Reply to "Clutch Slippage"

Doug is right; most likely either the clutch friction surface is worn too thin, or the assembly is badly mis-adjusted, or something else is mechanically broken. Oil contamination from a leaking rear main seal or from a front ZF seal is most common but is not necessarily fatal. High performance motorcycle clutches run submerged in oil baths. But I recently worked on a Pantera who's clutch "slipped badly".... because the clutch bellcrank lever where the slave cylinder attaches was misadjusted in at least 3/8"! This meant the clutch was half- released at all times. With a LOT of trouble due to the pressures involved, I managed to get the bellcrank disconnected without breaking anything, and moved it THREE splines on the cross-shaft. What was left of the clutch then worked fine. So first, check your adjustments.