[Dam]

Yesterday i wanted to change the oil on my differential (non LSD). I have a 72 GT 1300 Junior. When i drained the oil on the magnetic plug i found a little piece of metal. I attache some photos. What could it be? Do i have to worry? Thanks.

 

[Alfar7]

If it`s not making a noise don`t worry about it.

 

[0die]

that is a very sizable chunk. Looks to be the edge of a seal, the metal housing part that holds the rubber seal. Was that all that was on the magnet?

Usually there will be a little fine metal powder on the plug, from break in wear...Often you might be the first person to ever change the gear oil so you will find 50 years of metal shaving from the break in process. Many owners of all kind of cars never check the rear end or only top off the fluid, never draining it.

If your oil was clean other than the big chip...meaning no fuzzy metal on the magnet...then that oil has been changed a few times already in it's life. It's entirely possible the pinion or an axle seal was replaced at some time. Perhaps the old seal got broken up on removal and a chip from it got left inside and worked it's way to the magnet and got captured.

Fresh fill of gear oil and drive on.

 

[Alfajay]

Looks to be the edge of a seal, the metal housing part that holds the rubber seal.

I agree with the comments that suggest "if it ain't broke, don't worry about it". And in this case "broke" means "making noise".

Still, it's puzzling where that piece came from. Odie's idea is good - does the piece look more like sheet metal (which the seal housing would be) or part of a solid casting/forging (as a gear tooth would be)? If it's a gear tooth, you might worry a little, but the "if it ain't broke" maxim still applies.

 

[GTA Alfa]

If your going to change the diff oil, it wouldn't be a bad idea to drop the small pan just to ensure there is nothing else sitting in the gooey oil which maybe hasn't made its way to the magnet yet.

 

[PSk]

If it`s not making a noise don`t worry about it.

This.

It looks like a piece of the pinion to me (on second look I'm probably wrong), and if it is the pinion is already ruined beyond repair so pulling it apart now will not save the pinion or crownwheel. What I would recommend doing is locating another axle of the right ratio that you can build up with new bearings to swap over when this one fails ... which might be 10 years time (things always last longer when you have a spare ready).

But if not leaking oil or making a noise, I agree with Alfa7
Pete

 

[racingswim2006]

Looks like a portion of the pinion shim.

 

[goats]

part of a bearing race / cage is my guess. I too would probably leave it alone unless you are ambitious enough to remove the diff/open it up / replace it. Its not a hard garage job, done it a few times one-man-band style with a floor jack, probably an hour to remove , 3 to open it up/scope it out / reseal it/ replace pinion seal, and another hour or two to replace it back in -pro tip -- remember when you put it back in place, the sway bar downarms go BEHIND the axle! You could also remove the cover in-situ (I;ve heard it done, never done myself).

 

[Dam]

Thanks to all for the reply. The magnet doesn't had much fuzzy metal, almost compared to the gearbox. I don't think that it's a tooth piece, because the metal object present a similar wear on the two side and the two side are equally smooth. So perhaps it is more likely to be a pinion shim? As someone already said? Thanks.