry) with stock pitman arm is almost as bad as my current setup. If people are giving good reviews on the currie, the values I'm getting from the picture might not be accurate. I may have to get some string out, and do some real measurements on the TJ.
Fortunately, the Rusty steering system is almost dead-in line with the stock pitman arm. Which is probably by design. This means that if I do put a bracket in there to solve my current bump steer, I could upgrade to the Currie system, or the ZJ tie rod at a later date and not mess anything up.
Edit: Just saw an error with the second photo, should read "stock drag link with dropped pitman arm".
After quickly mocking up stock drag link with stock pitman arm, misalignment is closer to 2°. I could probably get away with putting a standard pitman arm in there, and I may or may not need to rotate the tie rod so the drag link connects to the tie rod in the front, instead of the top. This may get the track bar and drag link nearly perfect. Currently sourcing a stock pitman arm...
Last edited by mike m2; 06-25-2014 at 06:52 AM..
Reason: Noticed an error with a photo...
I got out into the garage with a digital level and some string to measure the misalignment between track bar and drag link. Then removed the drop pitman arm and installed a new stock pitman arm.
Before (drop pitman arm w/ Rusty's drag link): 5.5° of misalignment between track bar and drag link.
After (stock pitman arm w/ Rusty's drag link): 0.6° of misalignment between track bar and drag link.
Went for a rip, and took some speed bumps at various speeds, and bump steer is completely gone. Jeep feel significantly more stable on the highway, and on bumpy roads.
Interestingly, measuring misalignment with a digital level and some string, and measuring it with a carefully taken photo had very similar results. (5.5° vs. 6.3°, only 13% error with the photograph).
With this problem, some patience and measuring meant that the problem was fixed for about $20 in parts. Had I decided to just throw money at this, It would have been around $300 (for a new ZJ setup).