915 Clutch Drag

[tiemeyj]

Hello,

I have 1974 911 with the early style 915 transmission that does not use the omega helper. I noticed when selecting reverse with the engine running (clutch in for at least 5 seconds) I can feel the input shaft turning and I get a faint grind going into gear. The shaft is not spinning fast like it would if the clutch were out nor does it feel like there is any real power being transmitted from the flywheel...it's just barely spinning. If I keep the clutch in and take it in and out of reverse, the shaft will start to spin once out of gear. The condition is intermittent but is there about 75% of the time. There problem seems more pronounced if the car is pointed down hill.

I have adjusted the clutch at the transmission end, checked and adjusted the clutch pedal stop at the cluster but no change in behavior. Any thoughts on a cause? Bent release fork or something in the pressure plate?

[yelcab1]

You need a new clutch.

[tiemeyj]

Yeah, funny thing is it supposedly is. Just one more item to add to the upcoming engine out list. Any idea what would actually cause the condition? I confirmed earlier today that it happens primarily on a downward grade.

[john walker's workshop]

Lube the mainshaft splines with a new clutch. Dry splines can cause this. The disc has trouble centering between PP and flywheel when it's disengaged so it drags.

[tiemeyj]

That makes complete sense. Thanks for the replies. I'll post an update once I get a new clutch in.