Pinion gear rubbing differntial case

[merc123]

Got almost 120k on the truck. Bought it with 95k about a year ago. The speed sensor went out so I was going to change the diff fluid while I was at it. Pulled the case and got these wear marks on the case. No gears are chipped or broken but it looked like maybe the very end of some of the pinion teeth might have worn down from rubbing. What causes this?

Also, the "grooves" were light and almost couldn't feel them on the top but they were pretty pronounced and enough to catch a finger nail on them toward the bottom and close to the pinion.

[Bad Night]

Looks like it was installed incorrectly once or had the pinion bearing go clear out .

[Bad Night]

Actually a carrier bearing could have caused that too but either way that's a tough one . If the pinion gear was installed with too much shim it could have rubbed there .

[GAS]

looking at the wear pattern or contact patch on the ring rear teeth will tell what has moved to cause this.

[merc123]

I believe everything is still straight from the factory, but I could be wrong as nothing showed up in an OASIS report. The fluid, for 120k miles, actually looked relatively clean. You could still see through it as it drained and was actually 10x better looking than engine oil that comes out.

The wear pattern on the teeth look fine. A buddy of mine came by to look and said it looks like they might have messed it up from the factory. I do have a light whine when on the gas and it goes away when I let off the gas. I'll also know more when I get the new speed sensor installed to see how much metal shaving sticks to it. The old one had a little bit on it.

[merc123]

Stuck the truck in neutral and shook the drive shaft a little and it had some side to side motion and you could hear a clunking so I'm assuming there may be some bearing issues.

[Fulltime]

I had the same thing happen to mine. I m in the process of changing the bearing. The pinion was loose. It would move from side to side and up and down. Seems like the pinion nut came loose. The bearing look good but I m changing them just to be sure. The ring and pinion teeth show no wear.

[merc123]

Swapped out the rear for a junkyard one just to get the truck going again. Now I just gotta fix the ABS light and no speedo issue. Going to tear into the rear end to clean out the metal shavings and redo the bearings later on then swap it back in.

[BryanH]

Hate to hi jack but I have a question. What made you check/change the speed censor? Did something happen?

[merc123]

ABS light, flashing O/D, no cruise, no speedo. The problem turned out to be a ground wire up by the driver's side headlight. Just found it tonight!