Help ID'ing a Part

[twiget]

I'm finishing up a gear change on the rear end of my 'burban. It is a 14 bolt 10.5" rear end. I got everything adjusted, and was doing one last check to make sure everything was working well, when I noticed this on the bottom of the housing:

(quarter for size reference)

Until I found this thing, I was 100% sure that I had put everything back together correctly. Now I'm ~98% sure. It is magnetic, and it was at the bottom of the housing, which leads me to believe that its purpose in life is to suck up any metal shavings as the gears wear in. The only thing holding it in place was the force of the magnet though, which kind of disturbs me. If that thing came free, that would be the end of my new gears...

Any thoughts?

 

[nvrenuf]

...its purpose in life is to suck up any metal shavings as the gears wear in. The only thing holding it in place was the force of the magnet though, which kind of disturbs me. If that thing came free, that would be the end of my new gears...

Any thoughts?

You're correct, it's just a magnet to catch junk. It's ok to let it stick to the housing with it's own power but it your really worried about it put some epoxy on it. The drawback with that is the center hole will difficult to clean out because you can't remove it.

 

[twiget]

I decided to leave it in there. It is entirely possible that this was the first time the diff was opened since the truck was originally assembled. At the very least, the previous owner and I have put 5,000+ miles on it (he did not drive it very much) with the magnet in there, and nothing happened.

As a side note, the installation instructions that came with the new gears said to change the gear oil after 500 miles. I'm not questioning the wisdom of that. What I am curious about is why that is not recommended when a new car is purchased. Do OEM's do something special, so that an oil change is not needed after a 500 mile break-in?

 

[4X4HIGH]

It is always a good idea to change any oil after a rebuild be it an engine, trans or diff. There are impurites that will be removed when doing the oil change.

Why a new vehicle doesn't suggest it is beyond me but even if it was suggested how many people do you think would actually do it?

 

[manchildau65]

I agree completely with 4X4High, you'll be surprised how much break-in will occur with a new set of gears (especially with a 10.5" ring gear).

My new Dodge (I know it's a Dodge but I wanted the Cummins) required the diff. fluid changed after the first 20K miles.