What's up with my throwout bearing?

[Baby]

Ever see scoring like this?

[Walt Fricke]

Looks like you will need a new guide tube (the part on the transmission) too.

What do the diaphragm spring fingers look like?

[john walker's workshop]

some lube would have been good.

[Baby]

Thanks for your responses. Everything else looks normal from here. I’ll have a closer look when it comes apart. The guide tube looks good. The black finish is worn away, but otherwise it’s smooth and unworn. Hard for me to imagine what would cut into it like this.

The clutch and associated components have only a couple thousand miles on them. Anyway, I’m thinking maybe the gouging happened during the brief clutch cable adjustment process and it wasn’t an ongoing thing.

John, does the TO bearing look useable, or should I replace?

[Flat6pac]

Sure looks dry of grease..
Bruce

[Baby]

Sure looks dry of grease..

Bruce

Bruce, You are correct. I assume the burning off of grease preceded the grinding of metal.

[Walt Fricke]

I assumed that Mr. Baby had cleaned off all the grease on the TOB. For instance, there is none in the release fork groove. That doesn't need much, but there is usually some and I think there should be.

If he didn't clean anything, then none was applied when last the transmission was mated with the engine, and the mystery is solved.

[Baby]

Walt, I didn't clean a thing before snapping those pics. But I can assure you that last March when I did the clutch job I greased both the guide tube and the fork ends. There is still plenty of grease on the fork ends. Now, I didn't slop it onto the guide tube. Instead, I applied a thin, even layer. Maybe that was my mistake. If the problem is a lack of grease, that's no big deal, and I'm thankful the issue isn't related to something more serious, like metal-eating termites.

PS: I was in Boulder a few weeks ago visiting friends. Great town!

[DRACO A5OG]

I had a "Gritty" feel on my clutch travel, a dry T/O and Guide was the culprit. Replaced and Lubed, all smooth now

[RWebb]

did you use a high-temp. grease?

[Walt Fricke]

Well, I usually just grease the release fork tips, too. But I tend to end up with some grease in the groove, which I assume was spread there from the fork.

And I don't think you need a whole lot of grease on the guide tube, either, normally. I smear some on with a finger, and do the same with the TOB ID.

My suspicions were directed toward the TOB rotating a lot more than it should, given how dry things are.

Are you going to take the TOB off so you can inspect the diaphragm spring fingers for wear, and look over that funny spring washer that goes in there?

My hypotheses as to why parts which are not supposed to rotate (much) have done so are either that the bearing is, for some reason, tight. Or that the bearing is not tightly enough held to the diaphragm spring, allowing it to slide around. Though this last doesn't have quite as direct or obvious a path toward rotation of the outer "fixed" bearing housing.

For hypotheses, you are welcome to substitute "guesses." For a while I was installing the funny washer part of the TOB the wrong way (and perhaps without enough or a thick enough flat washer), and I supposed that was why I was getting escessive diaphragm spring finger wear. But I wasn't having the wear on the TOB and guide tube you have noted.

What grease did you use? I used to use Bosch distributor point block grease until the tube, left over from the days of having points, ran out. After which I have tended to use whatever I am using on the CVs, which seems to do the job. Hard to imagine you used an inadequate grease, though. You'd think any reasonably high temp grease would do.