Triumph Repair: Spitfire trans slipping, clutch fork, clutch pedal

Question
Jim... Did a body off resto of 64 Mk1 Spit. Put in reman'd 4-spd tran from Spitbits. No overdrive. Had clutch pressure plate rebuilt. New throw out bearing.  Did all install work myself. Car's been driving normally for about 500 miles since completion.  Symptom now is that while underway, I'll accelerate and the motor revs up without noticeable torgue on the car.  Most noticeable if I accelerate hard--for instance, if in 3rd gear, punch it to pass.  If I back off, revs come back down and it seems to re-engage smoothly again. Have noticed symptom intermittently in all gears.  No grinding noises, no problems with staying in gear, no hard shifting. Clutch pedal travel is normal.  Any ideas? Larry in Panama City FL  

Answer
Larry,

It sounds like either the pressure plate isn't down tight or the throwout bearing is hanging up on it's slider in the nose of the transmission.

Either way the clutch disc isn't being clamped properly, causing the slippage.

Before tearing it all apart get the car setup so you can observe the clutch slave/clutch fork and have a friend push down on the clutch pedal to get a feel for the amount of travel.  When the clutch pedal is released there should be just a bit of free play in the clutch fork... if there's still a "load" on it then either the hydraulics are "stuck" (possible, not typical) or the sleeve in the nose of the trans is sticking (more likely).

Still, if there does seem to be a load on the clutch fork try opening the bleeder valve on the clutch slave and see if there's still pressure.  If there is then it's a hydraulic issue.  

Otherwise, I'm afraid you'll have to pull the trans again.


Cheers,

Jim