Just to be clear, you are certain the TOB is spinning continously, engaged or not?

 

yep, kind of a misconception. its always spinning, but when engaged via a arm or hydraulic set up, there is then an axial load on it, but its always spinning.

 

Ok, I may be confused here and need some help. I 'm a little thick. The TOB is always moving yes, however, when not working it spins with shaft it resides on, or eventually does unless it is dragging, so though it is moving the bearing is not really moving much at all and of course no load. So the only time it is really spinning ( at a different speed than the shaft) is when engaged and a little after disengagement. Am I getting this right or has something changed I am not aware of? I know Irish informed me of a differing design in actuation. I would be amazed if an unlubricated bearing could last so long, but then again my phone scrolls through text using my eye movement.

 

So happy my post was not responded to as it caused some fact finding. Indeed the throw out bearing is always moving (provided car is not in n) just as we on earth are always moving even if we are standing still. "Spinning" may be a bit confusing to us simple folk. Turning with the shaft is more accurate and easier to understand. Hopping on the 9n to plow the back 40 now.

 

Actually, its not like us sitting on the earth and the earth is spinning. its really spinning and getting wear with every revolution of the engine flywheel. (i.e. when the engine is running )
the reason is that the TOB is tied (fixed) to the flywheel.. the flywheel spins, the TOB inner part that is attached to the pressure plate, which is tied to the flywheel , spins. the outer portion is fixed to the bell housing and doesnt move. (it has the lever arm , that also is attached to the bell housing and activated by the slave cylinder or has a network of hydraulic hoses attached to it, but either way, it doesnt move)...........so, there is a bearing that separates them that is always being used and is wearing. there is MORE wear when you engage the clutch, because of the axial load on the sleeve that is tied to the pressure plate to engage the clutch. regardless of it being in neutral.. (shaft spinnning), in gear, (shaft spinning), or with the clutch in. (shaft not spinning in neutral, and spinning at the speed of the appropriate gear , if in gear).

So, you see the TOB is always spinning and being worrn. the shaft inside of the TOB is floating through the inner diameter and not generally wearing or touching anything on its outer diameter.

 

I am confused. How does the throwout bearing touch the flywheel?

 

I get it now. Pics in manual helped. Thank you for your patience.

 

Its not touching the flywheel, but spinning with the flywheel, because the pressure plate is bolted to the flywheel. the "spinning " part of the TOB is fixed to the fingers of the pressure plate, so its always spinning if the engine is running. (regardless of the shaft running through it is at the same rotational speed or stopped.


I think you get it now. its not that obvious, and so many people think that the TOB is only worn when the clutch is pressed in, but actually, its always spinning, but the axial load changes when the TOB pulls the fingers back off the pressure plate to release contact on the flywheel. noise can occur when you press the pedal in , if there is a bearing problem, as the problem will make more noise when the bearing is loaded. the other noise that you can hear if you let the clutch out in neutral, is the torque tube shaft spinning..... it has bearings located in the torque tube that can go bad.