Throw out bearing

[Kernopelli]

I am replacinging the throw out bearing on my MTE 2000D and need some advice. I had replaced the entire clutch assembly before and this T/O bearing went out after just a few years and when I took it apart I didn't pay any attention to which way the bearing was oriented on the hub and I am now wondering if I had put it on backwards the first time and this led to it eventually allowing the hub to tilt downward on the trans shaft and the bearing being crushed/deformed and the hub to be wallowed out. I turned a new hub on the lathe and milled the rest and it turned out very well and now I am ready to reassemble and need some opinions.....I took two pics of the bearing and need to know which side of the bearing goes against the pressure plate. The first pic has a slightly rounded profile with the race recessed. The second is flat with the race flush with the top, which side goes against the pressure plate?
Thanks

 

[dex3361]

I would think the bearing to the left would go toward the contact surface. How thick is the material on the left bearing surface. or is it pressed metal?

 

[Kernopelli]

I thought I must have inadvertently thrown the old bearing away but I just went out and searched...and searched for it again and found it under the work bench. I couldn't imagine that it wouldn't be the rounded side simply because it was "different" and it must be made that way for a reason. However, at this point I want to make absolutely certain it is installed correctly. From looking at the old bearing, apparently the way I had installed it the last time was with the rounded surface facing the pressure plate. This would also make sense after measuring the thickness of the metal of both faces of the bearing ( I was able to do this since the old bearing came apart when I took it off the hub), the rounded side (left pic) was .183" at its thinnest point and the flat side (right pic) was .036". Stands to reason that the thickest material would be the used for contact against the pressure plate.

I am still not certain exactly what happened. The hub holds the T/O bearing and is supposed to be centered on the transmission shaft and the pedal forks push it forward against the pressure plate. When I took it apart, the hub was still engaging the forks on the back side, and pretty well centered but cocked downward towards the front. This caused it to rub on the transmission shaft and wallow it out badly. The T/O bearing was pushing unevenly on the "fingers" of the pressure plate and the bearing failed and messed up the fingers. Which caused which is the mystery. Fortunately the trans shaft was not hurt. It obviously took a while to do the damage to the hub and you would have thought that it would have been making a terrible racket but there was no noise at all except for a short period right before I tore it down and that sounded like a bearing squealing. After tearing it down, that noise was clearly a seized T/O bearing rubbing against the pressure plate when the clutch was engaged. The clutch action was also showing signs of a problem by this point as well.

All in all, it could have been much worse. The new hub turned out very well ( I'll have to post some pics), doing some searching for a new one turned up nothing so I was starting to get a little concerned and the trans shaft wasn't hurt. Now that I feel certain which way the bearing goes on, I'll be back up and running this weekend.
Thanks Dex