TJ shakes above 40 mph

[Sakenney1980]

When I get my tj above 40mph I get a shake in the front end and the wheel alignment goes a little bit out. I replaced all the tie rods and track bar and put 32 inch tires on it replaced shocks that match the 4 in lift kit. Please help this is one of the last few things to fix on this restoration. I’m willing to try anything

 

[Jerry Bransford]

Describe the shake please. Like the steering wheel shakes at a certain speed?

Or the whole Jeep shakes VIOLENTLY like the devil has it in his hand making your life pass before your eyes and you are ready to crap in your pants? If that's the case that's called Death Wobble which is fixable.

Speed sensitive vibrations and shakes are usually caused by a bad or imperfectly balanced front tire.

 

[Sakenney1980]

I’ve never driven a death wobble Jeep so I’m not sure about that but it makes me not want to drive any faster than 40 mph and at that speed it feels like the worst alignment ever.

 

[Jerry Bransford]

I’ve never driven a death wobble Jeep so I’m not sure about that but it makes me not want to drive any faster than 40 mph and at that speed it feels like the worst alignment ever.

As in the steering wheel is twitching back & forth? If so I'd strongly suspect nothing more than an imperfect tire balance or a bad tire. The bigger the tire the less likely a tire shop will take the time to balance it perfectly well enough to not have speed-sensitive vibration.

I had to have my 35" tires balanced 3X in one day once. It was on the third try they finally got the hint they needed to spend the time required to get them balanced perfectly or I'd be back a 4th time.

 

[Sakenney1980]

As in the steering wheel is twitching back & forth? If so I'd strongly suspect nothing more than an imperfect tire balance or a bad tire. The bigger the tire the less likely a tire shop will take the time to balance it perfectly well enough to not have speed-sensitive vibration.

I had to have my 35" tires balanced 3X in one day once. It was on the third try they finally got the hint they needed to spend the time required to get them balanced perfectly or I'd be back a 4th time.

 

[Sakenney1980]

Did you pay them for the balancing?
I haven’t done a keep since I was in high school and bought this one for $500 the only thing that we’re good was the engine transmission and 4 wheel drive

 

[Jerry Bransford]

Did you pay them for the balancing?

I paid them for one balance job, the extra two to get it right were on their dime.

 

[Sakenney1980]

I paid them for one balance job, the extra two to get it right were on their dime.

What are the characteristics of the death wobble? And what is the fix?
Thanks for your help

 

[D M]

Doesnt hurt to check if you have a dropped pitman arm too, and x2 to balancing. Show us a picture of your pitman arm. This will help you with identification if you dont know what youre looking at

I had a dropped pitman arm when I bought my jeep and it gave me all kinds of trouble when driving at higher speeds, I swapped in a stock one and my problems went away

 

[Sakenney1980]

Doesnt hurt to check if you have a dropped pitman arm too, and x2 to balancing. Show us a picture of your pitman arm. This will help you with identification if you dont know what youre looking atView attachment 218452
I had a dropped pitman arm when I bought my jeep and it gave me all kinds of trouble when driving at higher speeds, I swapped in a stock one and my problems went away

 

[Sakenney1980]

I hope I don’t get rid of the old pitman arm

 

[Jerry Bransford]

What are the characteristics of the death wobble? And what is the fix?
Thanks for your help

Its characteristics were described in my first post above. Its cure is most commonly getting the tires perfectly balanced. My worst case of Death Wobble resulted from one of my front tires having lost its balancing weight. Replacing it fixed the DW. It can also be caused by a combination of an imperfect tire balance (or bad tire) and something that is not mounted tightly enough, like the track bar.

 

[D M]

I hope I don’t get rid of the old pitman arm

Its a rather simple fix using a pitman arm puller and is a known issue if its dropped. Can you send us a picture of your pitman arm

 

[Sakenney1980]

Its a rather simple fix using a pitman arm puller and is a known issue if its dropped. Can you send us a picture of your pitman arm

I changed the pitman arm to a drop one

 

[SPECWAR]

I chased a vibration that occurred around 45mph on mine for a while. Finally found the front drive shaft was bent so I replaced it. It was .065 out.

 

[Sakenney1980]

I chased a vibration that occurred around 45mph on mine for a while. Finally found the front drive shaft was bent so I replaced it. It was .065 out.

 

[Sakenney1980]

It isn’t a vibration it shakes

 

[SPECWAR]

Vibration = quickly moves back and forth.

 

[D M]

I changed the pitman arm to a drop one

View attachment 218461

I would bet good $$$ that is your problem. It throws your steering geometry out of whack. For the reason you put yours in I do not know, whoever told you should be running that is highly misinformed, whether it was a person or it came with a kit. For 99.99% us TJ owners, you shouldn't ever be running a dropped pitman arm unless you're doing a serious custom application Put a stock one back in and I guarantee your problem will be solved.

 

[Sakenney1980]

I would bet good $$$ that is your problem. It throws your steering geometry out of whack. For the reason you put yours in I do not know, whoever told you should be running that is highly misinformed, whether it was a person or it came with a kit. For 99.99% us TJ owners, you shouldn't ever be running a dropped pitman arm unless you're doing a serious custom application Put a stock one back in and I guarantee your problem will be solved.

Thanks I just ordered it after looking for the old one. Stupid me kept old track arm and all control arms with bad bushings but not the perfectly logos pitman arm