check out these different throwout bearings

[pauleyman]

I thought this was kinda interesting as I had not seen this before.
The bearing on the left is an NSK parts store bearing that comes in a lot of clutch kits. Notice the sharp edge.
The middle is the standard plastic lines MD749998 OEM also made by NSK.
The right bearing I just received with an exedy kit for my sons 2006 lancer ralliart (uses same bearing) and it's a koyo rct322sa. Notice it doesn't have the sharp lip.
I was going to use my OEM and buy another given I didn't want to use a sharp edge bearing but I'm going to use this koyo on the lancer. It's a light clutch and it's gone
185k on who knows what.

Thought this was interesting.
BTW the box also has numbers 70151 and m1902
I also find it interesting that even though both are NSK none of the part is remotely the same. The outer shell, the back plate. All different.

You must be logged in to view this image or video.

 

[mitsubishikid]

I thought this was kinda interesting as I had not seen this before.
The bearing on the left is an NSK parts store bearing that comes in a lot of clutch kits. Notice the sharp edge.
The middle is the standard plastic lines MD74999e OEM also made by NSK.
The right bearing I just received with an exedy kit for my sons 2006 lancer ralliart (uses same bearing) and it's a koyo rct322sa. Notice it doesn't have the sharp lip.
I was going to use my OEM and buy another given I didn't want to use a sharp edge bearing but I'm going to use this koyo on the lancer. It's a light clutch and it's gone
185k on who knows what.

Thought this was interesting.
BTW the box also has numbers 70151 and m1902
I also find it interesting that even though both are NSK none of the part is remotely the same. The outer shell, the back plate. All different.

You must be logged in to view this image or video.

The middle one is the one RRE pointed me towards getting a few years ago, they said they told me they use it on all their cars, the reasoning one of the guys over there told me was that the metal ones might add more wear to the aluminum input shaft surface, so I took the advice and so far had no issues running the plastic inner sleeve ones on all my cars.

 

[Kryndon]

I recently installed the NSK unit on the left with the sharper sleeve edge. What I liked about it is it has a deeper channel inside for the lubricant. So what I did was I just filled that part with some nice cv joint grease until it sat flush then wiped the remaining away so it wouldn't overfill. That groove would help keep the grease in there and reduce wear on the input sleeve. In any case, all these are good options and way better than the other alternatives which are physically smaller in diameter and use smaller ball bearings. Not good for a long lasting heavy pressure plate or dusty environment!