Repairing A Friction Clutch

REPAIRING A FRICTION CLUTCH

JAMES E. TAYLOR

WHILE ON VACATION this past summer on my Triumph T-120 I gave my clutch a great deal of abuse while riding in the woods of mountainous western North Carolina. At that time, however, damage to the clutch was not apparent. After my return to Florida the clutch began to seem more reluctant to disengage until finally it became impossible to release it.

Examination of the friction discs indicated that the cork patches were charred and that the bonding had deteriorated to the extent that the cork patches were peeling from the discs. With many of the patches missing, the clutch plates ran untrue, resulting in severe binding.

Having some experience in the use of epoxy resin as a bonding agent, I decided to attempt the rebonding of friction material to the discs. Shopping around for a suitable material I found some cork sheeting 1/16 of an inch thick. The thickness specified in the owner's manual is 1/32 of an inch. I decided to use the 1/16 cork and then sand to the specified 1/32 after the bonding was completed. This would also insure the trueness of the completed disc.

All traces of the old material were thoroughly buffed from the discs using an electric drill with a rotary wire brush. Next I cut the required number of cork patches from the cork sheeting. With all five discs laid out flat I applied a thin coat of epoxy resin to the top face of each. Then I carefully placed the cork patches on the discs, covering each disc with a sheet of waxed paper and a suitable weight to hold the patches in place and prevent curling. After allowing sufficient curing time for the epoxy resin, I repeated the process for the reverse face of the discs.

After sanding to the specified thickness with a fine grain sandpaper on a large block, I liberally oiled the discs and installed them in the motorcycle. The result of the project is a clutch that operates like new for a cost of approximately $1.00 (a saving of $19.00) plus a couple of hours of my spare time.