driveshaft angles

str12-340 said

I have a cyclic vibration in a totally new drivetrain that I would usually associate with a problem in driveshaft angles. If I put the car on a lift and adjust things so that the transmission pan rail is flat, the angle of the 8 3/4 rear chunk as measured at the mounting pads for the pinion snubber is 3 degrees down. This is NOT a RACE CAR. The priority is to have a smooth ride on the highway. Is 3 degrees enough to cause this? Should I be striving for them both to be 0 degrees (parallel).

If so, can anybody suggest a source for angle shims for the spring pads?

Click to expand...

Here's a good video. I have been told by people I trust that pinion shaft angle 2-3 degrees down (from the engine/trans shaft center line) is good for a street mopar, and 4 degrees down is good for a street/strip mopar that has the front spring section stiffened, like with clamped front leafs or caltracs. I get confused when measuring the drive shaft angles and then doing all adding and subtracting, so I got a magnetic digital angle guage from Harbor Freight. Zero the guage at the transmission output and then it will read the degrees difference at the pinion yoke. I disconnected the drive shaft to get access. In the horizontal direction, have you measured the thrust angle?

Lots of places sell axle angle shims, including Mancini, Calvert, Holley, and Summit, and as mentioned previously Dr. Diff. In fact, Cass would be the very first person I would contact if I had a vibration problem like yours. [email protected]