I have the Dana 80 with factory 4.10s and a limited slip on my F350 PSD 4x4 DRW. I did not check the rear diff for quite a few miles (maybe 55K or so). When I finally checked, there was a small mound of fine metal shavings piled on the magnetic plug. The fluid level was only a fraction low, so that isn't the problem. I cleaned the plug thoroughly and checked it again at my next oil change (about 5K miles) and it had a very small amount of shavings. My question is what amount of wear should I expect from this axle (I assume some since it is HUGE)? There does not appear to be any play in the rear and I have yet to notice any problems from it.
I know this may be under the wrong topic, but I have yet to get a response under the drivetrain section.
Thanks,

 

From my experience some metal is fine. Well sorta! the bearings on alot of big rearends destroy themselves quite often. My 10.5 ford has 80k on it and an inpection revealed totally destroyed bearings....That made no noise at all. Thats most likely your metal shavings...You can go many miles with bearings that are lunched.
I'll bet I could of left them in mine for another 20k and wouldn't have known.. Alot of people who do lockers just replace the bearings..

 

Thanks, 99F350sd. I guess I'll eventually break open the rear cover....I guess it is time to change the fluid (97K right now). Do you think the bearing wear will be noticeable once I open the rear cover if that is what is wearing, or will I need to remove the assembly to notice?

 

Thats the problem you can't tell without pulling the diff..