Very Weird Throwout Problem/Noise

[29 Tudor]

This one sure stumped me... I have a '29 Tudor. When the engine/transmission was cold or warm, no noise. After the transmission got a bit warmer, there would be a very strange screeching or "whining" sound coming from the throwout bearing whenever the clutch was depressed. I removed the inspection cover and when cold, you could rotate the throwout bearing and it felt absolutely perfect. After it got hot, you could occasionally feel a "catch" in it.

Today I pulled the tranny (pulled the rear axle) and got to the throwout bearing. For those of you that wondered, the left picture is what the inside of the throwout bearing looks like. I was expecting to find a bad ball or separator but no luck. It looked pristine!

The next picture shows what I found on closer inspection... see the shiny spot on the brass colored ring? If you look at the collar, you can see where it was rubbing. Apparently when it got hot, it started rubbing on the collar a bit and caused the noise.

Now here's the question: I measured the ID of the brass ring area and it is only .010 larger than the matching area of the collar which means there is only .005 clearance. I am thinking of chucking the collar in the lathe and cutting a few thousands off of it to assure plenty of clearance.... any thoughts? I believe the only purpose of the brass rings is to "seal" the front of the bearing to the collar so greasing the collar will force grease up into the bearing.

By the way, with this bearing, ( a BCA) there WAS a path from the grease holes in the collar into the bearing. I don't know if some of the new ones are truly sealed but this one wasn't. I'm sure it was replaced when the running gear was rebuilt (not by me) some years ago.

Of course, the normal project creep has grabbed me and I pulled the tranny apart to inspect it. The cluster has a number of badly pitted teeth and the other two gears show some signs of damage as well so I'll be ordering all new (USA) gears and rebuilding that as well.

Any thoughts or comments on the bearing/collar?

Thanks,

Steve