Clutch Materials

[swall]

We supply Cr-Si springs for a spring loaded clutch disc for class 8 trucks. The spring life was not satisfactory, but we fixed that by nitriding them. Now, the customer has a perception that iron oxide fretting residue is a concern and is looking for solutions (to a non problem IMHO). Fretting occurs between the springs and the pockets in the clutch disc as well as the driven and non driven discs. Ideas I have come up with include TiN of the steel disc, dry film lube on the springs and/or steel discs, laser hardening of the spring pockets, slurry deburr of the spring pockets. Anybody got any other ideas for surface treatments?

 

[unclesyd]

On several occasions I've used bronze, either applied by brazing or a disk brazed to the socket material at the bottom/face of the socket to alleviate wear and recovery of worn spring sockets.
I have also used bronze to recover some very worn clutch housings were the OEM parts were steel plate on steel housing.