2003 F150 screw 4x4 XLT. Bought in november with seized engine. Been going thru to make a reliable truck. Reman engine, fuel pump, Heater core, cv joints, been quite a project. Changing fluids in axles and did the rear yesterday. 9.75 rear axle. Got cover off, dumped fluid. Reached in to scoop out remaining fluid and found this. No silver paint just this one chunk. Axle has 187000. No funny noises, whine. Limited slip still works.



Any clue what it is, was?

 

Looks like a dog tag???

 

Possibly an ear off one of the clutches?

 

Didn't look at clutch pack pictures, but that makes sense. Mystery how it happened. Guess the rear diff is on the list for a rebuild.

 

It will run for quite a while like that
Glad you fished it out

 

If I recall correctly (vaguely familiar) is that there is a tag like that on the outside of the differential cover. I changed mine a year ago.
Again, just vaguely recall that so could be very wrong. But how it would end up INSIDE is beyond me except that at least the fluid had been changed before

 

There was two tags on the diff cover, but they were about 3/4 x 2 inch and very thin. This piece had a definite crack along one edge and peening around the radius. .065 inch thick. Looks like a clutch plate ear was torn off. Can't figure how that happened without other damage. Maybe it's telling me that it wants new gears...(4.10 would be nice, this is going to be my rock hound truck)