Instability over 40
 

:dunno:Hey all, so here's the problem:
My jeep is very unstable, as in it likes to go left or right, especially on braking over 40mph.

Some background:
99 jeep xj
4.0
All new brakes
No detectable loose parts in suspension or steering.
Rough country 2 year old Shocks are pretty soft
31" tires (lifted 3" with new springs ((2 years old))
Bushings around the sway bar are getting warn.


What are some causes of the diving left/right on braking over ~40mph. It has gotten to a point where I don't like driving it on the freeway.

Thanks!

Can you be more specific? Does it wander while cruising or when braking only? What do you mean new brakes? New rotors, calipers, pads, hoses, lines?

The wandering could be as easy as alignment. Start doing all the checks. Bushings on all steering components, ball joints...shocks wouldn't do anything to your steering; hard or soft.

Folks on here have replaced calipers before and gotten the wrong size caliper. Look into that as well. Those folks were talking about brake steer as well.

Sounds like the steering box. Do you have to over compensate with the steering wheel to control the vehicle?

New calipers rotors and pads done by the dealer, so that's not the issue. I even had them re-check.

The steering is loose just driving on the freeway but around town you really notice the amount of muscle you put into steering, like power steering may be going out.

And yes, I have to compensate when braking as its trying to dive, its just minor wheel adjustment required to keep control, with that said... Holding the wheel completely solid and still it will still drift side to side when braking.

Done this since the lift was installed? How's the steering stabilizer?

No, I'm 2 years on the lift, a couple months on the problem.

I'm not sure how the steering stabilizer is, I mean iit looks Okay... How would I check

Something has to be.

That may be so, steering components are my least knowledge area, I have been under the jeep and have pulled on all bars and parts and I can't find anything not solid.

Can someone suggest a list of parts to check, how to check them, and how to tell if they are good or bad.

Thanks for helping guys

Instability over 40
 

If your unsure about steering I would have an alignment done at a reputable shop. They will check for loose components. Let them know what your experiencing and they can almost always find the issue. Still verify their findings but a good shop should never reccomend more than is necessary. The steering stabilizer is just a bandaid to any problems. Don't replace it until you have fixed the actual problem. You should be able to drive entirely without it and never notice a difference of everything is right in the front end.

The dealer didn't come up with anything when they drove it except for.... It isn't the brakes...

And my tire wear is equal, wouldn't that rule out an alignment problem

Have someone inside the vehicle
1. Shaking the steering wheel side to side,
2. Turning the wheel L-R full lock,
while you are underneath watching the steering components. I'll bet the issue will be obvious.

Excellent, I'll do that tomorrow, in the meantime any ideas what part it could be other than allignment?

Sometimes you need to have the tires off the ground to see the problem. The weight of the vehicle on the tires makes things seem solid that really aren't.

Worth a try.

Control arm bushings that are split can cause this behavior when braking and can cause strange wandering issues when driving.
When brake is applied the axle wants to rotate, a split bushing will allow movement/rotation of axle, changing the steering dynamics.
Uneven braking with new brakes can also be caused by grooves worn into the slides that pads rest on. The groove prevents pads from closing and can cause uneven braking. Can also cause sticking brakes.

I have discovered bad bushings the following way, hang head out window to watch wheel center, place jeep in D and roll forward a few feet then press brake, watch for wheel center to shift. Do the same in Reverse.
When I had bad upper bushings, axle would shift when jeep was rolled in reverse and brake applied.
Also visually inspect, control arm bolts should be centered in bushing. A split bushing will allow the bolt and sleeve to be way off-center.

Instability over 40
 

The dealer doesn't know **** about the front end. At least around me. I would still get it checked. Worst case scenario it isn't off and you don't get charged. Best case they find the loose part or your alignment was knocked way off. Tire wear takes time to show up and sometimes never does if its just the toe that is off.