Driveline Vibration

[jholley]

My truck has a resonant vibration at highway speeds thats driving me crazy. I've searched this topic and read all the responses to others having this problem and still have a question. Has anybody here had to adjust pinion angle after lowering 3.5/5? My truck is a 72 longbed with a two piece driveshaft. I took the driveshaft to a driveline shop and had all the u-joints changed as well as the carrier bearing, then had it balanced. The transmission has been rebuilt and so has the rear end. I know to always go back to the last thing worked on before the problem started to troubleshoot which would be the rear end. I found some slop in the pinion bearing that my mechanic is going to fix next week but I'm still wondering about pinion angle.