I haven't read your entire thread, but this post caught my eye. I also installed a 4 inch lift (BJ's) and am experiencing vibes at about 56+ mph. I removed the front DS and put the jeep in E-drive and put about 40 miles on it. Still had vibes. Tires balanced and rotated, no change. Pinion angles all seem to be good as best as I can tell. New u joints on both driveshafts and a new centering ball on the front shaft. My tires are 33x12.5-15. If you find an answer to the vibes, I'd love to hear it.1979bettywhite wrote:So after driving around for a few days with the lift, I am experiencing some vibration starting around 45 mph and on up. It feels like it is mainly coming from the rear. I have measured the transmission output and rear diff angles and they are one degree different. So I don't think the vibration is the result of that. And all I have read about on 4" lifts here it does not seem that any have had to use shims to adjust pinion angles in our FSJs.
I have had a shop I trust balance the tires. They do an on car balancing, and are highly respected in my area of town. Many people bring their track cars here for alignments and balancing.
The wheels I have are Centerline Convo Pros and they are lug centric. Before the lift, I had 0 issued with vibration etc and that was on 31x10.50 big all terrains.
So from what I have read, maybe the first place to start is by eliminating variables. I read that you can remove the front DS and put it into emergency drive and drive around. That would eliminate the front DS possibly.
I have also read that swapping out the u joints is a wise decision when doing a lift. I am probably on the stock u joints so this is probably wise for me to do regardless. Are there any that you guys recommend? I plan to go back with a greaseable u joint at least.
Any other thoughts or suggestions?
Tim, did you get an alignment?Curly wrote:I haven't read your entire thread, but this post caught my eye. I also installed a 4 inch lift (BJ's) and am experiencing vibes at about 56+ mph. I removed the front DS and put the jeep in E-drive and put about 40 miles on it. Still had vibes. Tires balanced and rotated, no change. Pinion angles all seem to be good as best as I can tell. New u joints on both driveshafts and a new centering ball on the front shaft. My tires are 33x12.5-15. If you find an answer to the vibes, I'd love to hear it.1979bettywhite wrote:So after driving around for a few days with the lift, I am experiencing some vibration starting around 45 mph and on up. It feels like it is mainly coming from the rear. I have measured the transmission output and rear diff angles and they are one degree different. So I don't think the vibration is the result of that. And all I have read about on 4" lifts here it does not seem that any have had to use shims to adjust pinion angles in our FSJs.
I have had a shop I trust balance the tires. They do an on car balancing, and are highly respected in my area of town. Many people bring their track cars here for alignments and balancing.
The wheels I have are Centerline Convo Pros and they are lug centric. Before the lift, I had 0 issued with vibration etc and that was on 31x10.50 big all terrains.
So from what I have read, maybe the first place to start is by eliminating variables. I read that you can remove the front DS and put it into emergency drive and drive around. That would eliminate the front DS possibly.
I have also read that swapping out the u joints is a wise decision when doing a lift. I am probably on the stock u joints so this is probably wise for me to do regardless. Are there any that you guys recommend? I plan to go back with a greaseable u joint at least.
Any other thoughts or suggestions?
Yes. Tightened the shackle bolts down to 30 ft lbs and the fixed mount locations at 60 ft lbs. Using stop nuts all around so not to worried about those backing off. U bolts are at 65 ft lbs. Have some solid spicer 1310s on the way. Will throw those in the rear ds first.az chip wrote:You said you were going to leave some bolts loose for the springs to settle in. Did you ever tighten those? And yes, change out the U-joints. DPA? Did you get alignment checked after lift install?
[/quote]az chip wrote:Curly wrote: Tim, did you get an alignment?
I had scream steering above 30 mph. Where I would scream any time above that speed. Not fun. Alignment helped. DPA helped more. I might need to replace bearings.1979bettywhite wrote:AZ, I did get the alignment done while I was at the shop. They actually did not even touch the alignment, said everything numbers wise looked really good. Asked them about the angle of the draglink and he said it really wasn't all that bad. And if I wasn't experiencing any pronounced issues with driving and steering, he would probably leave it alone and not do the drop pitman arm.
We will see how things are once I get the new u joints in.
I did measure. Not much different. Less than 1 degree.1979bettywhite wrote:Is that driveshaft pinion angle? Did you measure yours after the lift? I think I am only one degree different on mine.
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Vibration controlaz chip wrote:My parasitic drain is married to me.
What is the reason for rag joint steering?