sik_xj

Oh but it is.

I feel like a dick for posting yet another one but I have yet to find a solution after hours of researching.
So I have a 99 Cherokee that has been lifted for about a year now with a 4.5 inch lift and long arms. I had a single sheet track bar with the stock bracket that did me well but I wanted to upgrade to a double sheer.
So I replaced the track bar, and drove it around the block a few times with no issues got it up to about 45 on smooth pavement and no issues.
So I take the Jeep out the next day on the highway and I hit a bump and got the worst death wobble I have every felt. I pulled over and it stopped and then I continued driving and thought it was a fluke. Well it happened again at slower speeds..about 30-35 mph.
I took it home, jacked it up went over every front end component I could test. Upper control arm bushings on the axle side were good with minimal play, upper and lower ball joints seemed good.
The steering had next to no play in it. The track bar is brand new and rock solid, the steering box is pretty solid as well with no play.
I don't have horrendous angles with my drag link and track bar..the tires are pretty much new and have been balanced with no issue for about a year.
The jeep has not been wheeled and is usually parked at home every day with maybe 10 miles a week put on it.

So my question is why the horrible wobble after the new track bar?
I read that alignment can cause this..but other than the axle being shifted maybe an inch over the toe should still be in spec, no?
Why would alignment cause the wobble?

Any help would be appreciated, and fast because I am due to leave on a road trip in about 3 hours.

Thank!

sik_xj

My phone corrected wobble with wonble for whatever reason in the title..that was actually kind of funny.


I saw it today...and had to fix it..LOL...willys55

sik_xj

anyone have anything?

evan00xj

I must have answered at least 5 people on here about death wobble / steering issues in the past month....for the um teenth time:
Have you had the vehicle professionally aligned?
Ball joints
Wheel bearings
Tie rod
Drag link
TRE at pitman arm
Track bar and bolts / heim make sure the track bar mount isn't wallowed out
Check axle side
Control arm bushings
Steering box, steering box bolts, is the frame cracked?
Is your sway bar connected?
Whats the condition of your tires and wheels?
Have they been properly balanced?
Have you looked under there while a friend is turning the wheel back and forth?
IMHO the factory y setup is a joke once your over 3" lift. (Buts Thats just me)

sik_xj

Yes, thats why I said I feel like a dick for posting again because I know most of those causes. I checked everything above and visually and from what I can test they all tested good.
My question that I searched for and couldn't find is how/why can a vehicle getting a brand new track bar, bracket, and moving the axle <1 inch cause death wobble. The only thing I can think of is alignment, but how would that little change throw that much off.
I have been running this setup for about a year with no issues. I wanted to upgrade my bds bar a bit for a double sheer, that is the only thing that has been changed.

spaz_22

what brand is your new track bar? did you make sure it wasnt a drop bracket that requires a drop pitman arm? if your drag link and track bar are not parallel this will cause death wobble

sik_xj

I thought that it would only cause bump steer.
The track bar I had before and the drag link weren't perfectly parallel and I didn't have any issues. Now it is a little further off from being parallel but like I said before its not horrendous.
I don't see how that alone would cause such an issue now.
It is not speed dependent..only if I hit a bump just right.

ohio95xj

After that last sentence, my money is on the drag link-track bar angles being off

SteveMongr

The track-bar / drag-link relation can and will cause bump steer and the Wobble. Must be parallel from joint to joint.
Measure and compare the track-bar Bracket and your stock bracket. The hole for the bar should be the same length off the 'frame' rail for both. If not than you need a different bracket that matches stock.
Using a drop pitman arm is not the best way to match them up. And is not necessary at 4.5".
Check the heim joint on that double shear.
I use a RockKrawler double shear and the heavy duty bracket is the same size,placement as stock. 4.5" lift and drop brackets. No bump steer or wobble.

freegdr

Axle being recentered with new track bar could of released some tension from pulling axle off to one side. . Did new bolts fit snug when going thru mounting brackets .Whats caster set at ?http://go.jeep-xj.info/HowtoAlignment.htm

sik_xj

Thanks for the link.
I am going to have it professionally aligned this weekend.
The bolts are all very snug in the holes.
As for the caster it was set at spec whenever it was aligned last but since then the new track bar has been put on and that's when problems arose.

sik_xj

I believe that the cracked I have drops the track bar just a tad from the stock location.
The angles being off just a matter of <10 degrees will cause this severe of a problem?
I guess I can't wrap my head around why it would cause such a severe problem when hitting a bump. If the axle is held stationary via the track bar and the axle is held from moving towards the back and front by the long arms then it has to be steering related, right?

evan00xj

What long arm setup are you running?

SteveMongr

Yes, it is steering related, but not the cause.
If the relation between the trac-bar/drag-link is off parallel by 10degrees than the steering moves when the suspension moves.
So, you hit a bump and cycle the suspension, the axle goes up which causes the wheels to turn right. The axle returns and the wheels turn left. This quickly sets up an oscillation because the suspension continues to move a bit. This is the 'wobble'.
Once this oscillation is initiated it feeds off its own energy and gets worse until you slow down to settle it.
I do not think an alighnment shop will help. But when it comes to doing the XJ you can dial that in yourself very close, then ask the shop for a 'printout' of your alighnment and adjust yourself back at home. Printouts are usually free.
Good Luck. I believe it is that 10 degree diff. If it changed position with that bracket than that is the culprit.

sik_xj

Okay awesome information.
That makes sense now I guess I didn't really think of it that way.
I think the alignment changed a bit with the installation of a new track bar.
I think that I will focus on getting the drag link close to parallel with the track bar.