Death? Wobble

[Aaron]

Hey all,

I have an issue with the JK I wanted to throw at you all. I have an oscillation that happens in the steering of the JK if you were to hit a bump right between 23 and 33 MPH. People get all freaky about what you call death wobble and not death wobble so I am hesitating. However, this wobble, once started, will not stop unless you get out of that speed range and the vehicle is pretty much not steerable.

I have read many articles and the issues is mostly caused by issues with the track bar or with not loosening the bolts on the control arms and/or track bar when lifting your vehicle. I had done all those things when I lifted the vehicle, however, I did them again to make sure there was no binding. Some people say put on a stiffer stableizer or adjust the caster. Most people say these are things which just mask the problem by tightening up the steering.

I have a theory but I am not sure... Take a look at the pictures below. This is one of my front lower control arms mounting points (yes the other is the same). Notice that the rubber bushing does not extend all the way to the edge of the mount. The stock ones did. So, between the mount arms (?) is the sleeve. Since the sleeve has the rubber bushing between it and the actual control arm, couldn't this cause a side to side oscillation that could end up being death wobble? Or are these bushings too stiff to allow such things?

[Aaron]

One other thing I just noticed in the pictures...There is a place where mud has been rubbed off in that top picture. I just went an looked at all the other mounts. There is no such rubbing going on. This leads me to believe that this CA bushing is allowing the control arm to move back and forth? Would you all agree?

[Hypoid]

If the sleeves are clamped tight in the frame bracket, check the bushings for wear and tear. Are these Poly bushings?

Correcting the castor is not a band-aid because lifting changes that angle from stock. When I first did my BB, the steering would "hunt" every time I hit an expansion joint on the highway. Also, the steering would not re-center on it's own.

[Aaron]

These are new control arms from the lift so the caster was changed when lifted and the steering does auto center very well. see the picture for the difference in the length of the lower control arm. In the picture, the other end of the control arm is resting with the mounting bolt in the mounting hole so the comparison is close. This was a 3.5" lift.

Its hard to tell from the picture but the new control arm (round) is about 1/4 to 3/8 inch longer than the stock one (square). Also notice the rubber bushings on the stock control arm go all the way to the edge of the sleeve which would not allow as much side to side motion? I think this might be where the issues is. Opinions welcome!

[WINKY]

one would think there should be no lateral movement on those control arms. I know ram trucks have an issue with the steering box getting loose from the frame or the trackbar is worn or putting the driver side spring on the passenger side. sometimes combination of things screw stuff up...

[Brad]

You should have no lateral movement in that arm. Any stress is going to lead to excess wear on the Bolt/Arm. Seeing as you not only have a lift but bigger Tires putting extra stress on the suspension I would see if someone has come up with a remedy. Possibly on a Jeep forum.

[MelloYello]

How does your track bar look? Is it the stock one or did your lift come with that too? If it is stock, I would look in to a HD replacement. On my XJ, I had the wobble around 45-55 mph, I replaced the stock track bar with a JKS Heavy Duty one and it has not wobbled since. ??

[scout man]

I would say yes, that gap should not be there (as least not as large). As a way to see if that is the problem, I would suggest putting one or more large washers in that gap (large enough to cover the whole bushing and then some) and see if that fixes the wobble. If not, then that was not the problem!

[Jackie]

Check out this forum iif you haven't already) and do a search for "death wobble". There are many, MANY comments/solutions for it: http://www.jeepforum.com/forum/f96/

[Hypoid]

First, a rubber bushing is bonded to the collar, a polyurethane bushing is not, and will have lateral movement if not captured. This has been touched upon by a few of the respondents to this thread. What are these bushings made of?

Second, what brand kit is this? Are there reviews on any JK specific forums?

The first and second questions may bring us to an Ahh-ha!!! moment.

Third, I've seen some baddass home built Johnny joint/flex joint arms that use the rebuildable joint at the body mount. I'll bet S&P Customs could weld some on your existing arms. :D

[Brody]

I would try what has has been suggested and that is to put larger fender style washers on the bolts to take up the gap. See what happens when you do and go from that. Poly bushings also make quite a bit of difference, being stiffer and less prone to wear.

[Aaron]

Here's what I think my plan of action is. I'd like to get new adjustable control arms but the funds won't allow it right now. I checked my caster and it is roughly at 7 degrees which is at the high end of factory spec. Everything I've read says that with larger tires, the caster is better at a lower 3 or 4 degrees. The lower the caster, the less chance of wobble. Since my stock control arms are shorter than my new ones, I'm going to put the old ones back on and see what happens.

I am going to remove the track bar this weekend to make sure the bracket and or the mounting holes are all still good. I'm going to rotate the tires again.

Lastly, I know its a mask, but since my wobble is relatively minor (slow speeds, not a death trap) I think I'm going to find a stiffer steering stableizer to help out as well.

[Aaron]

First, a rubber bushing is bonded to the collar, a polyurethane bushing is not, and will have lateral movement if not captured. This has been touched upon by a few of the respondents to this thread. What are these bushings made of?

Second, what brand kit is this? Are there reviews on any JK specific forums?

The first and second questions may bring us to an Ahh-ha!!! moment.

Third, I've seen some baddass home built Johnny joint/flex joint arms that use the rebuildable joint at the body mount. I'll bet S&P Customs could weld some on your existing arms. :D

Hey Mike. It's a Rough Country 3.5 lift and the CAs have rubber bushings. My guess is that the rubber bushing on that particular end of the CA has become unbonded since there are "clean" parts where the bushing could come in contact with the mount on the frame. The question is, could lateral motion on the CA cause this? Assuming the track bar is sound (and I think it is), it controls lateral motion.

And yeah, if Pete and Sean can do me up some good CAs, I'm willing...

[Aaron]

Check out this forum iif you haven't already) and do a search for "death wobble". There are many, MANY comments/solutions for it: http://www.jeepforum.com/forum/f96/

Yeap. I've been looking at all the writups on JK forums, jeep forums, etc and slowing getting through the list. I'm going to be taking the track bar off this weekend to make sure holes haven't been ovaled etc...

[Aaron]

I'm also going to be checking the ball joints on the passenger side as well. I've noticed that I can sometimes create the wobble just by making a sharp left turn. I'll rotate that tire out as well and see what that accomplishes.

[NCB]

Have you tried torquing all of the hardware to spec? A stiffer steering stabilizer will only be a bandaid.

[Aaron]

Have you tried torquing all of the hardware to spec? A stiffer steering stabilizer will only be a bandaid.

I've torqued and re-torqued and to no avail at this point.

[scout man]

those tires are brand new right? I cant imaging those are causing your problem unless they are REALLY out of balance. Im still sticking to the easy test first - just throw some washers in there and see what it does!

[Brock]

Have you wheeled it lately? My stock steering bent just enough where it didn't look bent but had wobble on the highway.

[Hypoid]

My guess is that the rubber bushing on that particular end of the CA has become unbonded since there are "clean" parts where the bushing could come in contact with the mount on the frame.
If the rubber can slide back and forth across the steel collar, that bushing has to go! Check it with a pry bar.

Also, check your tie rod ends: Have someone turn the wheel side to side while you look for play in each joint.

[SCRubicon]

How much longer are the CA's (over stock) you got w/ the lift. I used the factory arms on my Rubi 4 inch lift and never had death wobble. Only wobble I had was in about the low 40 mph range due to an improperly balanced tire. The jags where I picked up the lift and tires said I needed a beefier stabilizer. Sure... Masked it a little but it didn't go away. Re torqued everything. Couldn't figure it out. Called my old man and he suggested rotating the tires - front to back. Sounded to him like a boogered up balance job since the tires were radials. Worked. And, could have saved $50 bucks not buying another stabilizer...

[Aaron]

How much longer are the CA's (over stock) you got w/ the lift. I used the factory arms on my Rubi 4 inch lift and never had death wobble. Only wobble I had was in about the low 40 mph range due to an improperly balanced tire. The jags where I picked up the lift and tires said I needed a beefier stabilizer. Sure... Masked it a little but it didn't go away. Re torqued everything. Couldn't figure it out. Called my old man and he suggested rotating the tires - front to back. Sounded to him like a boogered up balance job since the tires were radials. Worked. And, could have saved $50 bucks not buying another stabilizer...

Check out the picture in post 4. That is the difference in length. I'm going to go through the front end with a fine tooth comb this weekend. I'll rotate the tires again. Stock control arms will probably go back on. I wand to check the ball joints in the front. I'll take the track bar off and check its mounts. I have a track bar bracket in the front (rather than an adjustable track bar) so I'll take that off and put it on again making sure all is tight.

Steve, are you running the stock track bar, relocation bracket or adjustable track bar?

[WINKY]

did you double check your lugnuts by chance?

[sunk]

Seems like you need different bushings, or washers...

Here is a link to get some more ideas: http://www.jpmagazine.com/techarticles/154_0906_fixing_jeep_death_wobbles/index.html

[Aaron]

I may have this thing licked. There aren't really any bad roads near me so I'll need to head downtown to test. Here's what I did.

1. Changed back the stock control arms which gets rid of the questionable bushings and dialed back the caster some. IT was at 7ish degrees before. I'll have to get back to you on what it is now but I bet its closer to 3. The bushings on the passenger side control arms are definitely suspect. (see pics)

2. Rotated the passenger side tires front to back. When I did this, I also took off the little throw away retainers (2) for the rotor that come from the factory. I don't know if that could have thrown my wheel off balance but it couldn't have helped.

Note: the pictures are both from the passenger side control arm but each picture represents a different end (i.e. different bushing). The other control arm did not have this cracking in the bushing.

[Hypoid]

Yup, that's all it takes. I'm surprised handling was not worse.

How old were these?

[Aaron]

Yup, that's all it takes. I'm surprised handling was not worse.

How old were these?

2 months

[Hypoid]

Ouch! You might look into poly bushings if they don't warranty those.

[Brad]

Are these preload links? Audi has several you have to preload the suspension prior to tightening the bolt.

[SCRubicon]

Steve, are you running the stock track bar, relocation bracket or adjustable track bar?

I'm all back to stock (mostly) now. All that's left are a couple of skid plates, winch/bumper, HD diff covers and the C.B. radio.

From experience, relocation brackets on JK's are bad news. Get adjustable track bars as soon as possible. When I bought my Superlift it came with a front adjustable track bar and a relocation bracket for the rear. After a few trips out I noticed the factory mount on the rear axle housing was starting to bend. In 2007 Jeep had a problem with them shearing off even without a lift and relocation bracket. Some companies out there make beefed up weld+bolt on relocation brackets, but I'd still steer clear. The extra $$$ spent on adjustable bars is money well spent IMO. I grabbed a rear adjustable track bar from Teraflex. I think it was around $130 at that time.

[Aaron]

Are these preload links? Audi has several you have to preload the suspension prior to tightening the bolt.

I don't know what preloaded links are, but the instructions forbid kit and others state to keep the bolts loose for all CAs tll the jeep is off jacks. That's what I did.

[Aaron]

Sent an email off to RC with pictures, etc. I let them know that I wasn't interested in replacing the control arms in the kit given I didn't feel the design was a good one but was interested in any ideas they had to make it right...

I'll let you guys know how it goes.

[Brad]

Preload means you have to load the suspension before tightening the bolts. Sounds like that is what the instructions stated.
Problem is you do not know how much preload it takes. IE when the vehicle is lowered onto the ground and you tighten
the bolts down did you roll the vehicle back and forth to get the geometry of the suspension to level? Any angle can
compromise the tension on the rubber bushing causing a tear in the rubber. Kind of like what you see there. Either way
if they did not specify a professional install the kit (in other words they said it was ok for a DIYer to install it) then you
have every right to return it as faulty product. ;)

[Aaron]

Oh I rocked it!

[Brad]

:thumb: