I've been reading and listening to opinions about ways to solve driveline vibrations. Some things I've tried have changed the mph when the vibration occurs but none have solved the minor but noticeable vibration.

So before spending more money, I'm hoping some XJ gurus with calibrated eyeballs can look at the pictures below and tell if the shims put the piņon angle too close to straight with the driveshaft?

Here's the history on this particular problem with my 99 XJ:

130K and the springs were sagging, rear at 16" from axle to flare / front at 17"

A local shop added new coils in the front and reworked the rear springs so that now the bottom of the front and rear flares measure 19" from the center of the axle.

After the work, it drove and handled great but had a distinct vibration from 20 mph to 40. Before the lift there was minor vibration above 70mph but after it was a lot worse.

Put in 2 degree shims. No noticeable difference

Changed both rear u-joints, this made a difference but didn't completely fix it

Put in a temporary 3/4' T-Case drop. At first I thought it helped but when I took it back out I didn't notice the vibration getting worse.

Any hope that a SYE for this NP242 T-Case equipped XJ can be avoided? All help is much appreciated!!

 

Pinion angle looks too high. Normally one doesn't use degree shims unless a Double Cardan drive shaft is used.

watch this...

 

I doubt it can be remedied with a stock driveshaft. I reworked my saggy stock springs on my 99 and had to do a 1" tcase drop to get the vibes to go away & its not really lifted. 1" max....


Just do a hack and tap with a used front shaft from an auto, it can be done in an afternoon & for 150bucks. All the messing around isn't worth it.

 

I thought the whole point of having an XJ is to have something to mess around with? But I do appreciate the advice!

 

I'd rather not drive with a vibrating driveshaft & work on other stuff.