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Another death wobble thread

notamechanic

NAXJA Forum User
I know this has been beaten to the ground, and advice would be greatly appreciated. Hoping to hear from the many who have persevered this issue.

About my Jeep steering/suspension
2001 xj
4.5 short arm lift
35x12.5x17 km2
Jks quick discos
Bilstein 5100s
Rough country adjustable trackbar with about 20k miles

Newly installed cavfab 1 ton steering with heims

I installed the cav fab steering about three weeks ago. No issues or vibrations driving down the road but noticed my front tires wearing a bit after a short amount of driving. Took it in and had a 5 tire balance/rotation and a alignment done just after that. When I got my car back from the alignment shop I got severe death wobble if I hit any bump going over 30-40 mph and still have it.

I went under the Jeep and checked the torque on both sides of the trackbar and frame side bracket, lower and upper control arms, steering box, drag link and tie rod heims and everything was tight. I lowered my tire psi from 30 to 26 which helped a little. I did not remove the axle side trackbar bolt bracket yet to check for a reamed out bracket hole. But the bolt was as tight as ever so I can’t imagine that would be it.

Track bar and drag link angles are not identical but really don’t seem too far off compared to other jeeps I’ve seen. I’ll post a pic to get opinions.

Is there anything I’m missing? Anything else to check before I start throwing parts at this?
 
4dW07yv


The camera angle might make the angles look a little more severe than they really are. I’ll try and get a straight on photo tomorrow.
 
First thing would be alignment numbers? Most shops can't deal with lifted vehicles.
 
Lifted XJ's are not aligned to stock XJ specifications.

What are the alignment numbers from your report print out ?

Greater than stock toe-in is recommended, and control arm drop brackets may help achieve better alignment numbers, and will greatly improve the pavement ride and the trail performance.
 
From your pics you have a pretty large laundry list of questionable items to look at. But since you said it drove ok before the steering change, you should start there. Most alignment shops deal in "degrees" and don't understand the effects of larger tires but you need all the numbers to start with before any changes should be made from there.
Possibilities:

Bumpsteer angles

Cheap chinese heims

Were the steering arms and pitman arm drilled undersize and then reamed to the correct size or just drilled with a bit?
 
Lifted XJ's are not aligned to stock XJ specifications.

What are the alignment numbers from your report print out ?

Greater than stock toe-in is recommended, and control arm drop brackets may help achieve better alignment numbers, and will greatly improve the pavement ride and the trail performance.

Thanks for the response.

Here are the measurements

Initial
Left 1/8th
Right 3/8th
Total 1/2”

Final
Left 1/16”
Right 1/16th
Total 1/8th

I saw on Stu’s of road a good toe in for 35s was 5/32nd but a lot members here run about 1/8th.
 
From your pics you have a pretty large laundry list of questionable items to look at. But since you said it drove ok before the steering change, you should start there. Most alignment shops deal in "degrees" and don't understand the effects of larger tires but you need all the numbers to start with before any changes should be made from there.
Possibilities:

Bumpsteer angles

Cheap chinese heims

Were the steering arms and pitman arm drilled undersize and then reamed to the correct size or just drilled with a bit?



Not really experiencing much bump steer, just the dw when I hit a large bump or pothole. Unless those are related?

Cavfab states the heims are quality heat treated chromolly, but for the price of the steering I could see them being Chinese. Would Chinese ones even go bad that fast?

I used a tapered reamer to drill the holes.

What else do you see that I should go through or replace?

And thanks for your reply!
 
Have you checked the spacer on your steering box? The factory aluminum spacer likes to disintegrate with age. That was a cause of DW on my 94 back when I lived in so-cal. Replaced it with a steel spacer.

How's the caster look?
 
Not really experiencing much bump steer, just the dw when I hit a large bump or pothole. Unless those are related?

Yes

Cavfab states the heims are quality heat treated chromolly, but for the price of the steering I could see them being Chinese. Would Chinese ones even go bad that fast?

They start bad

I used a tapered reamer to drill the holes.

You mean a std tie rod reamer from the top so now they are "hourglass" shaped

What else do you see that I should go through or replace?

I can't see if you have high mis-alignment spacers on the drag link. The RC trackbar is very questionable. I see factory UCA's and " " lowers at 4.5" with no drop brackets.

What's your caster?

And thanks for your reply!
 
Have you checked the spacer on your steering box? The factory aluminum spacer likes to disintegrate with age. That was a cause of DW on my 94 back when I lived in so-cal. Replaced it with a steel spacer.

How's the caster look?

If the spacer was corroded or broken, would there be play if I tap or shake the box? As of now there isn’t. I did buy a aftermarket box bracket but waiting until I weld up my front frame stiffeners to throw it on. I can try replacing it now instead of waiting.

And I have not checked the castor. I might be able to do that tonight or tomorrow. What should the castor angle be?
 

Here is the reamer that I used
https://www.amazon.com/gp/aw/d/B0771SH4P6/ref=sspa_mw_detail_0?ie=UTF8&psc=1&th=1

Maybe I should buy some other heims? Any recommendations on quality heims?

And I’ll take photos of the heims and spacers.

I always felt questionable about the rc track bar. I replaced the ball joint on it with a moog one. Anyway I can lower the trackbar on the frame side to lessen the angles? Can’t really find a drop bracket for that. Only think I see is a ota trackbar system, but I believe I’d have to remove the passenger side upper and run long arms to use.
 
Most will say 4-7* of caster, but because I have a LP D30 and radius arms I've been running 3* going on 20yrs now.
 
Most will say 4-7* of caster, but because I have a LP D30 and radius arms I've been running 3* going on 20yrs now.

Thanks! I’ll take measurements tonight and see where I’m at. Hopefully it’s not off since I haven’t had issues prior to installing the steering.

I did just have 1 loose jam nut on the tie rod and 1 loose on the draglink. Cranked those back and will test drive to see if that’s all that’s causing it.
 
Did you check the bushings in your control arms? are the uppers still stock? they look like it in the pic. The uppers were the cause of a death wobble on one of my cherokee's
 
Did you check the bushings in your control arms? are the uppers still stock? they look like it in the pic. The uppers were the cause of a death wobble on one of my cherokee's

Sorry for the late response. Yesterday was a long one.

I have not checked but will ASAP.

My pitman arm has the slightest bit of play and makes a small clunk when I tap hard with my hand. Wonder if this might be the culprit. Just need to figure out what is causing the play.
 
When you say pitman arm, what do you mean; where the shaft enters the steering gear or the other end with the hole and TRE?
 
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