JoyMarie

So....I read through the FAQ sticky and I'm still unsure of what I should do. I had the 2.5 inch RC Series II lift with out shocks installed on my 2013 JKU this weekend. I haven't driven it a lot since then but I was driving it home from the gym tonight and hit a nice bump while I was running about 45-50 mph and it started shaking uncontrollably. I had to slow to almost a stop to get it back to normal.

I have not had it aligned since the lift. Is that something I need to have done or do you think it is something else causing it?

Any help is greatly appreciated!



This is the lift I had installed:

Mr.T

Alignment is a very low probability. High probability is that the trackbar is loose or under-torqued and is moving at one/both ends in the mount. It could be a lot of things, but it comes down to too much free play with the forces involved in holding the wheels in the steering axis.

Death wobble can damage other components and make the problem worse, so don't drive it more than you have to. Since you had the lift installed, I'm going to presume fixing this is out of your lane and suggest taking it back to the installer.

JoyMarie

Thanks! I can check the track bar myself but if it's too much more in depth I will take it back to the guy who installed it. He's a friend so shouldn't be a problem.

Mr.T

In case you need it, the trackbar bolt torque spec is 125 ft-lbs. On a safety side note, if you have someone move the steering wheel back and forth to check for movement/play be careful of getting in a pinch point, or over-heating the power steering fluid (which can blow a power steering hose and cause injury).

Hopefully it's something simple and easy.

nthinuf

Yep, trackbar is the most likely cause, but could be a number of things. If you have some free time, go up to the JK Write-Ups section and open the Diagnosing Deathwobble/Shimmy thread that is stuck right to the top.

And as noted, minimal driving is a good suggestion until the source is identified, since each time it happens more components could potentially be damaged and costs can go up accordingly.

Mark Doiron

Had a friend who had installed a lift and then drove it for a bit while trying to figure out what was causing DW. One of the things we found was that the holes for the trackbar bolts had ovaled out (this is part of the extended damage referred to above). It turned out he could stop the DW by overtorquing those bolts--up to about 165 ft-lbs, IIRC. That wasn't the fix--welding in 1/2" washers for his 9/16" bolts was. But, it indicates that even if properly torqued, you would still be wise to check out those bolt holes more closely. After the work was all done, he also found that his ball joints were bad. If you have OEM ball joints and, oh, maybe more than 30-40,000 miles, might also consider checking them out very closely. As you can imagine, there's a lot of force expended during DW incidents and those OEM BJs are easily worn out/damaged.

JoyMarie

Thanks for all the advice. I work for a small engine company so I am going to pull it in the shop today and check out everything mentioned. Would you recommend having it aligned also? Not to fix the DW but just in general after installing the lift? I read where it's a good idea.

resharp001

There's not much they can do in regards to aligning what you have. They can set toe and re-center the steering wheel for you. It's good to have the alignment specs anyhow though so you can see what your caster is, as you likely need some form of caster correction like control arm brackets. A lot of places will put a vehicle on the rack and do the readings, presenting them to you and then asking you if you want them to do the suggested changes, which again are going to be very minimal on that. If you say no, they should give you the print out and send you on your way for little or no cost. You're toe spec shouldn't be out of whack since you didn't touch the tie rod.

And I agree with all the above. Highly likely you have a loose TB bolt since the lift was just installed. If you don't have one, a 50-250ft lbs torque wrench is helpful to have. Our jeeps are intolerant to under torqued bolts. This is a situation where "tight" is not good enough. Hopefully you didn't wobble so bad you blew factory ball joints out.

Mr.T

Here's another thought on the trackbar and how the bushings in the ends are retained in the brackets (same for control arms):

It's the clamping force of the faces of the steel inner bushing that the bolt goes through, against the inner faces of the bracket that holds it from moving. These faces should be clean, free of nicks and any deformation/wear caused by the steel inner bushing moving in the bracket. A minute with a flat file will usually do the trick. It's much more important that the faces mate well then the bolt having some radial play in the hole. The radial play of the bolt hole is like a backup restraint after the clamping force against the faces fails to hold. If the faces don't mate correctly when tightened, the bushing will move under load, wearing and/or deforming metal, and making it progressively looser in a vicious cycle.

dan3jeeps

I thought I had everything covered. Trackbar, tie rod, drag link, steering stabilizer, mounting bolts, tire imbalance, all of it...

I still occasionally got the dreaded wobble. Not often, but I still did at totally random occasions. No damn rhyme or reason.

Then I broke the front D30 axle housing and upgraded to a TeraFlex D44 and all the wobble disappeared. no wobble for 2.5 years now.