My 03 diesel with HD auto tranny has started to develop a loud bang/knock when going between forward and reverse and occasionally when locking up in overdrive.

I'm thinking it's not the pinion gears because there is no whine associated with usual pinion gear issues.

I'm sure it's caused by the really sharp lockup from the HD tranny.

Any ideas on what to it could be. Someone suggested to drop the drive shaft and tighten the pinion gear nut?

Any help would be appreciated.

Thanks

Ron W.

 

Check your Universal joints.