Driveline Vibration with 37’s

[Walldo]

Did you try to run without the front drive shaft and see if the vibration is still there, or just with the rear removed ? Did it vibrate with the stock tires and wheels after the lift? You say you tried your buddy's 37's and it was worse. Do you still have the stock set to try? Pinion angle might be the problem, or it might not be. Might be a front or rear output bearing on your T/C or front drive shaft out of balance. The thing is you did not increase your drive shaft speed, which makes most vibrations from the drive train more noticeable, you slowed it down with the larger tires and stock gears. The only thing you changed was the suspension, tire and wheels. Like has been said, not enough lift to cause problems and it didn't vibrate before the lift and tires. It might just be the tires. I have had nothing but bad luck with the last 3 sets of BFG tires I have owned. Even after having them Road Forced balanced, they were to far out of round to ride smooth. I will never purchase them again. Just thinking out loud, not sure it helps.

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[Alabama Mud Machine]

this has been tried and failed to improve vibration unfortunately

Short of having a warped tail shaft in your transfer case, or a bent pinion... I think you might have a bent flange on the T-case or pinion where the drive shafts bolt to on either end. It's worth checking it out to see. At this point, what do you have to lose?

 

[Shootist]

So many things have been tried. The one thing that seemed to stop the vibration was removing the front driveshaft if I read that correctly. Now my thoughts on this is that when they did the lift install they somehow jacked up the pinion angle. It seems to make sense in my head anyway because you haven’t done much with the vehicle I don’t think to damage anything have you? The trouble was not there before the lift was installed correct? It is not that hard to check your pinion angle if the front and back don’t match then you know something was done screwy in the install though for the life of me I can’t figure out what that could have been. The angle of the driveshaft at the front diff pinion should be identical (or very close) to the angle of the driveshaft at the TC. Here is a guide to help you.

https://www.quickperformance.com/Pinion-Angle-Measurement_ep_45.html

 

[Gem1n1]

So many things have been tried. The one thing that seemed to stop the vibration was removing the front driveshaft if I read that correctly. Now my thoughts on this is that when they did the lift install they somehow jacked up the pinion angle. It seems to make sense in my head anyway because you haven’t done much with the vehicle I don’t think to damage anything have you? The trouble was not there before the lift was installed correct? It is not that hard to check your pinion angle if the front and back don’t match then you know something was done screwy in the install though for the life of me I can’t figure out what that could have been. The angle of the driveshaft at the front diff pinion should be identical (or very close) to the angle of the driveshaft at the TC. Here is a guide to help you.

https://www.quickperformance.com/Pinion-Angle-Measurement_ep_45.html

It was the rear shaft i took out and didn't feel the vibration.

Haven't done anything to damage anything.

I think i'm going to take out the rear shaft and confirm again that it doesn't vibrate. I've tried so many things to this point it's all blending together and i feel i need to start over.

I'll clock some more miles and higher speeds with it out. Curious how fast you can go in 4H?

From there i'll take the front shaft out and repeat.

This should at least narrow it down to the front or rear being the issue.

 

[Alabama Mud Machine]

It was the rear shaft i took out and didn't feel the vibration.

Haven't done anything to damage anything.

I think i'm going to take out the rear shaft and confirm again that it doesn't vibrate. I've tried so many things to this point it's all blending together and i feel i need to start over.

I'll clock some more miles and higher speeds with it out. Curious how fast you can go in 4H?

From there i'll take the front shaft out and repeat.

This should at least narrow it down to the front or rear being the issue.

I wouldn't hit the interstate, and I'd stay under 55...Personal opinion.

 

[Shootist]

Not sure where I was getting the front driveshaft from. I still say go get you a $10 magnetic protractor from harbor freight and check your pinion angle. I realize that normally a 2” lift would not require pinion angle to be modified but in my head things like rear axle brackets welded out of place by the factory. wrong control arms in the box for the lift kit? Mechanic didn’t swap out a component? A bent axle perhaps?

Does the vibration get worse as the speed increases?

 

[Renegade]

Y’all do know that the front driveshaft doesn’t turn when in 2wd, right? FAD...

 

[Gem1n1]

Y’all do know that the front driveshaft doesn’t turn when in 2wd, right? FAD...

Doesn’t the front driveshaft still turn its the transfer case that free wheels internally?

 

[Gem1n1]

Not sure where I was getting the front driveshaft from. I still say go get you a $10 magnetic protractor from harbor freight and check your pinion angle. I realize that normally a 2” lift would not require pinion angle to be modified but in my head things like rear axle brackets welded out of place by the factory. wrong control arms in the box for the lift kit? Mechanic didn’t swap out a component? A bent axle perhaps?

Does the vibration get worse as the speed increases?

Yes, you don’t feel anything until mid 50’s which is a low pitch wide vibration if you will.

It then becomes a more rapid higher pitch vibration from upper 60’s on up to as fast as you can drive

 

[Shootist]

Yes, you don’t feel anything until mid 50’s which is a low pitch wide vibration if you will.

It then becomes a more rapid higher pitch vibration from upper 60’s on up to as fast as you can drive

That sounds exactly like a bad pinion angle. no driveshaft = no issue which rules out any axle based or tire based issues. The only thing remaining is TC and Driveshaft.

 

[Renegade]

Doesn’t the front driveshaft still turn its the transfer case that free wheels internally?

No. JL and JT have a front axle disconnect. This saves minuscule amounts of fuel by not having as much of the driveline turning while driving.

 

[Gem1n1]

No. JL and JT have a front axle disconnect. This saves minuscule amounts of fuel by not having as much of the driveline turning while driving.

Wow. Seems like an extremely overly complicated solution to a problem that didn’t exist.

glad you pointed that out before i started pulling my front shaft out getting more frustrated when it didn’t make a difference.

 

[Factoid]

Reading through this thread and your troubleshooting experience, and assuming you have no steering issues (normal solid axle steering, properly performing steering box, steering returns to center, etc.) and the fact that it completely goes away when you remove the rear drive shaft, I’m thinking TC. Why it only started after your lift and 37s is a mystery unless there was some TC related incident you haven’t shared.

 

[Gem1n1]

Reading through this thread and your troubleshooting experience, and assuming you have no steering issues (normal solid axle steering, properly performing steering box, steering returns to center, etc.) and the fact that it completely goes away when you remove the rear drive shaft, I’m thinking TC. Why it only started after your lift and 37s is a mystery unless there was some TC related incident you haven’t shared.

no incident. Went off-road one time. Only contact with rocks was the tow hitch.

I’ll take the rear shaft out again and drive it. I didn’t take it pass 65mph last time i did. I’ll get it up in the 70’s to triple check the vibration isn’t there with the rear axle out.
If it isn’t, from what i have gathered this will drill the options down to 3.

rear pinion angle, t-case flange or axle flange. I’m on my second rear shaft so that would theoretically eliminate that as being the culprit.

 

[kelkolb]

The rear

no incident. Went off-road one time. Only contact with rocks was the tow hitch.

I’ll take the rear shaft out again and drive it. I didn’t take it pass 65mph last time i did. I’ll get it up in the 70’s to triple check the vibration isn’t there with the rear axle out.
If it isn’t, from what i have gathered this will still the options down to 3.

rear pinion angle, t-case flange or axle flange. I’m on my second rear shaft so that would theoretically eliminate that as being the culprit.

The rear pinon angle should be zero problem though, especially with the rear shaft at the axle being a CV. Only a problem if the joint is bad. T-case definitely sounds like the culprit.

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