VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Chevrolet 1928 new clutch failed

Anyone seen this? New clutch 2018 from Gary Wallace. All splines are cut of.Gear shaft spline are in good shape. Whats happen?

Looks like failure of the metal.

Yep definitely a material failure. obviously the hub was too soft a material. In your case that is a good thing as your input shaft survived. Go back to the supplier with it.

As a once heavy duty truck technician, I have seen this happen solid center clutch shortly after a clutch replacement. This can be caused by putting a new clutch disc on a shaft with excessively worn splines. This allows the splines on the shaft to bang back and forth eventually pounding out the splines in the hub as the splines on the shaft are harder than the metal for the splined hub.

I concur. It's getting harder to find a transmission with a good spline shaft.

I have seen haft with excessively worn splines. But not here. The splines are very fine.

If your transmission support isn't properly aligned on the center of the crankshaft, this kind of wear can occur. Also, torsional vibration can cause this kind of wear. Dampened discs are the cure for that (it's mainly to save the hub splines and the input shaft splines to the transmission.)