Troubleshooting vibration

[Shive]

After installing the 2.5" OME/Bilstein lift (with alignment), I noticed a bad vibration between 35-50 mph.

I've seen a few threads about the vibration between 35-50 mph generally being due to worn u-joints.

I just replaced with Spicer HD non-greasable (5-1310X) u-joints. Of course I marked the driveshaft components to ensure proper reinstall and torqued to spec (no threadlocker with the flange bolts per @tommudd ). I still have the vibration, although maybe just a little less intense.

I'm thinking front driveshaft rear CV would be my next focus, but wanted to get thoughts on anything else that could cause the vibration before I pull that and rebuild it.

 

[lfhoward]

Front driveshaft rear CV is a common failure point (rubber boot breaks, losing grease and allowing in grit) but the angle of the front driveshaft doesn’t change at all when you install a lift. You could pull the front driveshaft entirely and see if the vibration disappears. If the rear cv on the front driveshaft is toast, Driveshaftparts.com has a quality replacement cv for under $40.

 

[Luke]

I chased those vibes for months after lifting… some KJs have it worse than others. I replaced just about everything from the tri link all the way to the front. Never went away.

 

[Shive]

Front driveshaft rear CV is a common failure point (rubber boot breaks, losing grease and allowing in grit) but the angle of the front driveshaft doesn’t change at all when you install a lift. You could pull the front driveshaft entirely and see if the vibration disappears. If the rear cv on the front driveshaft is toast, Driveshaftparts.com has a quality replacement cv for under $40.

I've had the rebuild kit sitting on a shelf in my garage for over a year...lol. I had originally bought it after we got the KJ, read up on common issues, and saw that the front driveshaft rear CV was a usual failure point. Never seemed like it was bad, so I hadn't pulled it, but guess its time to actually pull and rebuild it.

 

[Shive]

I chased those vibes for months after lifting… some KJs have it worse than others. I replaced just about everything from the tri link all the way to the front. Never went away.

Not encouraging but at least I'm not alone.

 

[Luke]

Hey maybe yours is the not worse kind

Didn’t mean to discourage… like you I was able to affect the level of the growl with parts but just not able to completely solve it.
In the end it was “quiet enough” and we just agreed that if I wanted to keep my lift, I would have to put up with her complaining about it

 

[Shive]

Hey maybe yours is the not worse kind

Didn’t mean to discourage… like you I was able to affect the level of the growl with parts but just not able to completely solve it.
In the end it was “quiet enough” and we just agreed that if I wanted to keep my lift, I would have to put up with her complaining about it

Looks like I do have the same luck...lol. I took the front driveshaft out to rebuild the rearward cv and just drove it before I reinstalled. Still have the vibration.... Like you said a bit less growl, but still there. The rearward CV had some play and clearly was bad, so I was hopeful that the rebuild would fix it, but no dice.

 

[Shive]

While rebuilding the front driveshaft CV, the bearing seemed really tight, to where it was hard to get enough movement to get grease packed into it, but I figured once it was packed with grease and on the splines it would have the needed movement. Nope. Couldn't get any articulation at the CV at all, so I couldn't install it. There was already some obvious issues with the machining with the bearing getting stuck partway down the splines and it being so insanely hard to get any movement at all in the bearing initially, so I'm going to call drivelineparts today to see what they can do. If I can't get any movement with it cold, I'm assuming it'll be even worse once its in use and warms up, if even a little bit.

 

[Shive]

Called Driveshaftparts and he asked if I took the bearing apart or if it was apart at all when I got it. Indeed one of the ball bearings was out bouncing around the box when I opened it. I cleaned it and put it back in, but he said the alignment of the inner piece could have been off a little bit, which would cause it to lock up like it is. Time to take it back apart and see if we can get some movement.