Pinion angle

[1941Rick]

I have just updated the driveshaft on the 41 P12...took out the original and build a modern u-joint shaft....do I have to change the pinion angle....

Reason for asking is the vibration I am getting around 55 mph.....for some reason I feel the diff pinion is in line with the output of the trany....Conventional u-joint must have an angle......

Can anyone enlighten me.....

[Plymouthy Adams]

if your engine is setting in stock positon and so is the rear gear, unless your rear springs are bent inverted..the driveshaft angle and should not have been disturbed no need any addition correction as there has been no change made..correct facbrication of the driveshaft to be in phase to itself front and rear and balanced should not result in any vibration..however do regard all parts of the system to include motor mounts rear eng.tan mounting and forward silencing bolocks and rear shackle bushings..it all come together for a proper fit and afunction..if under applied torque the rear is allowed to shift about due to loose or worn parts..you could induce an out of phase condition.

[Alshere59]

Just a thought. If the wheels are true and have no run out in them check the balance. If all that is good look at your pinion bearing and rear end lube level. Mine had a vibration I couldn't find either. That is until I took it for a test drive then put it on ramps. The pinion seal yoke for the rear end was warm very. It never made a peep not one noise. I did have a leak but it didn't seem bad just something that needed to be done. I guess it had leaked for a bit before I got the car.

This assumes you don't feel the vibration through the steering wheel which is a whole different ball game.

Edited May 22, 2011 by Alshere59