[DanEC]

About the only thing I know about dual disk clutches is that there is some set-up and shimming that needs to be done on the clutch assembly (or at least checked and verified) to provide proper air gap when the clutch is pushed in. I assume either Brent or you did this?

I guess as painful as Bob's question could be - a way to check to see if that is the problem would be to back off the transmission bellhousing bolts about an 1/8 to 3/16 inch and loosen the transmission mount bolts. Then pull the transmission to the rear for increased clearance and then try pushing in the clutch and see if the rear wheels will turn.