Pinion angle

So the drum brakes are installed and the new e-brake cables adjusted to the relocated Lokar handle, locks up the rears in two clicks.

Next is to measure and modify the original driveshaft as the WCT5 is about two inches longer than the original Muncie. During all of this I need to check and correct if necessary the pinion angle of the rear. This is a MX with a four link so the upper control arms are adjustable.

1. Any advice on shortening the original driveshaft vs having a new one made?

2. Are we still looking at a 3 degree pinion angle (Currie Enterprises suggests 2 degrees regardless of the kind of rear suspension).

3. Anyone ever try to adjust the four link, how did that go??

4. The upper arms tend to eat themselves up due to binding issues common to 4 link suspensions. One of my rod end bearings was bad when I took delivery of her. There are many aftermarket upper/lower arm products out there. If I have to pull it all apart now would be the time to substitute aftermarket parts. Anyone experiment with this...recommendations??

Paul

You should be able to shorten your old driveshaft as long as it is straight. Some factory shafts are made of large diameter tubing and swaged down on the ends to fit the yokes. These don't allow much shortening, but I'm guessing yours is straight tubing.

The pinion angle should compliment the engine/trans angle. If the engine tilts down 3*, then the pinion should tilt up 3*. However, the rule of thumb recommendation is to point the pinion down 2* from the above numbers. This is to allow for flex and compliance in the suspension and "should" allow the angles to compliment each other under load.

Mike

After seven years of owning our "MX", I'm still wrestling with this topic. Our ZZ4 is backed up with a G.M. #TH350 ... feeding an 8" FoMoCo {Auburn 3.25:1} rear-end c/w drum brakes, 5 stud on 4.5" pattern and 275/60x15 tires. The four link has non-adjustable, "BBK", lower control arms and adjustable, "Edelbrock", upper control arms. As a preventative measure, the universal joints are replaced each cruising season ... until we get the drive-shaft angularity issues fully resolved !!
Jimbo