5k Drain and Fill Rear Diff, Look What I Found...

Yes. Not uncommon to have these little spirals left over as a byproduct from the machining of the housing or even the tapping of the magnetic plug itself during fabrication of the diff. Seen it on cars and trucks for decades.

OP:

There's a good reason that modern differentials have magnetic plugs in them (didn't see them as much in older cars and trucks). That plug will collect small metal fines and other small metallic bits during the life of your truck and keep them out the gears mesh and bearings...and this process is completely normal. An example of this is "gear fuzz" (see photo below). It is normal for the gears to shed metallic fines during the break in process. Again, this process willl abate as time goes on.


Additionally, it is not uncommon if you see metal shavings left over from the machining of the housing (see pic below). These types of shavings do not adversely affect the operation of the axle. As with gear fuzz, these should go away after the first fluid change.




What you don't want to see are bearing, tooth or even large washer fragments on the plug.

At least once a month, we see these threads on the forum. On the first and second gen forums, it usually garners a little more concern because these are observations made after tens of thousands of miles or even hundreds of thousands of miles on diffs that had previously shown no particles or fragments on the plugs.

However in the third gen forum, people often get concerned over these magnet findings and the responses they get range from "normal - but keep and eye on it" to alarmist. I would not be alarmed. That little spiral shaving is not uncommon, its not abnormal and my bet is that you won't see another one.

 

I wouldn’t worry about it. I found them in my 2nd gen dif change. Found in here that it appeared to be milling flakes from the manufacturer. And I waited till 100k for the dif change.

 

Appreciate the constructive replies. I wasn't worried per se, but I did learn something about the milling process which is interesting (thank you). I'm one of those anal people that like to get out the factory fills quickly after the metal has broken in. Im at 5k miles and already did the oil twice.