TowRig.com - Diesel Discussion and Tow Tech

I just dropped the cover on my D80. This thing is f'ed up pretty good. It is a D80 3.55 L/S rear axle with 79,000 miles on it.

The pinion is pretty chewed up and every one of the ring gear teeth has a chip in it. The limited slip carrier looks like it has been chewed on quite a bit by something.

What would cause these kinds of problems in a D80. This is the rearend that is supposed to be bombproof but it looks like someone set off a bomb inside the damn thing. http://dieselram.com/ubb/confused.gif

There are very few metal shavings and no big chunks of metal in the housing which tells me that this probably happened when the previous owner had it and that he cleaned it all up and traded the truck in. I have had the truck for the last 7,000 miles and have not noticed any problems with the rearend but this thing is wrecked.

Any ideas what would cause this? I can't see any teeth ripped off the ring or pinion just alot of small chunks and chewing. Thanks

Harley

Wow, yes the D80 is fairly bullet proof. Have the dealer check it out, maybe you can get a rebuilt differential under your service contract.

As far as what would cause it, maybe bad pinion bearings or carrier bearings, but you should be able to hear and feel that. Sounds like one of those "Poo" happens...:doah:

This is what happens when you tow way over your GVCW and/or don't service your axle regularly. My money says that the dealer cleaned it out before selling it as is. Sounds crappy, but you should have some shavings on that magnet. Not a ton, but some is normal.

There were some metal shavings on the magnet this time and one other time I checked the fluid level. They weren't anything I havn't seen from my 14 bolt FF in my offroad truck. When I dropped the cover and saw chips in the teeth like that I expected there to be alot of metal in the bottom of the diff. There wasn't anything even down in the bottom lip of the diff that the D80 has.

I might expect this from a diff with 200,000 miles or more that had seen some heavy towing but this truck only had 71,000 miles and had no visible signs that there has ever been a 5th wheel or gooseneck hitch installed on this truck. :confused:

Harley