I have a slight vibration in my rear end as im accelerating past 75 mph?
No vibration 75 mph down. Its not the tires as i just got them rotated and balanced. Its not the transfer case or drive shaft as i got both new last year (2014). As soon i let off the gas the vibration diminishes, so if im cruising at 80 mph, the vibration is noticeable and once i let off the pedal.... the vibration is gone while decelerating even 75 mph. Could this be a bad pinion?
Check carrier bearing / Wheel bearing
Put the back tires on the front and the fronts on the back and see if that helps you find it. Just because you got the wheels balanced doesn't always mean the job was done correctly. You also could have an out of round tire.
Bought her some new shoes last week 1/20/15 from walmart. Dynapro ATM. the vibration was even there with her old tires on and i thought hopefully it was just an out of balanced tire but sadly not the case.
This is one of those problems that may be hard to find. Could be driveshaft out of balance (not a common issue), carrier bearing if it has one, out of balance brake rotor (not a common problem), bent wheel (common), wheel installed where a brake rotor retainer washer interferes with the wheel being flush against the hub (probably more common than we think) and possibly a wheel bearing. Have you tried taking it out of overdrive at that speed to eliminate and engine vibration?
Im wondering if its not the pinion shaft due to my old driveshaft having a bend in it and destroying my transfer case....
Could be, also could be the pinion yoke.
that would be awesome if that was all.
Ill check back in as soon as i get into the shop and get a good look at everything.
Good luck with it.
Looking for a Used Sierra 2500HD in your area?
CarGurus has 15,315 nationwide Sierra 2500HD listings starting at $1,900.
Search GMC Sierra 2500HD Questions
GMC Sierra 2500HD Experts