Rear Track Bar Replacement Opinions

[kalmairn]

Our Jeep has a 2.5" lift using OME springs, Rancho 5000x shocks. We've replaced all the suspension except the rear track bar with Moog (factory equivalent) hardware. The front track bar is Moog, not adjustable.

The bushings in my rear track bar are worn out. They seem to be allowing some additional movement, which can give the Jeep a little "rear steer " feeling. I'm looking at options.

Do I...

1. Replace with OE-style (Moog)?
2. Add a little cost to pick up one of the less expensive adjustable bars to center the axle? (Rough Country, $60 or so more.)
3. Leave the old one and upgrade later?

I'd also consider bushing replacement if I could find bushings and a shop to press them. The hassle of getting the bushings installed and the cost of those bushings, a new bar seems to be the reasonable alternative.

 

[TurboTJ]

Did you install the OME relocation bracket? That should 1) center the axle and 2) minimize bump steer.

 

[TheBoogieman]

Get a Moog rear track bar with a relocation bracket, if you don't have one already.

 

[Jerry Bransford]

Did you install the OME relocation bracket? That should 1) center the axle and 2) minimize bump steer.

Bump steer has nothing to do with the rear axle.

 

[TheBoogieman]

minimize bump steer.

I've never experienced rear bump steer.

 

[TurboTJ]

Bump steer has nothing to do with the rear axle.

Hmmm, well that is news. I assumed that if the track bar is not level at ride height there will be some bump steer. Not so?

 

[Jerry Bransford]

Hmmm, well that is news. I assumed that if the track bar is not level at ride height there will be some bump steer. Not so?

Bump steer is an issue with the front axle's steering geometry. And where the front axle is concerned, you don't want the track bar level, you want it parallel to the drag link. Bump steer is when the steering is forced (bumped) left/right as the front axle moves up/down over bumps/dips on the road. That problem is caused by bad steering geometry... like when the track bar and drag link are not operating in parallel planes.

In the rear, the track bar's angle won't affect or cause bump steer.

 

[TurboTJ]

I guess bump steer was the wrong term to use. But would you agree that the lateral movement of the rear axle in bumps is more pronounced when the track bar is not level?

 

[AjRagno]

Best option with the OME 2.5" springs will be the JKS OGS151 rear track bar. Unless you have a rear CV driveshaft, you will not need the JKS bracket.

I would recommend avoiding use of the OME rear trackbar relocation bracket. It requires an addition 2" bump stop to avoid hitting the tub and there are also reports of it cutting the fuel pump wiring harness.

 

[Tob]

the lateral movement of the rear axle in bumps is more pronounced when the track bar is not level

Correct

 

[kalmairn]

In my case, I'm getting a little "rear steer," not so much "bump steer." It's easiest felt in cornering, particularly slower speeds and sharper turns, particularly if the turn is off-camber. This is why I think it's related to the track bar, it takes something to make the rear end "want" to move around.

@AjRagno - great link. I'd not found the JKS bar for less than $250 - seems most kits include the relocation bracket. That looks like the best answer for my needs - thanks!

 

[WallyWest]

I guess bump steer was the wrong term to use. But would you agree that the lateral movement of the rear axle in bumps is more pronounced when the track bar is not level?

Level? Mine is very much not level, and also has a couple decent bends in it.

 

[Tob]

Level? Mine is very much not level, and also has a couple decent bends in it.

The further away the trackbar's resting position gets from horizontal, the more lateral movement introduced into suspension travel.

 

[JeepingNet]

I'd get the JKS adustable then down the road you can get the CV bracket if you go bigger or belly up.

 

[EzPeezy]

I've had good luck with the rough country rear adjustable track bar.

 

[Goatman]

Is there any actual play in the trackbar bushings? I'd pull the bar and see what kind of shape they are in. Confirm the relocation bracket is installed and that nothing is binding during suspension flex.
Have you checked your rear antisway bar for worn bushings? Some of what you described could be due to that.
Jack up the rear end and check the brakes aren't dragging (emergency brake too if you have rear disks), and there is no play in the axle shaft bearing.
Also try rotating tires front to back. That may help. And if your looseness moves too then you have either a tire or rim issue to look into.

 

[cpwolf]

In my case, I'm getting a little "rear steer," not so much "bump steer." It's easiest felt in cornering, particularly slower speeds and sharper turns, particularly if the turn is off-camber. This is why I think it's related to the track bar, it takes something to make the rear end "want" to move around.

Curious, when doing 35-45 mph can you let off the accelerator and push back on and feel the ass end move around under you?
I had your issue plus that this past spring when I got my TJ back from my son.

Didn’t look loose, but I pulled the Control Arms, way gone! I replaced the CA’s (you could just do bushings) the sway bar bushings and the track bar bushings. All the loose rear end 100% Gone afterwards. Your issues back there sound like worn components, and if one is worn there’s a chance many are worn.

 

[kalmairn]

Is there any actual play in the trackbar bushings? I'd pull the bar and see what kind of shape they are in. Confirm the relocation bracket is installed and that nothing is binding during suspension flex.
Have you checked your rear antisway bar for worn bushings? Some of what you described could be due to that.
Jack up the rear end and check the brakes aren't dragging (emergency brake too if you have rear disks), and there is no play in the axle shaft bearing.
Also try rotating tires front to back. That may help. And if your looseness moves too then you have either a tire or rim issue to look into.

Thank you for the suggestions!

The rear trackbar bushings are visibly cracked. I've not pulled the bar out to check to see if there's a lot of play, but based on the bushings on other hardware (control arms, front trackbar) the rubber will almost certainly be soft.

I didn't install the relocation bracket. I agree there's a chance the axle position / trackbar length is creating some of the issue. I'm not convinced I want the relocation due to potential clearance issues.

I'll check the rear brakes (drums) - that's a great suggestion. I've never had them free when the Jeep was in the air. Since I also see a little pulling, this is a very real possibility.

Curious, when doing 35-45 mph can you let off the accelerator and push back on and feel the ass end move around under you?
I had your issue plus that this past spring when I got my TJ back from my son.

Didn’t look loose, but I pulled the Control Arms, way gone! I replaced the CA’s (you could just do bushings) the sway bar bushings and the track bar bushings. All the loose rear end 100% Gone afterwards. Your issues back there sound like worn components, and if one is worn there’s a chance many are worn.

I'll try that - decelerating from 45mph by engine braking.

I replaced all the rear end suspension in the last couple months - springs, shocks, upper and lower control arms. The only original component left is the trackbar, which I know has worn bushings.

 

[cpwolf]

I'll try that - decelerating from 45mph by engine braking.

I replaced all the rear end suspension in the last couple months - springs, shocks, upper and lower control arms. The only original component left is the trackbar, which I know has worn bushings.

I meant more press on and off the accelerator, my rear end would have a loose "twist" feel like it was moving under my seat, side to side with the torque. All my suspension bushings were toast.

If yours were toast, then I would agree time to finish the job, track bar bushings and sway bar as well, you didn't mention changing those or maybe I missed it. I'd get all that tight. Just having offset axle by 1/2" or so because of the lift pulling it without an adjustable track bar, I haven't seen cause what you're saying or read that on here either.

Those bushings need to be replaced as you stated, so I wouldn't go down any other routes until that was buttoned up. No need to go "fixing" things that don't need fixing in my opinion.