Death wobble Q's

[XJEEPER04]

Ive replaced everything on the front end that would cause a death wobble....to my knowledge and i still have a wobble. Ive got control arm bushings and a hole new trac bar and it still does it???anyone got any idea's???any inout is great. Ove been battling this wobble for six months and dishes out a tone of money so im willing to try about anything

[Eagle]

Please describe your wobble. Severity, circumstances that trigger it, speed of vehicle, what you have to do to control/stop it. You're not giving us much to guess at here.

[XJEEPER04]

sorry starts at about 45 and it feels like the front end is going to come out from under my jeep. if i brake to below 45 then it stops, also it doesnt do it on gravel roads. and if you put your head ot the wondow when its doing it...you can see the tires wobbling

[Eagle]

Do you have any sort of lift? When did you last have an alignment, and what are the alignment settings?

[XJEEPER04]

no lift, and it hasnt been aligned?? would that do it?

[Eagle]

The five most critical factors affecting death wobble (IMHO, and in my opinion of importance, which others may dispute) are:

1. Wheel Balance

2. Wheel Balance

3. Wheel Balance

4. Caster Angle (alignment)

5. Toe-in/out (alignment)

[Eagle]

Did I mention wheel balance?

[CheapXJ]

Considering that it only does it on pavement... I'd suspect that it's toe.

can you accelerate through the wobble? say, for instance it will stop at around 50mph?

[ssnsltd]

Exactly what have you replaced?

I have (I think) just fixed mine

[XJEEPER04]

yes, somtimes if im on the gas just right or im on a really smooth highway i can get it upto highway speed. ive replaced the trac bar and bushings and the control arms and bushings tires and wheels but they arent balanced to my knowledge

[ssnsltd]

Have you replaced the steering stabilizer/damper?

FWIW:
Before I started changing things out, mine had gotten so bad hitting a mouse turd in the driveway set it off.

First I replaced all of the rubber bushings in the front suspension. That got me back to having to hit RR tracks or a good size pot hole to start the kabuki dance.

I didn't think the stabalizer was bad until I bought a new heavy duty one. I have been driving the truck for a week without even a shimmy.

[Eagle]

Originally posted by CheapXJ
Considering that it only does it on pavement... I'd suspect that it's toe.

Despite my tendency to blame it on tire balance (which I still think is the first thing anyone should check), tires would be unbalanced on gravel as much as on pavement. Gravel being more "slippery" to the tires, if the toe-in is set wrong it would have less effect on gravel than on asphalt.

[XJEEPER04]

would a bent tie rod cause the problem?

[CheapXJ]

Originally posted by XJEEPER04
would a bent tie rod cause the problem?

It sure wouldn't help!

[Eagle]

Originally posted by XJEEPER04
would a bent tie rod cause the problem?

A bent tie rod would result in a shorter distance between the two ends, which translates into increasing the toe-in.

[XJEEPER04]

eagle.....your great

[XJEEPER04]

but one time my jack did slip off of the axle and bent my tie rod a but...this may be my problem... i am know in the process of tighening my trac bar and mount and after that i will straighten my tie rod and see what the turnout is and ill let you guys know...thanks

[Yucca-Man]

I just started playing the DW game this week, after ditching an RE 2" Budget Boost in favor of their 4.5" SuperFlex kit. The first drive home (65 miles) was good with only one minor instance of DW at about 65mph when the road surface changed and the front passenger wheel dropped. Letting off the gas and slowing under 50mph "cured" it and it didn't reoccur.

I made the mistake of getting the tires rotated and balanced at Big O Tires today, and in my second drive since the lift found that I couldn't go over 60mph without wobbling so bad I almost went off the road. Accelerating through it isn't something you consider when the front end is dancing like Michael Jackson with his hair on fire...

I have lifetime rotate and balance on the tires through Big O and will have another store recheck everything tomorrow along with getting the alignment rechecked.

Here's what the lift entailed:


Adjustable LCA - 16" (stock is 15.75") this is per several writeups, and matches the length of the non-adjustable LCA
UCA - the RE UCA is the same length as stock, but I replaced that this evening anyway
Trackbar - Installed the Extreme-Duty Trackbar and although we seem to have forgotten to torque it, I still had DW after torquing the trackbar
Transfer case drop. I hated to lose the ground clearance, but installed the 1" t-case drop which at least helped resolve vibes between 20-35mph
Coils. Removed the stock coils and 1.75" spacer, now running 4.5" RE coils


If the balance and alignment doesn't resolve this, what about the drop LCA brackets? They would at least bring the LCA angle closer to horizontal again...

[XJEEPER04]

eagle, how exactly do i check my toe-in i know it can be done with a tape but im really not to sure how to do it?

[ssnsltd]

Maybe I am missing something.

Say the balance and the alignment is/are off. I agree that having that corrected is a good thing but, that would only keep the wobble from happening more often. In order to stop it forever, the part or parts that hold the axle in place (that is/are no longer doing this) must be fixed.

[Eagle]

Originally posted by XJEEPER04
eagle, how exactly do i check my toe-in i know it can be done with a tape but im really not to sure how to do it?

Basically, find the centerline of the tire tread. Now take a tape measure and measure between the centerline of one wheel and the centerline of the other at the front of the tires, with the tape held up as close to the axle centerline as you can get it.

Now repeat this measurement with the tape held behind the wheels. If you can't get both measurements at the height of the axle, drop down until you can get both at the same height.

The difference between the two meausrements is the toe-in or toe-out. If the forward measurement is larger, the tires are toed out. If the rearward measurement is larger, the tires are toed in.

The FSM gives toe-in specifications, and they have changed slightly over the years. In general, you want to have zero toe-in when the tires are rolling forward. Since there is usually some "slop" in the steering linkage, the initial setting is ususally adjusted to about 1/16" toe-in.

The newer FSMs and the print-outs you get from most alignment shops now give it in degrees rather than inches. However, doing at home you probably won't have a tape measure calibrated in degrees. Zero is zero in any system of measurement, however.

[Eagle]

Originally posted by ssnsltd
Maybe I am missing something.

Say the balance and the alignment is/are off. I agree that having that corrected is a good thing but, that would only keep the wobble from happening more often. In order to stop it forever, the part or parts that hold the axle in place (that is/are no longer doing this) must be fixed.

If there is no wobble, there is no need for everything to be super tight to resist it. My '88 still has the original ball joints, tie rod ends, drag link ends, and steering stabilizer. I have no death wobble. Alignment is to stock specs and tires are balanced.

The parts holding the axle in place are only covering up the symptoms. If you really want to stop death wobble, you have to prevent the wobble before it starts, not rely on new parts to try to grab it by the throat and strangle it to death. The answer seems to lie with balance and alignment. If those are A-okay, your steering components can be loose as a goose and you won't have death wobble.

[XJEEPER]

Originally posted by XJEEPER04
Ive replaced everything on the front end that would cause a death wobble....to my knowledge and i still have a wobble. Ive got control arm bushings and a hole new trac bar and it still does it???anyone got any idea's???any inout is great. Ove been battling this wobble for six months and dishes out a tone of money so im willing to try about anything

Stop using a twisted version of my alias and I'll make your DW stop........(could be Jeeper vodoo......... you never know) :confused:

[ssnsltd]

FWIW:
After looking on several sites and searching for other people working on the DW, and having worked through the problem on my own vehicle, I respectfuly disagree.

Almost everything I read on DW (I am not talking about the vibrations or the little shimmy some folks have after putting big tires on) the way it starts is the truck hits an object. A pothole, RR tracks, manhole cover, etc.

Tire balance, alignment, under or over inflated tires sure as heck don't help, but neither are they the cause or cure.

I have an 87 and an 88. The 87 is out of alignment and since I took all of the weights off the tires, out of balance. I have never had even a hint of DW, no matter what I hit.
On the 88, the first thing I did was have it aligned and the tires balanced, it had no effect on reducing the DW problem. Only when I replaced the worn parts that held the axle in place did the problem go away.

[XJEEPER04]

well, i tightend the trac bar, and straightend out my tie-rod and for the most part the death wobble is gone!!!!!!! I am still going to adjust my alignment and balance the tires. I bet after i do this it will ride like it is bran new.....thanks for the help

[gr8tires]

This is good information for me. I'm going to look at an MJ soon, and the owner says it vibrates terribly above 45.
XJEEPER04 keep us posted on final outcome.

[ssnsltd]

XJEEPER04, you didn't mention if you checked/ replaced your steering damper or not.

I finaly got a chance to test the jeep after I replaced the last upper suspension bar bushings and put on a heavy duty steering damper. I took the jeep for a drive over the double RR tracks that have always set my 88 off even at 20mph. I drove over them at 45, 55, and 65mph. No DW.

[XJEEPER04]

Guys....i straightend my tie-rod and put a washer on my trac-bar where it mounts to the unibody, then put some balanced wheels on her and she rides fine no more death wobble:D

[Yucca-Man]

Add my vote back into the "balance means a lot" group. After tightening the trackbar mount, DW was minimal but still occurred. I made the mistake of going to Big O to get the tires rotated and 'balanced' and DW came back with a vengeance above 45-50 mph.

Without changing anything else on the Jeep, I pulled off the 30" BFGs and dropped in 32" BFG ATs on AR767 rims. DW is almost gone although I do have an occasional shimmy after hitting bumps at speed.

Did the tires cause DW? No, since they are the same ones I had on for over a year with no problems.

Does that mean the suspension changes caused DW? That's very possible since I had just replaced the springs, trackbar, swaybar and control arms and they are now operating at different angles and require a fine-tuning alignment to be "correct"

Jim