Compound ujoint angle vibration?

Had the same problem,,yoke was worn on front differential not keeping u-joints exactly centered in yoke,,new u-joints would not last more than 3 months,,,had a chatter vibration at 55,,replaced yoke,no more vibration

 

On mine,the little tabs that centered the u-joint caps were worn allowing the u-joint caps to sread out even though the half circle straps were tight,,finally on the 3rd set of u-joints our shop guy noticed the worn tabs on the yoke,,once the yoke was changed the problem went away,,of course the new seal started leaking 2 days later,,after fixing the defective seal, it has been good since

 

Did you ever figure out the issue ? Going through the same issue

 

Find a GOOD driveline shop. Somebody old school. Old school cutting lathe, and someone who actually knows how to reduce yoke runout without throwing weights at the drive shaft to “balance”. Weights on a drive shaft is proof of someone not knowing how to reduce yoke end run out.