Mild Deathwobble on LJ

[Railtech]

Hello Folks,
I took the 05 LJ out today and got some mild DW at 45-50 today for the first time. Spent some time with a crowbar on the front suspension to see where I could have issue.

Swaybar Links are tight and do not flex under crowbar. No dry rot I can see.
Balljoints seem solid no lateral movement jacked up on stands.
Trackbar is tight some light deflection on axle end. Castlenut is present and pin likely from factory.
Control Arm bushings are pretty worn I can see cracks and get some deflection with the crowbar.
Tires are year old 33x10.5 BFG, will take for a free rebalance maybe 2k miles on em

Seems like on the right road surface with right conditions get some mild DW 45-50. I was on highway today at 60+ and it was smooth before the DW showed up.

LJ has 53k and is in very good condition. Has a 1" ish lift spring and blistien shocks which appear to be in good order.

I am leaning towards some control arms and replacing axle side CA bushings.

Anything else I should crowbar on or inspect before firing the parts cannon? I can get the most deflection from control arm bushings its almost 20 years old and I can bet they are OEM.

Thanks for the info, I had a TJ back in the day so had some experience swapping out arms/bushings.

 

[Danarch]

Is the DW usually around the same speed? Do you have to come to a complete stop, or almost a completely stopped before it will go away? From what I understand DW requires someone to almost stop before it will stop. If around the same speed have the tires been balanced recently? You could also swap the front and rear tires. CA bushing sound like they may need to be replaced, From what I understand people recommend rubber bushing over poly bushing.

 

[Railtech]

Thanks for the reply. Yea same speed today 45-50 I didn't have to stop to make it go away. Just go under 45. It wasn't the crap your pants death wobble I have experienced in an XJ and my old TJ. I will take to the tire shop this week for a balance. The CA bushings are shot and in need of some maintenance. Its all OEM suspension short of the small lift springs. All the steering is as well. Will try and source some OEMish rubber bushing arms. Seems as if the all I can find is cheapo chinese or some Moog ones. I likely need to do CA all the way around as they are all 20 years old nearly.

 

[L J]

Do you have to come to a complete stop, or almost a completely stopped before it will go away? From what I understand DW requires someone to almost stop before it will stop.

if it's mild, it ain't death wobble

 

[AndyG]

Swap the front and back tires and see what it does.

Ditch the crowbar and dry test the steering running and non by having someone move the steering wheel a little faster than steadily from 10-2 and watch every connection for slop as you change directions - this is testing is in action and puts force in the correct direction to reveal issues.

We got a good gang over your way so if it gets tricky we will be glad to help.

 

[JMT]

Hello Folks,
I took the 05 LJ out today and got some mild DW at 45-50 today for the first time. Spent some time with a crowbar on the front suspension to see where I could have issue.

Swaybar Links are tight and do not flex under crowbar. No dry rot I can see.
Balljoints seem solid no lateral movement jacked up on stands.
Trackbar is tight some light deflection on axle end. Castlenut is present and pin likely from factory.
Control Arm bushings are pretty worn I can see cracks and get some deflection with the crowbar.
Tires are year old 33x10.5 BFG, will take for a free rebalance maybe 2k miles on em

Seems like on the right road surface with right conditions get some mild DW 45-50. I was on highway today at 60+ and it was smooth before the DW showed up.

LJ has 53k and is in very good condition. Has a 1" ish lift spring and blistien shocks which appear to be in good order.

I am leaning towards some control arms and replacing axle side CA bushings.

Anything else I should crowbar on or inspect before firing the parts cannon? I can get the most deflection from control arm bushings its almost 20 years old and I can bet they are OEM.

Thanks for the info, I had a TJ back in the day so had some experience swapping out arms/bushings.

First, you don’t have DW unless you have to come to a stop or near stop to get it to stop (like 5mph).

Second, it sounds like you have a shimmy. Usually this is due to a tire imbalance, cupped tires, something wrong with the tire.

Third, those speeds of onset are a dead give away that the tires are imbalanced. Demand a perfect balance and have then use a roadforce machine to simulate road surface.

Fourth, do a 10-2 steering test with eyes underneath to see if there are any components permitting the tires to shimmy.

 

[TheBoogieman]

mild DW

Oxymoron.
: a combination of contradictory or incongruous words

 

[Coadster32]

I do agree with the tire rotation and balance. Might have them done anyway. Sounds like C/As are in your near future.

A couple/few ideas for you to check as well.

You could check the toe of the front end, as your tires may want to "drift" if they are toe out.
Another easy check is to lift up one tire off the ground, and check for wheel bearing/steering linkage play.
And lastly is to take the track bar out, and see if it made an elongated slot out of the hole in the frame. It may be tight, but also may be moving while under load.

 

[Railtech]

Thanks for all the replies folks. I finally got a helper to apply brakes while turning the wheels where they just turn. There is an good bit of slop in my track bar to frame joint. It looks tight and right but when force is applied there is a good bit of shift in the joint when loading each way. The bushing side has some slop there where the bushing is degraded. Track bar on order and I will replace the control arms as maintenance. Tie rods and drag links look good and no slop there. I think with the track bar and CA I should be in pretty good shape. Should have the parts tomorrow and I will get a rebalance. Likely will get alignment too as it has not had one since I have had it for 4 years or so. Appreciate all the feedback!!!

 

[AndyG]

Thanks for all the replies folks. I finally got a helper to apply brakes while turning the wheels where they just turn. There is an good bit of slop in my track bar to frame joint. It looks tight and right but when force is applied there is a good bit of shift in the joint when loading each way. The bushing side has some slop there where the bushing is degraded. Track bar on order and I will replace the control arms as maintenance. Tie rods and drag links look good and no slop there. I think with the track bar and CA I should be in pretty good shape. Should have the parts tomorrow and I will get a rebalance. Likely will get alignment too as it has not had one since I have had it for 4 years or so. Appreciate all the feedback!!!

If you count there are over 40 bushings under these and there is no question that they will eventually fail-

In a nutshell this is why a well-built rig feels really tight and predictable and most old ones feel very vague and loose.

With the right work and good parts these things can be remarkable.