Axle seal is leaking again in my 1971 Riviera after 2 years. I previously replaced with National 2689S seals. At that time, I noticed the entire axle could be pulled/pushed out/in when bolted in place, so I put in spacer shim behind bearing cups/races to eliminate slight endplay between new tapered roller bearing cone and cup. I have a set of original 1972 Riviera axle shafts with straight roller bearings and GM 1245504 (alternate 1236163) seals. These came from the donor 1972 rear axle assembly that I got my posi diff from. Bearings and seals were known good at time of removal. I'm considering installing one of these axle assemblies while my original axle is out having a new seal installed. I wonder if the straight roller bearing setup is better, less likely to allow the endplay? Also, I've found some NOS GM 1245504/1236163 seals available and wonder if they'd be a better quality and fit than the aftermarket seals?
Well, after some extensive research I've answered my own post. My seal separated into inner and outer shells free floating. The side rubber bond broke away. See second and third photos. New 2689S seals are generic garbage. Original GM 1236163 seals are much better. The seal that one supersede, GM 1245504 is better yet. See first photo, in order top to bottom. Fourth and last photo is of an original 1972 axle showing factory, quality seal. I have extras now of the 1245504 seal if folks would like them. Contact me outside this post.
Yo answer your question about the bearing styles: the straight roller bearings will operate with endplay because they can’t unseat from the race. Your last photo shows a Timken bearings/seal combo,which would have been replaced at some point. Should be a SET10 if you are using the seal that you mentioned.
Second and third photos are of my '71 Riv axle with a BCA bearing assembly installed 10 years, 10-15k? miles ago. Fourth photo is of an extra axle I have from a donor '72 Riv, no idea if orig bearing or not. I will be replacing mine with the Timken SET10 consisting of U399 cone, U360L cup, and K426898 ring.
What I have found is that it is a crap shoot when you order a 2689S or similar seal. You can get two identical boxes,but each will have a different looking seal inside. I went through this hassle with the last one I did. I ended up buying 4 of each part number,until I got the two matching pair that I wanted,which looks like the seal in your last picture. I don’t trust the one that is all metal,with a rubber band around it,and you have shown why.
Well now you all know what even the builders have to deal with... IT is tuff out there. take your originals and always measure before buying parts. Jim J D Race This is the same deal with the A9 Set9 stuff for the A-body cars too. Terrible out there.
