I had a driveshaft made for my 94Z M6 with a Moser 12 Bolt with the 1350 yoke. I disconnected the driveshaft and pushed the shaft on to the transmission spline as far as it would go. Then I measured the distance from the back of the U-Joint to the nearest part of the pinion yoke. I measured a hair over an inch.

Did I measure correctly?

Is an inch enough to allow for launches or hard shifts?

What is an ideal length for driveshaft travel? Does anyone know what the driveshaft travel length is for a stock setup?

Does anyone know the distance from the base of the transmission spline to the end of the spline? (It appears that there is some sort of rubber seal or washer against the base of the spline where it connects to the transmission).

I measured the inside of my driveshaft yoke and it measured 4.5 inches. The distance of the end of the transmission spline to the edge of the rubber boot was one half inch. With the driveshaft installed, I measured 1/4 inch from the end of the rubber boot to the outside base of the driveshaft yoke? Do these measurements appear to be right?

A safe New Year's Holiday to everyone.

 

To measure driveshaft clearance, the rear axle needs to be at stock ride height.... not at full drop with the car jacked. With the rear axle at normal height, pull the caps off the rear u-joint. Slide the DS forward until it stops. The distance moved is the clearance. On a stock setup, that number is about 1/2". For a major power adder, that number needs to increase to 1".

All this is based on input from ACPT, Mark Williams and Steve Spohn. It became a major issue when ACPT claimed my carbon fiber DS failed because it was too long. In fact, it was exactly the same length and exactly the same clearance (1") that my Mark Williams replacement DS had, and which worked fine with an M6, Street Twin, and 5K clutch dumps on 28" slicks. ACPT refunded my $700 .