Really Death Wobble

SmokeyJoe101

SmokeyJoe101

Member
I have a Sahara currently on the stock wheels/tires. I put a 2” Dynatrac Lift with the Dynatrac FLC arms. I also replaced the Track Bar F & R, the Drag Link and the Tie Rod all are Synergy brand. I put a Fox Stabilizer on as well.

Took it out for a test drive and around 20-30 I can hear what sounds like a rubbing noise over dips in the road. The I took it on the HWY and all was well then I hit a expansion joint going over a bridge and the front end shook violently and I had to slow down to about 15MPH for it to stop.

Any ideas on what to begin looking for?

I am so ticked off at myself this moment!
 
Last edited:
SmokeyJoe101 said:
I have a 2024 Sahara currently on the stock wheels/tires. I put a 2” Dynatrac Lift with the Dynatrac FLC arms. I also replaced the Track Bar F & R, the Drag Link and the Tie Rod all are Synergy brand. I put a Fox Stabilizer on as well.

Took it out for a test drive and around 20-30 I can hear what sounds like a rubbing noise over dips in the road. The I took it on the HWY and all was well then I hit a expansion joint going over a bridge and the front end shook violently and I had to slow down to about 15MPH for it to stop.

Any ideas on what to begin looking for?

I am so ticked off at myself this moment!
Click to expand...
You should first double check torque on the track bars.
 
SmokeyJoe101 said:
I have a 2024 Sahara currently on the stock wheels/tires. I put a 2” Dynatrac Lift with the Dynatrac FLC arms. I also replaced the Track Bar F & R, the Drag Link and the Tie Rod all are Synergy brand. I put a Fox Stabilizer on as well.

Took it out for a test drive and around 20-30 I can hear what sounds like a rubbing noise over dips in the road. The I took it on the HWY and all was well then I hit a expansion joint going over a bridge and the front end shook violently and I had to slow down to about 15MPH for it to stop.

Any ideas on what to begin looking for?

I am so ticked off at myself this moment!
Click to expand...
as mentioned, double check the torque on the track bars and if you still have the stock stabilizer, put it back on.

think of anything else you may have loosened and forgot to tighten (been there)

did you tighten/torque track bars, control arms while on the ground? if not, loosen the, bounce the bumper a few times to eliminate any binding then tighten/torque while on the ground.
 
jeeeep said:
as mentioned, double check the torque on the track bars and if you still have the stock stabilizer, put it back on.

think of anything else you may have loosened and forgot to tighten (been there)

did you tighten/torque track bars, control arms while on the ground? if not, loosen the, bounce the bumper a few times to eliminate any binding then tighten/torque while on the ground.
Click to expand...
Garbage man came today and took the stabilizer, maybe I could remove it all together while troubleshooting shooting.
The rear track bar was tightened on the ground. I did not loosen the control arms in the rear when I put the new springs in, I forgot.
The front all got tightened with the axle on jack stands. Although I feel like I may not had gotten the right torque on the lower control arms. I used red loctite and I think it dried way before I torqued them. Not sure if this is OK or not, but thinking back on it seem it may not be?
 
SmokeyJoe101 said:
Garbage man came today and took the stabilizer, maybe I could remove it all together while troubleshooting shooting.
The rear track bar was tightened on the ground. I did not loosen the control arms in the rear when I put the new springs in, I forgot.
The front all got tightened with the axle on jack stands. Although I feel like I may not had gotten the right torque on the lower control arms. I used red loctite and I think it dried way before I torqued them. Not sure if this is OK or not, but thinking back on it seem it may not be?
Click to expand...
You're correct, you should have loosened all the control arms and torqued them while on the ground, not jackstands.

With the Jeep on the ground, loosen the control arm bolts, bounce the bumper a few times then torque them, apply Loctite to each nut/bolt as you are ready to torque them - check the nuts, if they are stover nuts they won't need Loctite, also use a paint marker to make a witness mark and you can easily check them every few months to see if they have loosened.

leave the stabilizer on at this point.
 
SmokeyJoe101 said:
I have a 2024 Sahara currently on the stock wheels/tires. I put a 2” Dynatrac Lift with the Dynatrac FLC arms. I also replaced the Track Bar F & R, the Drag Link and the Tie Rod all are Synergy brand. I put a Fox Stabilizer on as well.

Took it out for a test drive and around 20-30 I can hear what sounds like a rubbing noise over dips in the road. The I took it on the HWY and all was well then I hit a expansion joint going over a bridge and the front end shook violently and I had to slow down to about 15MPH for it to stop.

Any ideas on what to begin looking for?

I am so ticked off at myself this moment!
Click to expand...
The Dynatrac lift I tested yielded just shy of 2" of actual lift once the springs settled. This is actually within factory tolerances and loosening up and retightening the control arm bolts should not be necessary. Always a good idea to do when installing a lift and retaining factory arms but again, not critical with this small of a lift.

If I could put my finger on the problem, it'd be your Fox steering stabilizer. On a JK, I would say what steering stabilizer you run shouldn't make a difference or running one at all for that matter but on a JL or JT, the electric steering pump does some funny things. Even on a bone stock JL or JT, without the OE stabilizer, you can get wobble and I have seen it for myself. Nothing short of OE or, what I have found, the Rancho RS7MT helps to keep that wobble in check.

Otherwise, I would defer to what has already been stated and that is to triple check your front track bar bolts to make sure they are tightened to 120 ft bls of torque. Typically, that is the number one cause of death wobble.
 
Thanx for everyone’s guidance and thoughts so far.

I loosened all the front LCA and torques them on the ground. I cleaned the threads and applied the loctite right before tightening each one. I had one bolt that was creaking like hell while I was tightening it. The torque wrench made it to 190ftlbs and looking at the other side it had the same number of threads exposed. I verified torques on all bolts involved in the lift and steering all were good.

Went for a test drive and the same expansion joint caused the death wobble again.

I am going to try to make time for an alignment tomorrow, I think I read somewhere an alignment problem can cause this.
 
So I decide to remove the Stabilizer and replace the LCA bolt that came with it with the OEM one. Still wobbles.

I don’t get it though it rides really nice, no wondering, straight as an arrow down the rode hands free, no shakes or weird vibrations just this insane wobble tonight I thought I was gonna go off the rode it pulled very hard left while the wheels were doing their thing.

I don’t have much hope but I am going to get the alignment done tomorrow and maybe a second set of eyes they will see something.

When I get the Jeep back, I will post some pictures, maybe somebody can spot something
 
Test the knuckle ball joints for play before re-torquing. Do re-torque them afterwards. Worn/loose/damaged ball joints will cause DWs.

Check the steering box for loose or broken bolts and the frame where it mounts for cracks.

After troubleshooting my brother’s JLU when it had DWs, I suspect the track bar flexes and sets up a harmonic vibration without a steering stabilizer to damp it. It’s my belief a stouter track bar would resolve this issue.
 
GP NOIR said:
Test the knuckle ball joints for play before re-torquing. Do re-torque them afterwards. Worn/loose/damaged ball joints will cause DWs.

Check the steering box for loose or broken bolts and the frame where it mounts for cracks.

After troubleshooting my brother’s JLU when it had DWs, I suspect the track bar flexes and sets up a harmonic vibration without a steering stabilizer to damp it. It’s my belief a stouter track bar would resolve this issue.
Click to expand...
Are you talking about the knuckle ball joints, this is a 2024 with about 10K miles on it. At this point I will check anything. I did look at the steering box bolts and torqued them to 99lbs if memory serves me.
The Jeep has the synergy track bar that I just installed.
 
A lot of good advise has already been given on where to start. I have to agree that something is loose or has play. I would look a t tire balance but sounds like it started after installing new parts. Based on your lift height, I'd assume you didn't do a draglink flip/drilling the knuckle. Being that you have aluminum knuckles and changing the rod ends/taper of the rod end, make sure you don't have play in the draglink at the knuckle. The aluminum knuckles CAN oblong open creating movement. This happens more so with balljoints but worth a check.

If you have someone available, with the jeep on the ground, start the vehicle and have some rapidly/short movements turn the steering left and right. Do this while you are under the Jeep looking at the steering looking for any movement AND put your hand on the components to see if you can feel any "popping" or movement.
 
SmokeyJoe101 said:
Are you talking about the knuckle ball joints, this is a 2024 with about 10K miles on it. At this point I will check anything. I did look at the steering box bolts and torqued them to 99lbs if memory serves me.
The Jeep has the synergy track bar that I just installed.
Click to expand...
However small the chance the ball joints are loose/worn/defective with just 10k on the clock, the chance is never zero. As Jeremy pointed out in his post above, something is loose/has play. Take nothing for granted.

If the Synergy track bar is beefed up, it shouldn’t flex. If made to OEM specs, it might and the steering stabilizer is strongly recommended.
 
wayoflife said:
If I could put my finger on the problem, it'd be your Fox steering stabilizer. On a JK, I would say what steering stabilizer you run shouldn't make a difference or running one at all for that matter but on a JL or JT, the electric steering pump does some funny things. Even on a bone stock JL or JT, without the OE stabilizer, you can get wobble and I have seen it for myself. Nothing short of OE or, what I have found, the Rancho RS7MT helps to keep that wobble in check.
Click to expand...
I followed Eddie's advice on this (different thread). I had originally been reimbursed, very early on, by FCA for a Fox TS stabilizer through the TSB. I stuck with it, and it worked fine on 34.75" tires on stock suspension. When I went with 37s and a 2.5" lift, I got some pretty good wobble. None of the normal stuff fixed it: upgraded ball joints, metal cloak tie rod and drag link, rusty's track bar brace, shouldered trackbar bolts. They did nothing. The Rancho RS7MT was the easiest swap (both technically and easy on the wallet) and has eliminated the wobble and bump-steer.
 
Here is the alignment sheet. So test drive - expansion joint that got it started did not, the next expansion joint down the road a bit further did.

It happens almost every time at 55mph. Getting ready to throw the baby out the window
 

Attachments

  • IMG_3713.jpeg
    IMG_3713.jpeg
    140.8 KB · Views: 24
Last edited:
You must log in or register to reply here.
Top Bottom