Vibration Issues

Alrighty, so I had some vibration issues (I thought from my driveline angle) that I "solved" a week or so ago. I have a 73 CJ with a ~3 in lift, T18 and D20. I had put on a CV shaft on roughly a year ago or so when I threw my old shaft. My T-case went out so I rebuilt that and also replaced my rotten t-case mount. The added 1-2 in from the new mount (the old one was so rotten it had lowered the t-case) started some driveline vibrations. A couple of weeks ago I rewelded the perches so I had that magical 1-2* driveline angle. Now I have excessive vibration in gear, and it's more pronounced when accelerating. No vibration when out of gear and coasting at any speed. Everything's tight, no play in my rear shaft, and I can't find anything really out of whack. What are the possible causes (U-joints, motor mounts, etc.) so that I can run through the more likely causes? I was wondering if perhaps my cheap angle finder was off a little and I angled the shaft up too high possibly? It looked good to the eye, but I can't see real well due to mufflers from the duel exhaust. As always, thanks in advance!

 

What angles are you running now? That would be the starting point. U-joint as well as driveline.

 

So many things could cause it.
A motor mount bad, some part of the motor or trans against the frame or body on accerlation.
The angle of the shafts.
The pinion bearngs in the axle.
The transfer case bad rebuild, (although with a bad bearing inthe output shaft, you'd think you'd have an oil leak).
The drive shaft bent a tad.
the slip joint and back drive shaft "U" joint outta faze(sp?).
The slip joint B.A.D.
Take it one thing at a time and leave nothing to chance!
Joe
I hate that feeling, SOMETHING is wrong anf you can't figure out WHAT it is. It all looks good but......

 

@nickmil-my u-joint angle is 1-2 degrees and do you mean the angle read on my driveline shaft? I think I need to go buy a new angle finder first thing. I have a suspicion that my cheap one is off.

 

Were is the angle on your driveshaft?


The pinion should point down a few degrees as the pinion rotates slightly upward under power.