Vibes after SYE

I’ve had vibes after I installed my SYE from AA on. I have had my drive shaft returned and balanced 3 times and if put a used front drive in the rear the vibes are there just not as bad. My pinion angle is around 3 deg.

I’m thinking that it’s coming from tranfer case to transmission. Has any one had this problem???

Specs.
98, 6.5 lift, auto, 231, 8.25

Thanks,
Kevin

First - get an angle finder and check it seven times to make sure your angles are set correctly.
Then see if your tires are balanced. I was vibe free till I rotated my tires... then I had to get them balanced again.
After that... did you have a Tcase drop before the SYE? Possible that your motor mounts were tweaked by dropping tcase and that there is now some play, creating vibes.

I’ve have an angle finder and checked numerous times to the point that I know that it’s not coming from the pinion angle. Not tires I have new ones. Tried Tcase drop did not help replaced motor mounts.
I can hear a slight thumping noise from a dead start and get a humming noise/ feel when I’m on the throttle and at worse at top speed about 70.

Well, at this point all I can guess is that "new tires" doesn't necessarily mean "balanced" tires. Sorry can't be more help.

Had the vibes with old tires and new.
Thanks any way.
That’s why I’m posting hoping that some one also had the same problem and has an answer.

I had a similar problem. Sent the drive shaft back to the place I purchased it from 3 times including a completely new shaft. Vibes still there. I lived with them for two years then had some down time on my Xj and sent the shafts to a different shop to be balanced. Problem solved. You may want to find someone local to check the balance on the shafts.