front geometry

[omega_rugal]

does the XJ/MJ front geometry change when you turn the steering wheel? i lately noticed that when i turn the wheel all the way the front leans to that side, is this normal o something is wrong?

[eaglescout526]

I say if it seems funky to you, I would check for some play in the steering components like the track bar.

[derf]

The steering knuckles turn on an angle so it does look "a little weird" the first time you pay attention.  And the inverted Y link will change a little from lock to lock.  These are normal behaviors for stock steering components.

 

But if it's acting really weird and moving around a ton, you may have worn out steering components that need to be replaced.

[omega_rugal]

something is wrong, again, the dreaded death wobble is back... it went away when i tightened the steering box but now it feels loose again, i don't know if i should tight it, i´m afraid that i´m only masking the real cause

[Eagle]

1 hour ago, omega_rugal said:

something is wrong, again, the dreaded death wobble is back... it went away when i tightened the steering box but now it feels loose again, i don't know if i should tight it, i´m afraid that i´m only masking the real cause

 

An automotive wheel/tire is a gyroscope. Its natural tendency is to rotate true to its axis. If it wobbles, that means the wheel/tire is not balanced. Irrespective of loose track bars, loose tie rod ends, or anything else that may contribute to the severity -- none of those factors can cause death wobble. If anything, a properly balanced tire will cancel out any tendency to wobble, due to the gyroscope effect.

 

The track bar on my original '88 Cherokee went bad late in the autumn one year, and I didn't get to replace it before the snow flew. I drove it to work every day for the entire winter, with about a quarter turn of free play at the steering wheel, before the snow melted and it warmed up enough for me to replace the track bar. There was never a hint of death wobble.

 

Have your tires balanced.

[Minuit]

If your front tires are out of balance laterally (also known as "dynamic imbalance", also known as "side-to-side shakiness"), that can be the root cause of death wobble. That was it in my '89. Replacing suspension parts made it better, but it never addressed the root cause. As a side note - 99% of MJs are probably driving around on worn steering dampers. Replace it, but replace it after the death wobble is solved.

 

I got full-on death wobble on the way to the tire shop hitting an expansion joint at 40 mph. Since having "new" tires put on, I've been intentionally driving right into every bump I can trying to make it happen. Hasn't done it a single time.

 

Side note - the only time I've experienced anything close to death wobble in my '91, it was from the right front wheel being held on by three broken studs and two very loose lugnuts. I'm a believer now - in cases of death wobble, look to the tires and wheels first.

[derf]

1 hour ago, Eagle said:

 

An automotive wheel/tire is a gyroscope. Its natural tendency is to rotate true to its axis. If it wobbles, that means the wheel/tire is not balanced. Irrespective of loose track bars, loose tie rod ends, or anything else that may contribute to the severity -- none of those factors can cause death wobble. If anything, a properly balanced tire will cancel out any tendency to wobble, due to the gyroscope effect.

 

The track bar on my original '88 Cherokee went bad late in the autumn one year, and I didn't get to replace it before the snow flew. I drove it to work every day for the entire winter, with about a quarter turn of free play at the steering wheel, before the snow melted and it warmed up enough for me to replace the track bar. There was never a hint of death wobble.

 

Have your tires balanced.

A friend of mine recently encountered death wobble.  The upper track bar bolt came loose and she had a ton of play.  Tightened it back up and her death wobble went away completely.  The tires were balanced fine.  The rest of the suspension was fine.  The ball joints aren't new but they aren't worn out.  We would have replaced them except for the fact that the DSPO (Dip "Stick" Previous Owner) welded them in... /facepalm.

 

I've experienced death wobble twice myself and had two different solutions required, replacing various worn suspension and/or steering components.

 

What I've learned over the years is that there are many causes and manifestations of death wobble.   The entire steering and suspension system is just that.  A whole system.  Anything that allows a feedback loop will lead to death wobble in one way or another.  It can appear as a side to side shimmy.  It can also show up as a bouncing up and down rhythm where the axle "flexes" back and forth.  I got to watch a buddy in my rear view mirror as his death wobble kicked in.  The whole front axle was bouncing as if on a pivot.  As one side came up, the other side tire hit the ground and bounced, causing it to come up and the other side coming down and hitting.  Back and forth, back and forth.  It was pretty impressive.

 

Bottom line is that if you have death wobble, you need to check everything.  Ball joints, control arm bushings, tie rod and drag link ends, track bar bushings, swaybar links, tire balance.  Check all of it.  If anything is worn or out of spec, fix it.  Then when you fixed your death wobble, you can pay attention to the steering stabilizer.

[omega_rugal]

the death wobble happens at 45 mph or more and when hitting large bumps, or several small bumps in succesion, i lifted the front axle this afternoon and everything looks solid except when i push the wheel hard i notice that the steering box rocks a little, not the pitman arm, the entire box, i´ll do more tests tomorrow, until i find the culprit, back to 3rd gear only ...

[Eagle]

I don't remember -- does your MJ have a lift? What's your caster angle? Reduced caster contributes to death wobble.

 

[omega_rugal]

no lift, the suspension is all stock, too stock if you ask me, need to change those bushings ASAP, caster is a little off because my MJ was in a crash, the front is slighty bent to the passenger side...

[omega_rugal]

i found one culprit, the track bar bolt was a little loose, tighted it, the steering feels firm, the steering box moves a little but only if i really push on the steering wheel, i don´t know if that can be fixed or if if caused the death wobble, i also retightened the steering box a bit, i have already tightened like a full turn, does that mean my SB is toast?

[eaglescout526]

6 minutes ago, omega_rugal said:

does that mean my SB is toast?

Probably. I did the same thing when I was installing AC as you can’t access that nut with the 2.5L radiator in the way. I had my dad wiggle the wheel back and forth to take out slop but slop never came out. 

[AZJeff]

22 minutes ago, omega_rugal said:

i found one culprit, the track bar bolt was a little loose, tighted it, the steering feels firm, the steering box moves a little but only if i really push on the steering wheel, i don´t know if that can be fixed or if if caused the death wobble, i also retightened the steering box a bit, i have already tightened like a full turn, does that mean my SB is toast?

You say you "tightened the steering box a full turn".    Does that mean you turned the pitman shaft screw on the top of the box a FULL TURN?   That's WAY more than what would be expected for "tightening up" a slightly loose box.   A quarter turn is more expected.

 

If you turned it that much, there is a good chance you have created binding in the box, but that can only be detected by having the front end unloaded (no weight on wheels), and even then, it's hard to determine unless the pitman arm is disconnected from the drag link.

 

If your box has 150K miles or more a new (reman) box would be a wise move, assuming you have more than normal play in the box proper.   Notice I say "the box proper", because lots of guys try to address steering linkage looseness issues by cranking on the pitman shaft thrust screw, and all that does is trash the steering box.

[omega_rugal]

4 minutes ago, AZJeff said:

Does that mean you turned the pitman shaft screw on the top of the box a FULL TURN?

 

nope, a few dregrees each time, i calculate that IN TOTAL i have turned it like 300 degrees...

[Eagle]

29 minutes ago, omega_rugal said:

 

nope, a few dregrees each time, i calculate that IN TOTAL i have turned it like 300 degrees...

 

IMHO that means your steering box is toast. It shouldn't take more than an eighth or a quarter turn to bring a steering box back to better-than-new adjustment.

 

AZJeff is entirely correct -- many steering boxes have been ruined by adjusting improperly or too much. The shop at my dealership refuses to even touch that adjustment, because they're afraid they'll do more harm than good. Once it has been over-tightened, the box wears rapidly, and after that adjustment is just like a dog chasing its tail. You'll never win.

 

[omega_rugal]

the one from a  durango it´s a good upgrade right? those show up in junkyards often...