OK guys, need some help here. This is on my 68 Barracuda.....i know...i know....but you guys have such a wealth of knowledge.
I posted a while back that I thought I was developing too much heat in my rear. It is a 68 Barracuda with a 8.75 sure grip. refresher- This was a new rebuild about 5 years ago. It has sat around since then until I put the car together last year. Of course the guy that rebuilt it really doesn't want to hear about my problems since he did it 5 years ago for someone else.
I have about 700 miles on the rear. It has now developed a leak in the front seal where the yoke is. I got ahold of an infrared temp sensor yesterday. After some driving, the center section was about 100 degrees. it was a hot day here yesterday and I checked my daily driver and that was about 100 degrees also. When I shot the front section where the yoke is, and I assume there's a bearing right there, it was 120 degrees. I had only driven about 8 miles. I think I've determined that is where the heat is comming from. Is there a bearing there? How hard is that to change? Do I need to pull the center section to do it? Anybody got any ideas or experience here?

I'm no axle expert, but...
Looking at the illustration from my '72 manual for the 8 3/4 axle; yes there is a tapered roller bearing there like a Chevy axle. Crush spacer between the two bearings. Why do you think you have a problem? Noise, vibration, roughness, etc.? Would require disassemby of the carrier. Major job. Special tools.

No need to be defensive about MOPAR; much better engineeing than GM back in those days...

Why do you think you have a problem? Noise, vibration, roughness, etc.? ...

well, it developed a leak and it has very few miles on it.

Leak maybe from seal damaged during installation, not installed properly, or surface of the "flange" (yoke) not smooth and damaging the seal. Seal and flange can probably be replaced with axle on the car, my guess. Good luck.

Is this the 741, 742 or 489 case? The 741 and 742 have a solid pinion spacer, and the 489 has a crush spacer. The bearing preload could be wrong allowing the pinion to move, which would cause the leak. The guy might not have used any sealant around the outside of the seal before he installed it, or he might not have lubed the rubber lip and caused it to burn up when you started driving it. There are several things that can cause a pinion seal to leak, but I don't think you have any heat problems. 120 degrees is nothing. Let me know which case you have and I'll go over some ways to change the seal.

thanks big gear head. how do i determine which case i have?

The casting number is on the left side of the case near the bottom at the front. The last 3 digits will be the number that you need.

2070742 thanks.