Help with sm465 clutch

[79vette]

I have a K5 with a 6.2 and turbo off a 6.5. I rebuilt the sm465 about 3 years and 20k miles ago.

When I swapped the 6.5 exhaust manifolds over with the turbo this year the clutch slave got real close to exhaust, and shortly after I started having clutch issues (intermittent spongy pedal, clicking when engaging and disengaging). I assumed the fluid was getting hot causing the poor pedal feel, and have been planning to redesign the hydraulics to move them further away, and ignored the symptoms for the last 500-1000 miles.

Yesterday I was wheeling out in the desert and lost the clutch completely. The truck moves if you start it in gear but the clutch will not disengage. The fork/throw out bearing is pretty far forward and the slave cylinder is stroked almost all the way out, and when I depress the pedal it either doesn't have any more slave travel or the fork is hitting the bell housing (can't tell as I'm by myself). As far as I can tell the fork is still clipped to the pivot stud. I can't see the throw out bearing but I can't imagine how the fork would have come off of that.

I'm out in the desert (have Internet on my Starlink), and am going to try to drive it a couple hundred miles home tomorrow morning when there's no traffic. I can start the engine in gear no problem but I don't want to be doing that in bumper to bumper traffic obviously.

Does this failure sound like the clutch is worn out already? Or can you think of anything else that would cause the slave to be extended all the way out with no travel left to allow the clutch to disengage? When these clutches wear out so they start slipping or do they just stop disengaging (like mine is doing)?

I'm going to pull the trans next week and will post back with what the problem is, but any insights you can share will help me limp it home safely tomorrow

[leegreen]

A worn out clutch would not be stuck engaged.

I assume you checked the fluid level in master?
Were you offroading, bouncing around or with vehicle on a steep angle so maybe the master took a gulp of air?

Or maybe some debris is between disk and flywheel or disk and pressure plate. I had a antichatter spring take a dump and a chunk was stuck between PP & disk, clutch would not disengage.

Hope you get home safe