a question about death wobble

i am having some problems with death wobble. i have a 99 xj, 4.0, aw4, np231 w/ sye, 3" lift, adjustable trackbar. i was running 31x10.50 bfg's with no problems. then i put a sets of stock wheels on (225's) and reinstalled the swaybar for my long trip to NH. when doing over 50 MPH when i hit any type of uneven bumps (bridges very specificaly) i get death wobble like mad.

all the tie rods are new. ball joints are good. the track bar TRE had a little play so i replaced it and still death wobble. the steering damper is still new-ish...

so i have 2 questions.. can JUST bad/out of round tires cause death wobble alone?they dont feel out of balance.

my LCA's are 16.5" long (the ideal length for 4.5") and i am only lifted 3". is it likely that this could be causing death wobble? too much caster? they are fixed LCAs and i cannot shorten them any more on the frame side.

i will be putting the 31 BFG's on later today but i wont have a chance to do any serious hwy driving for a couple of days.

thank you in advance for any help and suggestions.

idk about "out of round" causing wobble, but out of balance will give you DW symptoms like you are describing. just for my .02, i have found that some shops only place weights on the inside of the wheel (to look purtier i spose) and this can be a problem in balancing, at least it was fro me...drove me nuts until i had a shop do it right. since ur rig was fine until you changed tires/wheels you know the prob is in your tires/wheels; mite wanna have a look at balancing...possibly a bent wheel?

Yes, and yes.

It doesn't matter what's not right, whatever it is needs to be changed. If everything else is OK, for sure, then you have to consider what's left. Too much caster can be a problem, and tires can be a problem. If it didn't have DW with the other tires, then tires must be a major consideration.

Otter said:

idk about "out of round" causing wobble, but out of balance will give you DW symptoms like you are describing. just for my .02, i have found that some shops only place weights on the inside of the wheel (to look purtier i spose) and this can be a problem in balancing, at least it was fro me...drove me nuts until i had a shop do it right. since ur rig was fine until you changed tires/wheels you know the prob is in your tires/wheels; mite wanna have a look at balancing...possibly a bent wheel?

Click to expand...

If you wheel your rig, then you only want weights on the inside. On the outside they will just get knocked off with rocks and roots and stuff.

Do a front end alignment on it. You can do it in your drive way with simple hand tools. Check your caster and toe put them to spec and then check your track bar bushing. Then get your tires balanced. If that doesn't work use the other tires an throw those away.

In my fight with death wobble it was bad tires the whole time. Out of balance and a failing belt. If you put your old tires back on and it goes away you have your answer. Could also try just moving th eback tires to the front instead.

"If you wheel your rig, then you only want weights on the inside. On the outside they will just get knocked off with rocks and roots and stuff."

Good point Goatman, hadn't thot about that, ty.

Try tire pressure? I was a couple pounds low(actually like 8) on my left front and it gave me DW. aired up right and it went away instantly.

ok well i put the 31's back on. its at least more pleasing to the eye... i havent had a chance to get it up to 55+ and hit a good bump but i will let you all know what happens.

if i still get DW then i guess il start looking for adjustable LCA's. i am still running stock uppers. would it be better to get adjustable upper control arms to correct caster? keep in mind im still at only 3" of lift.

sounds like a lot of bumpsteer. check all your tierod ends and bushings, check that your trackbar and draglink are as close to being parallel to each as possible. check ball joints. all can be causes.

dylan1650 said:

ok well i put the 31's back on. its at least more pleasing to the eye... i havent had a chance to get it up to 55+ and hit a good bump but i will let you all know what happens.

if i still get DW then i guess il start looking for adjustable LCA's. i am still running stock uppers. would it be better to get adjustable upper control arms to correct caster? keep in mind im still at only 3" of lift.

Click to expand...

You should have caster adjustment on you lowers at the frame mount. That is how it's done in stock form. The main bolt slides forward or backward with the adjustment nuts on the back of the mount. I'm at 3.5 and I have drop brackets fixed lowers and adjustable uppers. It's all just how much flex you want really. Stockers don't give you much.

I went with fixed length lowers (16.5") and used adjustable uppers, it's all the same as long as there is adjustment available. The stock lowers already have a small amout of adjustability anyway.

Caster shouldn't be an issue in this case. I have 2.5"- 3.0" lift on 31s with adjustable LCA. s set at 16.25" with no trouble. With to much caster you should get driveline vibration from an exaggerated pinion angle though.


If the Ball joints and TREs are good like you said and nothing else is worn out Id say it has to be the tires.


If you still have DW when you go back to the BFGs I'd do a good inspection on your hubs and UCA bushings. Double check the track bar bolts too


Do a Driveway Alignment for sure. Its EASY!!!

Don't make the mistake I did and do it with the wheels off the ground and the Jeep supported by the chassis.


No no no bad bad bad

Waleyed XJs gandle like crap.

well guys i put the BFG's on and still DW. i had an alignment shop adjust the toe a few months ago and have made no sugnificant changes to the front suspenion since. (dont ask me why i didnt have the caster checked at the time) the frame mounts are adjusted all the way back and both hubs have no play in them. as far as the track bar being paralell with the drag link it is hard to tell cuz it is one of them trackbars with 2 bends in them.. ya know the ones shaped like IRO's track bar. to be honest i have no idea who made the track bar cuz i bought off of a friend. all i really know about it is that it uses an ES140R tie rod end and had no problems upon installing months ago. i have no drop pitman arm or anything else that would change the geometry in such a way. as best as i can tell the trackbar is almost paralell with the drag link.

so next i will be checking the torque on all the bolts related to the front suspension.

i never considered that it didnt happen until i reinstalled my front sway bar but i refuse to believe that that had anything to do with it.

it should be noted that the front pinion is almost paralell to the ground. (to give everyone a ball park indication of what the caster angle is) i put a level to the flat spots on the yoke and its almost level.

for that reason i almost want to point my finger at the caster without a doubt but i had no problems for a couple months upon installing the LCA's. and these lower control arms for a "3-4.5 inch lift".

these are the exact LCA's i purchased


http://www.ebay.com/itm/Jeep-Cherok...Parts_Accessories&hash=item3cbd447db1&vxp=mtr

maybe i installed them in the wrong direction? short side toward the axel right???

i bought the same arms, from the same guy, but mine came measuring 16.5" eye to eye (no that tahat's a big deal)

they go like this



i've got a rusty's trac bar, on a fatbob's relocation bracket, with stock steering and my front axle is shifted to the driverside 3/4" as I have yet to fix it, my castor is almost right (probably 4 degrees) and my tie rod ends need love as do my ball joints (but I;'m planning a WJ swap next month - this month is the 4.56 regear) ...
... what does this all have to do with it you ask?

I have no DW whatsoever ... when I did it was either my tires or my rims (traded them for my ZJ brake parts just to get rid of them) I got tired of tying to rebalance tires that were done.

yes devilfrog my LCA's are 16.5" from eye to eye as well. but it appears that i have too much caster @3" of lift with the caster adjustment shoes as far to the rear as possible... im having front driveline vibrations as well... i just dont know... im going crazy. i wish i had an angle finder. what lift height are you at? is there supposed to be any angle in the front driveshaft?

I'm at 5.75" on the front but I also have adjustable uppers as well. With the stock uppers I had horrible handling.

ok so i had town fair tire "align" it, balance the front tires and replaced the steering stabilizer with an OEM one.. according to the sheet my caster is 10.5* positive. as far as i know the death wobble is now just a shimmy. i guess i just dont understand how too much positive caster can cause DW/shimmy. i certainly understand how too little caster can. so i guess i will be shopping around for adjustable uppers or lower control arms actually made for 3 inch lift.