Bad wobble between 45-55 mph.. Need help!! (long)

[Talyn]

I have been fighting a wobble between 45-55 mph (and comes back aroun 75 mph a bit) for the past 3 months. It gets worse over bumps, but at about 60mph is it perfect. It isn't death wobble though, but it is a heavy wobble (like pre-death wobble). It will wobble on a perfectly flat surface with no bumps.

My specs:
2000 XJ
3.25" front (spacers + ZJ V8 springs)
3.5" rear (RE AAL)
DT3000 shocks
JKS BPEs
JKS QDIIs
JKS Track bar
Yokohama Geolander II + 255/70-16 tires
OME HD SS
Stock CAs
I think that is it.

What I have done so far:
New left side ball joints
New u-joints in axle
New TRE at pitman arm
Removed front drive shaft
Had the alignment checked 3 times (will gives specs later)
Tires have been balanced several times by different shops.
I have swapped the front tires with another XJ with stock size tires.. wobble was better but was still there. He also detected no wobble running my tires on his XJ (would pint to my suspension).
I also swapped tires with PA Highlander and he also found nothing unusual with my tires on his XJ.. but I couldn't fit his on mine.
Also, swapped tires off a brand new Liberty and the wobble went away (would point me to the tires)
4 separate shops have found nothing wrong with my front suspension.. nothing lose at all.
The dealer put the XJ on jack stands under the axles and ran it into the wobble range, but found no wobbling.

Alignment specs:
Front:
Camber: L -0.5; R -0.4
Caster: L 7.2; R 6.9
Toe: L 0.02; R 0.01; Total: 0.03
Steer Ahead: 0.00

Rear:
Camber: L -0.3; R-0.1
Toe: L -0.21; R 0.19; Total: -0.03
Thrust angle: -0.20

All the specs ate good aside from the thrust angle... that is out .05* from spec of -.15 to .15. I will be rectifying that though, but would that cause a wobble?

I think I have listed every pertaining detail.

Any suggestions?

Thanx,
Chris

[RCP Phx]

When it comes to "wobble",everything must be checked thoroughly! The rubber compound in the new XJ's ca's is extremely soft!

[Talyn]

I was thinking that as well... they seem a bit easy to move by hand (but teh bushings are good).. I only know of one other person that is having the same exact problem as I am. Anyone think it could be teh CA bushings?

[TOZOVR]

What do your tires look like? Are they worn down?

[Talyn]

They have about 9000 miles on them, mounted them in November of 2002 and have a little less that 1/3 of wear.

-Chris

[rockwerks]

It has to be wheel balance...if teh problem recurrs @ set speed the wheel tire combo is out of balance...make sure your shop is blanceing to 75 mph...most only balance to around 45

[Talyn]

Originally posted by xjnation
It has to be wheel balance...if teh problem recurrs @ set speed the wheel tire combo is out of balance...make sure your shop is blanceing to 75 mph...most only balance to around 45

It isn't... for several reasons.
1) A unbalanced tire (slightly unbalanced) would cause more like a vibe.. this is a true wobble.
2) I have had umm... 4 shops balance them... no difference
3) from initial post:
"I have swapped the front tires with another XJ with stock size tires.. wobble was better but was still there. He also detected no wobble running my tires on his XJ (would pint to my suspension).
I also swapped tires with PA Highlander and he also found nothing unusual with my tires on his XJ.. but I couldn't fit his on mine.
Also, swapped tires off a brand new Liberty and the wobble went away (would point me to the tires)
4 separate shops have found nothing wrong with my front suspension.. nothing lose at all.
The dealer put the XJ on jack stands under the axles and ran it into the wobble range, but found no wobbling."

-Chris

[Tom R.]

Steel or alloy rims? If steel, look at the possibility of having a bent rim.....or more than one bent rim. Second, check the shocks for play where they mount and for overall shock serviceability.

Tom

[MaXJohnson]

Have you checked for brake rotor warpage? Bent wheel? Try playing with air pressure, both up and down. What pressure are you running now? You're bound to find something loose in the front end that is allowing the wobble. As RCP Phx mentioned, control arm bushings could be suspect. Does the JKS track bar run rubber at both ends?

The dealers test, using jack stands isn't valid. The effective spring rate provided by tire sidewalls and tread squirm are eliminated with the axle rigidly mounted on the jack stands. This drastically changes the natural frequency of the axle/tire assembly which is a factor in the wobble. Swapping to different size tires has a related effect and should result in a change in the speed at which the wobble occurs.

[Talyn]

Originally posted by MaXJohnson
Have you checked for brake rotor warpage? Bent wheel? Try playing with air pressure, both up and down. What pressure are you running now? You're bound to find something loose in the front end that is allowing the wobble. As RCP Phx mentioned, control arm bushings could be suspect. Does the JKS track bar run rubber at both ends?

The dealers test, using jack stands isn't valid. The effective spring rate provided by tire sidewalls and tread squirm are eliminated with the axle rigidly mounted on the jack stands. This drastically changes the natural frequency of the axle/tire assembly which is a factor in the wobble. Swapping to different size tires has a related effect and should result in a change in the speed at which the wobble occurs.

Well, if it was a bent wheel it would have shown up on the other XJs they were on. I iwll try the air pressure.. it is currently at 30psi front, 29 rear. Te JKS has rubber at one end but i don't know what exactly to call the large ball type bushing at the frame side.

I took into account the speed change in the smaller tires. Tested it under and ove rthe speed range it happens.. all the way up to 85 mph and it was fine.

As for teh brakes... it doesn't really act like brake rotors... it is there regardless of wether the brakes are applied or not, It goes away after a certain speed, but if the speed is dropped (coasting) the wobble will return even without braking, and I can hit the brakes out of the 45-55 mph range and there is no wobble. I will, however, put some stock rotors on tomorrow just to verify.

-Chris

[Eagle]

Originally posted by Talyn
1) A unbalanced tire (slightly unbalanced) would cause more like a vibe.. this is a true wobble.

I disagree. "Vibes" are vibrations -- they are fairly high frequency, small amplitude oscillations. There is simply no way that an out-of-balance tire and/or a bent wheel rim can cause anything remotely similar to a vibration.

MaXJohnson has a good suggestion in looking at rotors and bearings. The only time I experienced true death wobble was in a totally stock 1999 WJ (Grand Cherokee) with about 10,000 miles on the odometer at the time. What set off the episode of DW was a warped front rotor.

[Tom R.]

Oh yeah, I forgot to mention the rotors. I just went through this with rotors that were bad from the get-go.

Tom

[Talyn]

Brakes are good.. put some new rotors in and the wobble is still there. Bearings are good as well. Replaced the control arms bushings with some ones I had laying around (from a previous XJ that I never got aroudn to install them on). Wobble a bit better, but still there.

-Chris

[ChuckD]

Are you the original owner of the XJ, just asking if it may have had any damage repaired from a wreck.

You mention wobble, where on the scale is it. 1-10, 1 being bad road, to 10 being I'm going to die. Has anyone else test driven your XJ?

The only advise would be to look into some LCA's, your specs look good as far as caster, but maybe your tires are not centered propperly. Also using the ZJ springs and spacers with the OEM LCA's maybe keeping the suspension from moving through the proper geometry.

[Talyn]

Originally posted by XJCHUCK72
Are you the original owner of the XJ, just asking if it may have had any damage repaired from a wreck.

You mention wobble, where on the scale is it. 1-10, 1 being bad road, to 10 being I'm going to die. Has anyone else test driven your XJ?

The only advise would be to look into some LCA's, your specs look good as far as caster, but maybe your tires are not centered propperly. Also using the ZJ springs and spacers with the OEM LCA's maybe keeping the suspension from moving through the proper geometry.

I am not the orginal owner, but bought it at about 28,000 miles.. no signs of any accidents.

The wobble is about 6. A few people have test driven it and found it abnormal. It also can happen on a level road with no bumps.

If the wheels aren't centered ( I am assuming you mean length wise) I would also need UCAs as well. Right? I am not seeing how LCAs would help here since the bushings in my stock LCAs have just been replaced.

-Chris

[Flowers]

[QUOTE]Originally posted by Talyn
[What I have done so far:
Also, swapped tires off a brand new Liberty and the wobble went away (would point me to the tires)

Chris,

I applaud you on your thorough investigation!!!!!!!!

I would have said tire balance, until I read your original post. Then I thought wheel balance, until I read your post again. The Liberty wheels and tires, and the fact that you have swapped rims and tires with other Jeeps is what's throwing me off. I wish I could help.

What rims are you running anyway?

Flowers

[Talyn]

Originally posted by Flowers
[QUOTE]Originally posted by Talyn
[What I have done so far:
Also, swapped tires off a brand new Liberty and the wobble went away (would point me to the tires)

Chris,

I applaud you on your thorough investigation!!!!!!!!

I would have said tire balance, until I read your original post. Then I thought wheel balance, until I read your post again. The Liberty wheels and tires, and the fact that you have swapped rims and tires with other Jeeps is what's throwing me off. I wish I could help.

What rims are you running anyway?

Flowers

Ummm.. don't know the name of them. They are the 16" rims that came on the Limited and Classic models. Pics on my website in sig.

Yes, swapping the tires is very confusing. My tires behave fine on 2 XJs, while one pair of front tires still has the wobble, but all 4 from the Liberty have not wobble.

Someone mentioned that a DPA maybe needed.. but this happend on a nice level road with no bumps as well.. so not a lot of steering changes. The JKS track bar does drom the stock piviot point by about an inch, but both the draglink and track bar appear to be parallel. Maybe I should try a ZJ pitman arm? It shouldn't be too much$$.

Ugh.. I must be missing something.

-Chris

[Kudzu]

I can proboly slove your problem i had the same problem on my 01 tried evrything new DS new wheels adn tires whole sooting mathc and the only thing that sloved it was when I put Rusty's LCA from my old 4.5" lift that have the poly bushing. It drives better than it did when i got it new...

[BrokenXJ]

This is something to check, I don't know how old your XJ is, but I had a similar problem of pre death-wobble.

It turns out, all of my grade 8 factory control arm bolts, were seriously worn out. They were actually necked down from thier original size. Also check your steering stabilizer bolt.

[ChuckD]

Originally posted by Talyn
I am not the orginal owner, but bought it at about 28,000 miles.. no signs of any accidents.

The wobble is about 6. A few people have test driven it and found it abnormal. It also can happen on a level road with no bumps.

If the wheels aren't centered ( I am assuming you mean length wise) I would also need UCAs as well. Right? I am not seeing how LCAs would help here since the bushings in my stock LCAs have just been replaced.

-Chris

The length is exactly what I'm talking about. At that hieght just over 3", also you have the spacers, I'm not saying they are bad, but when your axle isn't centered over the spring mounts may be causing your wooble. I know when I was at 3" adding longer LCA's made my XJ more stable. You have done a really good analysis, I'm thinking either there was an accident or your at the point for LCA's. Your caster will change, if your worried get UCA's to boot. Go to the classifieds for cheap used stuff.

[Talyn]

Originally posted by XJCHUCK72
The length is exactly what I'm talking about. At that hieght just over 3", also you have the spacers, I'm not saying they are bad, but when your axle isn't centered over the spring mounts may be causing your wooble. I know when I was at 3" adding longer LCA's made my XJ more stable. You have done a really good analysis, I'm thinking either there was an accident or your at the point for LCA's. Your caster will change, if your worried get UCA's to boot. Go to the classifieds for cheap used stuff.

So you are saying that the extra 1/4" of an inch (by removing spacers from behind the LCAs) or so the aftermarket LCAs will give may help? I have the caster turned up by adding spacers behind the LCA brackets. If I put in aftermarket LCAs I will be keeping the caster the same because if I put my caster any higher my pinion will have issues with the angle on the drive shaft. The only way I would be to push the axle forward anymore would be to get aftermarket UCAs... but all the tables I have seen regarding UCA length at a certain lift height have shown it to be very small over stock measurement.. like 1/8" small.


If I had just paid to get my '91 XJ fixed from the accident.. ugh

-Chris

[ChuckD]

I know, but your not left with much else. I agree, you have the LP D30. You'll need the Aftermarket UCA's to balance out caster and DS angle. Can you take pictures of your springs with your tires off. Maybe we can help you out there.

[RCP Phx]

I have very seldom have found DW or hints of it to be just 1 item.Your switching tires/vehicles really shows this.It is a combination of things allowing movements that I attribute wobbles of any kind to.For me it has usually been trackbar/control arm issues(Ive had it on all four of mine).I highly recommend the RE Extreme Duty trackbar/bracket as something to think about(I got the wobbles on mine at 3000miles@3"+ and a Rusty's trackbar)!Not after that nor since have I even had a hint of wobbles. Now with my long arms I am still running less than 3* of castor with no problem!

[MudDawg]

Have you had your tires checked for true????

Recently I had an alignment and tire rotation done...that caused a minor wobble or "shimmy" at the same speeds...45 to 55 mph..the balance was checked and the tires individually spun up to 80 mph...no sign of vibration...the balance was fine...BUT when they were checked for true or roundness...one was out of round...trued both tires and rebalanced...drives like new now...

[Hawaiian Style]

I have exactly the same problem but mine seems to act up only at 50-55 MPH with the worst of it a 55. I've swapped my AT's and MT's with no real change. Wobble gets agrivated after hitting a bump. The really strange thing is that it happens most of the time, but not all of the time. Been the same way for the 3 years I've owned my XJ both pre and post lift. I can see the front driver's side tire moving when it gets bad... not good, in fact pretty scarey. 3 shops have been unable to find any problem with it. :(

[Rudy]

As dumb as this sounds, when I finally replaced my worn out and over stretched Pro-comp shocks with new Skyjacker shocks with urethane bushings, my wierd 45 to 55 mph wobble went away. I swear thats all I replaced. Good Luck.

[Talyn]

Originally posted by Rudy
As dumb as this sounds, when I finally replaced my worn out and over stretched Pro-comp shocks with new Skyjacker shocks with urethane bushings, my wierd 45 to 55 mph wobble went away. I swear thats all I replaced. Good Luck.

What was your wobble like? Wa sit there even over smooth pavement with out bumps?

-Chris

[Rudy]

Just going down the road, like clockwork at 45mph till about 55mph on smooth pavemant. You could watch the steering wheel start to move back and forth. Nothing violent just a steady wobble and then after 55mph it would go away. I could go 80 without a problem. I replaced tre's, got an R.E. heavy duty track bar and new lower control arm bushings (Rustys), rebalanced the tires to no avail. Thats not to say it's what your problem is , but it worked for me. I just replaced the shocks cause I needed to and that turned out to be the problem, I guess. Good luck and God bless.

[Talyn]

Originally posted by Rudy
Just going down the road, like clockwork at 45mph till about 55mph on smooth pavemant. You could watch the steering wheel start to move back and forth. Nothing violent just a steady wobble and then after 55mph it would go away. I could go 80 without a problem. I replaced tre's, got an R.E. heavy duty track bar and new lower control arm bushings (Rustys), rebalanced the tires to no avail. Thats not to say it's what your problem is , but it worked for me. I just replaced the shocks cause I needed to and that turned out to be the problem, I guess. Good luck and God bless.

Yes, that is so similar to my problem... I never thought it was teh shocks because it happened even over smooth pavement. So, it looks like it is either the shocks or the LCAs.

Anyone have a part number for Bilsteins for a 3.25" lift?

BTW I will be taking pics of teh springs today.

-Chris

[Talyn]

Here are the pics of the springs that some of you wanted:
http://www.electronicimpulse.net/~vissagoth/jeep/JUimages/DSCF0088.jpg

http://www.electronicimpulse.net/~vissagoth/jeep/JUimages/DSCF0090.jpg

http://www.electronicimpulse.net/~vissagoth/jeep/JUimages/DSCF0091.jpg

Also, here is a copy of the chart that everyone seems to use for figuring LCA and UCA length.
http://www.electronicimpulse.net/~vissagoth/jeep/misc.htm
At my heigth it appears to be no reason to mess with the UCAs. I am still tossing around the idea of JKS or RE LCAs.. and preference on which one?

-Chris

[RCP Phx]

Two things come to mind!
#1-it looks like you have an aftermarket steering?
#2-Your trackbar set-up may have made the angles worse!

[Talyn]

Originally posted by RCP Phx
Two things come to mind!
#1-it looks like you have an aftermarket steering?
#2-Your trackbar set-up may have made the angles worse!

Nope, that is the factory steering. The track bar is a JKS track bar. It's frame side piviot center is about 1" lower than the stock one. However, I took an angle finder to the draglink and to the track bar (ran a piece of twine between the pivots points to get a better reading), and they were with in a degree of each other. Would that cause a wobble on a smooth surface though? I thought it would seet off a wobble over bumps only (could be part of teh problem. And since the piviot point is 1" lower than stock, wouldn't a ZJ pitman arm fix that?

-Chris

[climbon]

had same problem after I broke my tie rod down in Moab. I had it replaced with another cheap stock one to get home and I had a wobble at the same speeds you are talking about. Went with a complete Currie set up and the wobble is gone. I was told that cheap stock tie rods can flex causing wobble. The one I had to buy in Moab was lighter than my original stock one. I don't know maybe check your tie rod

[STLXJ94]

Have you thought about a bent axle shaft?

[Flowers]

Catching up on this thread. As I was reading through an old memory surfaced. Many, many moons ago I had a similar problem. I eventually discovered the nuts were loose on the upper end of the front shocks.

Is there any way you could swap shocks with one of the gentlemen that you swapped tires with? Could be worth your time.


Flowers

[Talyn]

Originally posted by Flowers
Catching up on this thread. As I was reading through an old memory surfaced. Many, many moons ago I had a similar problem. I eventually discovered the nuts were loose on the upper end of the front shocks.

Is there any way you could swap shocks with one of the gentlemen that you swapped tires with? Could be worth your time.


Flowers

Nope, one has a 4.5" lift and the other is stock. No real good way to use either of those shocks.

-Chris

[Talyn]

Originally posted by STLXJ94
Have you thought about a bent axle shaft?

How would I check for that?

[FernXJ]

I know very little about the JKS trackbar from experience. But, is it known to drop the center of the swivel(frame end) down. Have you accually measured this.
I,ve got a 00 Sport that has given me fits. Check the centering of the axle. Then from the front look at your CAs at the axle and frame(mounting points). The LCA will most likely look good. Pay close attention to the UCAs. Check to see if they may be slightly cocked to the right or the left.
Also, when I looked at my CAs after replacing with my lift I saw something bad. My right UCA was starting to wear through at the axle end. It was very, very close to tearing through!
After 2.5yrs with the lift and endless tweaking with CAs and centering with trackbar, CA sideways tilt is still not dead on.
I think that the d*** unibody is slightly not straight. You may have the troublesome type of vehicle that I've been blessed with!
Just don't get frustrated and give up. That's too easy. But, new proper length CAs and checking every mounting bolt and nut helps greatly. Bolts should be checked with not only torque but also as stated earlier(out of round)decay.
If the trackbar does drop the frame end then that also needs to be addressed. Take a tape measure and check the differences between drag. and trackbar mounting points. There is another post right now that shows their relatonship. The distance (CENTER OF THE SWIVLE POINT) at axle end of both TB and Drag should be measured from level ground. Then do the same for both at the frame end. If there is a difference between them at either frame or axle, that difference needs to be the same at frame and axle.

I know I explained this horribly, and spell like an idiot. But, somewhere in that jibberish in some tips. Wish I could show you with a pic.
Rensing

[Talyn]

Originally posted by FernXJ
I know very little about the JKS trackbar from experience. But, is it known to drop the center of the swivel(frame end) down. Have you accually measured this.
I,ve got a 00 Sport that has given me fits. Check the centering of the axle. Then from the front look at your CAs at the axle and frame(mounting points). The LCA will most likely look good. Pay close attention to the UCAs. Check to see if they may be slightly cocked to the right or the left.
Also, when I looked at my CAs after replacing with my lift I saw something bad. My right UCA was starting to wear through at the axle end. It was very, very close to tearing through!
After 2.5yrs with the lift and endless tweaking with CAs and centering with trackbar, CA sideways tilt is still not dead on.
I think that the d*** unibody is slightly not straight. You may have the troublesome type of vehicle that I've been blessed with!
Just don't get frustrated and give up. That's too easy. But, new proper length CAs and checking every mounting bolt and nut helps greatly. Bolts should be checked with not only torque but also as stated earlier(out of round)decay.
If the trackbar does drop the frame end then that also needs to be addressed. Take a tape measure and check the differences between drag. and trackbar mounting points. There is another post right now that shows their relatonship. The distance (CENTER OF THE SWIVLE POINT) at axle end of both TB and Drag should be measured from level ground. Then do the same for both at the frame end. If there is a difference between them at either frame or axle, that difference needs to be the same at frame and axle.

I know I explained this horribly, and spell like an idiot. But, somewhere in that jibberish in some tips. Wish I could show you with a pic.
Rensing

Al the bolts are good on the CAs.. i checked when I replaced all teh bushings but the upper axle ones (had no idea how to remove those but they stll felt good). The bushings did make a difference.. but it is still there. I will be checking the track bar and drag link relationship. I will be replacing the shocks with Bilseting or OMEs.. I have heard of a lot of problems with the DT3000s... if that doesn't work I will try a dro pitman arm (from a ZJ).. than the LCAs... I belive thats ome of the problems is coming from tht tires, but not all of it.. they are probably just making it worse. I can't afford to buy another car as I already took a bath when I got rid of the '93 ZJ (complete POS).. and I like this one too much and have too many mods in it already to get rid of it...

-Chris

[family XJ]

I have a wobble at those same speeds. My problem is the tires have worn a little funny. I rotate the front ones from one side to the other and sometimes it helps. I have new tires to put on tonight. Don't know if this is the answer you want or not but it's a thought. I am currently running 31 super swampers and never had this problem till they wore out. Not much help I guess but I thought I would share. Doug

[family XJ]

I just changed my tires and the wobble/shimmy is gone.

[MCgiver4x4]

i did my lift and drive my truck for a couple of month whitout problems and then suddenly one day i start to get DW at 45 mph when I hit a bump and also in plain pavement

i check al components from suspension replace tre's and get rebalanced my tires check the caster , and camber

i change the stering stabaliser for a stock new one the DW no ocurr on bumps but did on plain

i get a new one Heavy duty and the Dw gone

I hope this work for you

[Talyn]

Originally posted by MCgiver4x4
i did my lift and drive my truck for a couple of month whitout problems and then suddenly one day i start to get DW at 45 mph when I hit a bump and also in plain pavement

i check al components from suspension replace tre's and get rebalanced my tires check the caster , and camber

i change the stering stabaliser for a stock new one the DW no ocurr on bumps but did on plain

i get a new one Heavy duty and the Dw gone

I hope this work for you

Nope, thats not it