Yes, clearly some serious overheating has gone on with your A clutch. You sometimes get the odd heat spot



but yours has severe acne, I’m afraid. You’ll see the friction plates have gone black (originally brown) at the same diameters as the heat spots on the steel plates.

The O-ring that seals the input shaft/A-clutch drum to the B-clutch drum has a very small section diameter and doesn’t look particularly robust for the job it has to do. This is the seal that fails when the bearing fails and puts the transmission into failsafe, so I’m pleased to hear that you’re replacing it.

You need to measure the shaft diameter and corresponding bore diameter of the bush at the end of the stator shaft because that also acts as a seal for the A-clutch. In my experience you don’t want a larger radial clearance than 25μm.







The groove that you’re indicating in the photo is just a shallow undercut for the grinding wheel to runout into during the machining of the bearing diameter on the shaft during manufacture. I must admit, it does look a bit more generous than normal, but I can’t see that this would cause an issue.

Phil