The rear end in my 71 442 Convertable is an O-type posi unit and when I removed the rear axles, the bearings were sealed type not wet like in most rearends. My question is, is this a good set up? seems like it would cause problems over time? Also, I read in the manual that in order to replace this type of bearing you have to cut off the retainer and press in a new one with the new bearing. Any one know who would sell these retainers and/or bearings. I have never had a rear end like this one.

 

What you have is an early style O-Type that uses the sealed axle bearings. That design was superceded in 1970 with the open tapered roller bearings that were also used in the '71-up corporate 8.5" 10 bolt rears.

It's a good setup. I have one (a '68 3.23 limited slip) under my car. Eventually the bearing grease would dry out, but I think that would take quite a long time. I got the rear in the mid-80s with the original bearings and they were still good.

As for bearing replacement, it is the same as on the newer rears. The bearings is pressed onto the axle shaft, and then a retainer is pressed on to, well, retain the bearing on the shaft. This is the same as the 10 bolt rear. Removal requires the retainer to be cut or split so it essentially falls off, then do the same for the inner race of the bearing.

The bearing you need is a RW-507-C. There's a thread about this right now: https://classicoldsmobile.com/forums...l-bearing.html

Replace the seal while you're in there - it's part number 8594S. Both parts were available at the local auto parts store the last time I replaced mine.

I had an issue 7-8 years ago where the bearing I replaced in the late 80s started slipping on the shaft, eventually cutting a groove that required shaft replacement (Brian Trick helped me out with replacement shafts). I read an article on bearing replacement that even though the bearing is pressed on with a lot of force (20 ton press), it should be "glued" to the shaft with some Lock-Tite to prevent it from eventually slipping. It makes sense based on my experience.

 

Thank you Kenneth, great information, I am kind of disappointed its not the original rear but sounds like it will be ok.

 

I look at it this way - the corporate 10 bolt was used under all the GM cars, but the O-Type 12 bolt is uniquely Oldsmobile.