I rang Bill Eldridge, a member of the VDC and a very cluey Chev 4 man, who later went on to start a full time vintage repair business, still going strong in 2011. Bill believed it may have been weak or broken springs on the pressure plate, and suggested a modification to make the clutch more user friendly and serviceable with modern parts. Why not, as Bill knew more about Chevs than I could learn in two life times, and I thought, it's out of sight so it won't detract from the original appearance of the vehicle. So I pulled out the gearbox, removed the pressure plate, clutch plate and flywheel, and headed off to see Bill at Noble Park, a South Eastern suburb of Melbourne.
Bill's process was as follows
1. The original Chev pressure plate (fig 1 and 2.) was discarded, to be replaced by a Valiant (Chrysler) unit (fig 3.)
2. The flywheel which incorporated the housing for the original pressure plate was machined back from approx 2 7/8 inches to 3/4 inch (fig 4,5,7,8.)
3. The flywheel was drilled and tapped to accept the Valiant pressure plate.
4. The carbon clutch throw out bearing was replaced with a modern throw out bearing.
The unit was assembled with the original Chev clutch plate which had been re-lined.
The results were well worth the effort. The engine revved more freely, seemed to pull away better at low speeds, and the clutch operation was smoother. Some believe that with the weight machined off the standard flywheel you may reduce the gyro generated pulling power, however, I never found this to be the case, and was impressed by the more responsive engine. At the time of writing this post (2011) the clutch modification is still performing as good as when it was first installed.
Fig 1. Original Chevrolet Pressure Plate
Fig 2. Original Chevrolet Pressure Plate
Fig 3. Valiant (Chrysler) Pressure Plate
Fig 4. Standard Chevrolet Flywheel
Fig 5. Standard Chevrolet Flywheel. The modified unit was machined from 2 7/8 inches to 3/4 inch.
Fig 6. Standard Chevrolet Flywheel.
Fig 7. Standard Chevrolet Flywheel.