I bought a used PBR rear end with aftermarket 3.73 Richmond gears. I am trying to evaluate the overall health of this rear end and determine what I need to replace before installing it.

Axle:
The end of both axles have a wear pattern that looks as if it has spun against something...maybe the pinion shaft?

The outermost surface "face" of the the axle splines have what I'll call chatter marks all the way around the slines from top to bottom. This is only on one of the axles. The splines that the axle plugs into look unaffected by this.

 

Here are pics of the pinion shaft. I was thinking at first that both ends have wear from the ends of the axles, but to be honest, I just don't understand how the inside of all this stuff works.

The pinion shaft looks as if something has lightly spun against it.

I have my current rear that I can use the axles and pinion shaft to swap in if they're good.

If anyone knows what might be causing this, please let me know. I'm trying to learn quickly so I can have her ready for summer.

 

Here are some more pics...

BTW. There were no metal shavings on the magnet or scattered inside, just typical metallic dust on magnet. The teeth on all gears I can see look good.

The axle bearings look good and the axles have smooth, even wear where they ride on the bearings.

Thanks for any help

 

That all looks pretty normal.

Whenever the axle is turning at a different speed than the carrier (going around a corner), the axles spin against the pin. The end of the axle always has signs of that.

The damage on the pin is from the spider gears spinning on it. Again, that happens when the wheels turn at different speeds... going around corners, or spinning one wheel. Since that's just a lame stock Auburn carrier, its effectiveness at limiting wheel spin, is somewhat weak.

You can buy a new pin for about $10. http://www.drivetrainspecialists.com...l-parts-1.html

 

EDITED:

Thanks Sofa,

Maybe I could file and smooth out the axle ends just a little and buy a new pin.
It looks like my drum axles fit if needed.

What about the surface of those splines on that one axle?
What would cause that jagged pattern?

Also, parts stores are asking if it's 7.5 or 7.625 for seals and bearings. From what I've searched it's 7.625 for the later years.
I give them the year of my car, but they still show two options???
Both axle seals and yoke seal appear to have been leaking, so I wanna get the right ones.

I hope it's good enough to replace seals and install. The goal for this car is cruiser status, "spirited" driving, quick accelerations, occasional street race, but no drag strip duties.
Thank You

 

The axle end pic is super blurry; can't tell much about it. Personally I'd leave it alone.

The splines are normal for cheeeeeeeeeep mass-produced cut splines. Note that where they have NEVER touched another part, they have that rough look; but where they've been engaging the side gears, they look kind of normal. I'd leave those alone too.

Yes it's 7.5 or 7.625". R1653TAV bearings if memory serves and 8660 seals. As long as it's not 7.75"; those are different.

If the yoke seal leaks, it's probably because (a) the yoke is worn where the seal rides on it, or (b) the bearings are bad, or (c) the nut is loose, or (d) all of the above. Odds of repairing it by just changing the seal are so tiny as to be quantum-mechanical. Frankly I'd leave the seal alone as long as the pinion is still installed; if it's out, see the axle seal install method I'm about to detail.

WHen you change the axle seals, DO NOT try to tap them in around the edge!!!! that is 100% ABSOLUTELY POSITIVELY IRONCLAD GUARANTEED to make it leak, because it distorts the metal part which in turn distorts the rubber part. Instead, lay it up against the seal bore, and hold a 2x4 up against it PERFECTLY STRAIGHT, and with one mighty whap of your BFH, knock it in there with authority.

If the carrier is out, tighten the pinion nut until it take about 36 in-lbs (3 ft-lbs) to turn it. That accounts for about 20 in-lbs of preload in the bearings, and the rest in the friction of the seal.

 

Just a couple pics of what's going on around the yoke.

It's dry as a bone in between the yoke and axle housing, where I believe the seals sets. I did scrape and brush at some gunk, on the rear, but still...
Not sure why the yoke is so damp compared to the rear end itself...


BTW: Yes, I do plan on cleaning it up and painting. It's a little rusty lookin'