We are having problems getting the hydraulic clutch to work on our '65 W200 with 383. The NP435 that was previously in the truck was very worn and we had a NP420 laying around in the garage so we decided to switch to the 420. I rebuilt the clutch master and slave cylinders and they are working good. When pressure is put on the clutch pedal it immediately pushes the rod out of the slave cylinder and engages the throwout bearing/pressure plate. There is a small gap between the plate and clutch which looks correct. The problem comes when you try to put it in gear while the motor is running. I adjusted the bolt on the slave cylinder almost all the way out and I was barely able to put it in gear while the pedal was at the floor. We also checked to see if somehow the clutch was in backwards but it was the correct way. We took a few measurements and the input shaft on the 420 is about 0.25" longer than the 435 and the shaft that the throwout bearing runs on is about 0.50" longer on the 420.
We were told to put the transfer case in neutral, put the transmission in 4th gear and push the clutch in. It should be able to turn if the clutch is free but it doesn't. We are out of ideas. Don't know if anyone else had the same problem in putting a 420 behind a big block...??
Any help would be great.

Rob

Mountain Springs Power Wagon Service, Paso Robles, CA

1962 W100-340-LU2 winch
1964 W200-340-LU2 winch
1964 W300-318-LU2 winch
1965 W200 Crew Cab- Cummins Diesel