ZF Trans

How many threads are showing on your clutch slave adjustment?? It could be marginal when cold, and when things heat up, the clutch just does'nt disengage completely. Marlin.

The ZF is arguably the strongest part of your car. Jr Wilson swapped a bored 'n stroked Boss 429 (538 cubic inches) into his race Pantera, The ZF handled the estimated 900 horses & 600 ft-lbs torque just fine. Your grinding most probably indicates the synchros are badly worn. ZFs use steel synchros which wear slowly, but as they wear, they also wear down the mating gear-cone. So, one cannot just replace the synchro ring to fix this; the entire gearset plus the synchro must be replaced. This is why I've been preaching about using long-throw clutch slave cylinders to lessen the drag on the synchros while shifting. To diagnose this correctly, you'll need to pull the ZF and send it to the only FACTORY reconditioning shop on the planet, RBT Transmission, in So-Cal. Lloyd will disassemble the box & check it over. Website is WWW.rbttrans.com. He is also the only one who has new parts available. In the meantime, you should start negotiating a 2nd mortgage....

Jack and Marlin Jack,

Thanks for your responses. I was afraid of the answers! However, the car is worth it!

Later,
Daron

To put a positive spin on this situation, if you pull BOTH the engine and ZF together, it gives you the opportunity to do some preventive maintenence during the bad-weather time:
1)- pull the gas tank & check behind it for evidence of rust starting in arguably the most difficult place on the car to fix. The chassis braces & quarter panel are often involved, and the OEM gas tank was installed unpainted, so it also has been known to rust through.
2)- cut out & replace the welded-in e-brake bracket & the crossmember under the engine's oil pan. Removeable versions were optional after '75. Then the oil pan can be removed without pulling the engine.
3)- before sending the ZF away, check your fluid level via the fill plug under the shifter box on the side, and safety-wire the ring gear (RBTTRANS will do this on request)