Hi folks,

So, the transmission in my 91 NA exploded recently. I procured a replacement transmission, and I noticed that the release bearing on it looked a bit odd.

Have a look:
https://i.imgur.com/uJcNUbL.jpg

The one on the left is the old release bearing that I had, pretty sure I got it from Mazdatrix < 50Kmiles ago.

The one of the right is the release bearing that was on the replacement transmission. Is that a compatible part? There's no part number on it, but it does look to be made by NTN.
I have a minor, worried suspicion that it's an S4 transmission release bearing? If so, ugh, well, then I need to go and read up to be sure of all the S4/S5 transmission compatibility (shifters, clutches, etc)

This is just something that I wanted to be sure of before going to all the trouble of putting the transmission back in.

 

Look at S4 vs S5 throwout bearing.
Clutches 83-92 (225mm non-turbo)

 

I did look there, and couldn't quite tell from that little picture if that's what I have in hand or not, but the existence of different parts if what gave me the suspicion.

Anyway, after some more searching, I see that Rock Auto has a photo of it, and that's indeed an S4 throwout bearing: http://www.rockauto.com/info/BCA/BCA_614079_FRO.jpg

Now ... ****. Now I need to figure out if I can put this back together with the pieces I have, since this seller deceived me.

 

you can run either one,they mount on the fork the same way and do the same job.

My Concern would be if you are replacing the Trans,why put in a USED Throw out bearing?
Rule of thumb is if you drop the trans,replace all bearings.Why have to drop it again,right??

 

Yeah, I know what you're saying, but I don't really want this to spiral out into a high dollar job. I could change the clutch disc and such at the same time, but it was all done < 50K ago ... actually, probably less than 30K, now that I really think about it.

I mean, I could go to all the trouble of getting it ship-shape and Bristol fashion, and then something else on the car will explode :\
I just want to slam it all back together and keep on rolling until then.

Oh, yeah, here's what happened to my first gear: imgur: the simple image sharer

Thanks for the info on the use of the bearings. I'm always worried about small changes in sizes, dimensions, and clearances. Mazdatrix does show a different looking clutch plate for the S4, too, so I'm a little worried about it. And a different part number for the fork.

And I don't have an S4 shifter. Or an S4 crossmember. What a humbug it's going to be to ship this thing back across the country ...

 

You can put an S5 shifter in an S4 and vice versa.
If you plan to put an S5 Trans in an S4 then you need the crossmember that the transmission came with.
You can't put an s5 trans crossmember ON an S4 trans..and vice versa.
Both Crossmembers bolt to either car the same way.