Transfer case 5 mm ball bearing

I'm getting a humming noise in the rear end somewhere. sounds like a wheel bearing that went bad on my 97 camry a few years back.(I think it was the camry. anyways one of my cars)

I drained my transfer case this morning. Looks like it was never changed in 192,000 on my 94 all trac. It is dark and thick with slimy chunks throughout the oil.

When i removed the drain plug there was a 4.5 mm ball bearing stuck to the plugs magnet.

Any Ideas? can this be fixed ?

Is this where my noise is coming from? The rear diff was completely empty due to the oil seal leaking and now filled with new oil and still have the noise.

Pete

Realize this is a crazy old thread but recently had this happen to me when changing fluid. Mine is not making noise and fluid had lost viscosity but wasn't burnt. Anyone heard or seen this before.

The ball bearing is probably the one which should sit inside a hole in the shift fork and interfaces with two detents on the shift shaft. I just looked inside my spare transfer case just now. If it is this ball, the only way it can come out is if the shift fork is disassembled from the fork shaft (or if the shift fork has snapped off!). There is a note I wrote in my repair manual on one of the disassembly steps ... "ball and spring will pop out". Do you know the vehicle's history? If it is indeed this ball which has somehow become misplaced it may allow the ring gear upon which the shift fork acts to locate abnormally and wear the gears, but checking all this out is a fairly major task.
There is one thing you could do which is simple and would at least provide some information. On the rear side of the case is a cap nut with an elongated head which is the cap for one end of the fork shaft. If you remove this the end of the fork shaft will be exposed. The cap is well above the oil level so no risk of mess. The shaft should stick out 15mm from the case for the normal driving mode. If it is flush with the case you know it has been modified to be in the permanent lock mode and then you know it has been messed with and the question would be why?