T-Series Clutch Release Bearing

[R6MGS]

The mechanic has the clutch out on the 1980 MGB LE we supplied him with a complete new clutch including a new grafite release bearing....upon inspecting the existing release bearing he told us that it has a roller type bearing in it.....just to be safe we decided to buy a roller type bearing(from a local LBC parts supplier) and bring it to him.....the new roller bearing is exactly the same as the grafite one that we originally bought(moss part #190-300) except it's the roller type....the mechanic then compared the new roller bearing to the old one wich is still different.....the old one looks like an aftermarket replacement, it's American made and says "green" on the outer rim....the center hole on it is slightly smaller that the other two new ones but the mounting points to the fork are exactly the same...the old one is also sits up slightly higher than the other two new ones when you line up both mounting points side by side.... it still seams to be in good working order. So the question now is do I put the new roller type bearing(OEM style), the new Moss grafite type bearing, or put the old aftermarket bearing back in?.......I'd hate to make the wrong decision and have to do this all over again!

Thanks
Zack

 

[Keoke]

Question! ,Is the roller type bearing in a black plastic case??---Keoke

 

[maynard]

All B's came from the factory with graphite throwout bearings. The roller bearing you have is aftermarket.

Some roller bearings had problems of flying apart. I don't know if your's is one of them or not.

As far as the hole diameter goes, if the surface of the bearing that contacts pressure plate like it should, the rest is academic.

Which should you put in? Up to you, but I have always used graphite with no problems at all.

 

[R6MGS]

YES! Keoke, it's the one with a black plastic case!...why??

 

[Bugeye58]

Zack, Maynard is correct in that the standard release bearing was the graphite type. I have never had any problem with either the graphite or the roller bearing.
I run the roller type, in the black plastic case, in two Midgets, a Sprite, and both the race cars, and have never had a failure.
If the distance between the face of the bearing surface and the centerline of the pivot is greater on one bearing, you will experience clutch activation at a higher point in the pedal arc as previously. And, vice versa, if the dimensional change is in the opposite direction.
Unless the bearing has very few known miles on it, I would replace it as a matter of course while everything is apart.
Whichever you should decide to use will be correct. I would also assume that the flywheel surface is in good condition. In the event that the flywheel needs to be resurfaced, it may be to your advantage to use the bearing with the greatest distance between the pivot and the bearing surface, to allow for material removed during the flywheel resurfacing. I've got a '72 Midget that has had the flywheel cut one too many times, and the clutch won't disengage until the pedal is near the floor.
The next time I have it apart, it either gets a new flywheel, or I shim the old one back to the correct distance from the crank flange.
Jeff

 

[R6MGS]

Thanks alot for your advice it's REALLY helped.....the flywheel was just resurfaced so I think I'll stick with the one with the black plastic case.

Thanks again!
Zack