What's on Your Plate?
Rebuilding a vintage clutch disc
Earl Duty - December 06, 2012 10:00 AM
After removal of the clutch and pressure plate, a close inspection finds the metal fatigue cracks, which caused the clutch system’s inability to release.
Here, shop tech Jeff Roth measures a worn out pressure plate prior to beginning the rebuild process. Accurate measurement before and after a rebuild insures proper balancing of the assembly.
When a clutch disc is worn to the point of rubbing these rivets, slippage will happen.
Wall after wall of new clutch facings. If they don’t have your clutch facing in stock, they can custom build one from blank stock.
They also carry a massive inventory of clutch kits.
Need a clutch release fork? They carry a good supply.
They can also resurface flywheels, both flat and bell type.
Our story begins with a call from Larry Clevenger, the owner of an original, unrestored 1938 Ford two-door sedan, with the 60hp flathead engine.
His problem: the clutch would not disengage when depressing the clutch pedal. This naturally led to lots of gear grinding when trying to put the transmission in any gear. An adjustment of the clutch rod had no effect on the clutch disengagement. After the challenge of removing the clutch assembly had been overcome, a visual inspection revealed that the source of the problem was due to a broken section on the clutch pressure plate.
In my world of replacing a clutch system, it is a normal procedure to replace four basic parts to the assembly, i.e. clutch pressure plate, clutch disc, clutch release bearing, and the pilot bushing (or bearing). You should also have the flywheel resurfaced.
After an Internet search, plus phone calls, I located a NOS (new old stock) 8½-inch pressure plate, new clutch release bearing, and pilot bearing. The challenge of locating an 8½-inch clutch disc would finish our parts round-up. The four suppliers of clutch parts I contacted simply said “send us the old clutch disc, and, we will rebuild it. We have no new 8½-inch discs for that application.”
I recalled from my 12-year employment at Smedley’s Chevrolet in Vandalia, Ohio, there’s a company we had used for clutch rebuilding called Dayton Clutch & Joint. A phone call later with Keith Knight (company president) resulted in him saying, “Sure, we can rebuild that.” Well, this was too easy, in that I live approximately 30 miles from the facility. Long story short, I dropped the disc off and it was rebuilt as good as new. Had I not found a NOS pressure plate, they could have rebuilt the old one (the owner of the car requested I use the NOS pressure plate).
Walter Knight started Dayton Clutch & Joint in 1956, and now over 50 years later, president Keith Knight and his crew are still rebuilding complete clutch systems. They also reline brakes, manufacture driveshafts, supply exhaust systems, etc. For a list of their services at both Dayton Clutch & Joint and Lima Clutch & Joint, check out their website.
Their clutch rebuilding section boasts, “ANY CLUTCH EVER MADE.” So I asked the question; how large and how small? Keith’s reply, “we do large 15½ by 2-inch spline double discs, and go as small as four to five inches. Cone clutches would need to be inspected by us for availability of specific rebuild material.”