JK death wobble

[snoik]

I'd heard about it, but never experienced it until now and don't want to again.

On my way home from the Mudgee Field Days on Saturday I came across a friend of mine broken down and parked in a bad location, so I dragged him off the road, he'd done UNI on the tail shaft and had another one on the way to change out(he's got an old rodeo)
I left him as he had someone coming to assist and headed home, got up to about 80kph and next thing the whole front of the JK was shaking and wobbling all over the place, a very scary experience, I pulled over and checked under the thing, but nothing stood out, so started driving again, same thing happened again shaking and wobbling, stopped and got under again and still couldn't see anything??

Started driving again and nothing, no shaking or wobbling and hasn't done it since??
once I got home I jacked it up, checked wheel bearings, play in bushes etc, still nothing??
There must be a bit of paly in something but I can't find it.
I don't want to go and replacing everything(bushes/ball joints/tie rods) because you won't know what actually fixed it.
Is there any tricks that could determine the issue

Any idea's

Andrew

[XJeepers]

Get someone to turn the steering left and right with the vehicle on the ground whilst you have a look at the trackbar bushings.


Sent from my iPhone using Tapatalk

[snoik]

Thanks,
I'll give that a go when I get home from work, I did get another steering Damper as the old one was leaking, I thought that would be the starting point, I've been told the steering damper will only mask the real problem.

[snoik]

Thanks XJeepers,
good call having someone to turn the steering with the vehicle on the ground, I did it the same but with the front in the air on stands, and couldn't see anything, on the ground works and showed me where the play is, and you are right, top track bar bush has about 5mm play, so I get new ones in the mail on Monday.

[XJeepers]

[emoji106]


Sent from my iPhone using Tapatalk

[Dave]

I'd suggest a chat with SteveF at the next meeting. His preferred fix method is to add a caster correction bracket to lower the front control arms where they meet the chassis (if you have raised the vehicle)…

His post #35 on his build page “Got some Death Wobble after the lift to 3" so, after my experience with the XJ, went straight for the AEV caster correction brackets. That top right hand bolt is a real pain with the exhaust in the way but I managed to get it out by jacking up the right hand side of the engine a little and then levering the exhaust out of the way. Anyway, drives solid as a rock again now. Here's a quick pic, from left to right, stock, lifted 3" and with occasional DW, 3" with AEV drop brackets and back to riding like stock (better actually)” http://www.sydneyjeepclub.com/showthread.php?4518-Steves-JK/page4

Other members have other fixes, dampers, track rod ends, bushes… but he is pretty confident that this is a good place to start.

Good Luck,
Dave

[snoik]

ordered the bushes last Friday through Repco, so I pushed the old ones out ready, they turned up yesterday, and guess what, they don't fit(too small) rang Repco back and told them, the bushes they supplied (white Line brand) is the only listing they have, so took them back, got a refund and ordered some on ebay. so now the only vehicle I have is parked up with no bushes at all.
luckily my boss lent me a work vehicle in the meantime.

[Dave]

https://www.morris4x4center.com/catalogsearch/result/?q=bushes first place I look for parts...

[Dru]

When you get it all back together get a wheel alignment done. Chase as much caster as they can squeeze into it.

[Elio S]

I had this problem on my WG Grand Cherokee when I owned it. If I touched the brakes at 80km/h it went into a severe death wobble that could only be stopped by bringing the car to a complete halt. It was that bad, the first time it happened my wife and child that were in the car were in tears as they thought they were going to die. I went through checking the front end. Couldn't find anything wrong with any of the bushes, everything was tight, I replaced all the tie rod ends and dampener anyway, but still the problem persisted. Next, even though they had no play, I was going to replace the ball joints. I only fixed the problem by chance when I replaced the tyres. It had Pirelli highway terrain tyres on it which were still in great condition, but I installed BFGoodrich mud terrains to it, and the problem disappeared. Visually the Pirellis were still in great condition, but for some reason they caused the problem. I think the only way to check the tyres to see if they're the problem is to swap it with another set off a car that isn't faulty and see if that does the trick. Funnily enough, death wobble is one problem my TJ has never had. It's got a 4" lift, standard arms, and flogged out bushes and shocks, yet it's still drives fine. Go figure. Hope you get it sorted

[snoik]

finally got the new bushes(correct size this time) but in the meantime while waiting for the bushes I replaced all 4 ball joints with heavy duty Synergy units, (the bottom 2 were really loose?) also replaced the drag link with a heavy duty Synergy unit, and steering damper from teraflex with relocation bolt which replaces the bottom track bar bolt.
All seems OK with no more death wobble, just a shake like wheel balance, so getting the tyres checked will be next, but it's definitely better.
Andrew

[snoik]

finally got a wheel alignment, and there's no adjustment for caster, the steering is really sensitive/ touchy (flighty?)looking on the net, adjustable control arms seem to be the go, can I get away with only installing lower front adjustable control arms, or will I need to replace all top as well.
I have replaced the steering linkages with Synergy units so was looking at the Synergy control arms from SBR.

any advice
Andrew

[XJeepers]

Bottoms only should be fine if your lift is south of 4”.


Sent from my iPhone using Tapatalk

[snoik]

I was told it has a 3.5" lift, so bottoms only will work then?

[XJeepers]

Yep [emoji106]


Sent from my iPhone using Tapatalk

[XJeepers]

Only really need adjustable uppers and lowers to dial in wheel base at taller lifts. Adjustable lowers (or uppers) to manage caster is all that is really needed. I prefer lowers due to ease of adjustment, but others will suggest adjustable uppers are a better choice. Either way, you will be able to adjust the caster with uppers or lowers.


Sent from my iPhone using Tapatalk

[snoik]

thanks for the info

[snoik]

Finally put the adjustable lower control arms on, and WOW, what a difference, should nave done it sooner.