"Presuming it did actually break off of something in THIS gearbox/engine and isn't a foreign body that fell in at some point... Could be a piece of lock tab, I haven't used lock tabs for decades as the re-manufactured ones are no where near the quality of the originals, a different material, and thread lock compounds these days are excellent. It looks a bit like the 'ear' of the laygear thrust washers too."

I sent the picture to Keith Calver and the above was his repsonse.

Deb

Gee, I gave up mind expansion a long time ago. There wasn't enough room for it to be productive .

I've never seen a gear tooth pop a face off although I guess it could happen. What I have seen is whole gear teeth and chunks that are full width missing. The lay gear of my first MGA is still in my garage 40 years later with a couple of teeth gone. The edge of this piece and the adjacent surfaces still make it seem more like a tab to me or a washer chunk. Thinking of the crankshaft and connecting rods there isn't anything I can think of that looks similar. But hey, I could be wrong. I've been wrong before and fully expect to be so again soon.

It could be the hardened surface that broke off of a gear tooth.

 Guys, expand your thought process to the motor as well.

I promise to update everyone when it is taken apart.

I do have a high res version that could be examined more closely.

Locktab seems likely with the shape of the two pieces together...

Terry

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I didn't mean the shaving of wax (great idea BTW!) sticking out of the joint but the other scrapes and gouges. I have tried to brighten up your pix. Terry 3.jpg shows the convex side. Terry 2.jpg shows the concave side. which appears to have green paint in it. Or maybe just oil varnish. Looks like paint in Terry1.jpg.

The shavings I refer to are in Terry 4/jpg to the left of the wax and in the small piece in Terry 3.jpg. It is where metal appears to be scraped from the surface and left at the side of the scrape. Some of the other small nicks might be from a tool used to bend a locktab ear up.

Could it be the "ear" of a locktab?

The stuff that looks like a shaving is left over bee's wax from pushing the two pieces together to take the picture.

Terry

The picures Terry posted seem to show one convex side and one concave side (or a rim on 3 sides). A gear tooth would be symmetrical and be polished from wear on one side more than the other. Also, a gear tooth would be much harder and most lilely wouldn't show the scraping and gouging on the convex side - it appears that there are 'shavings' still attached. If a gear tooth got into other gear teeth, they'd probably snap off too and wouldn't scrape or goughe that way. It looks like metal softer than gear teeth to me. I'm leaning toward something like a locktab tip.

Terry: Might the concave side fit a flat of a transmission bolt head?

A gear tooth is what was suggested by someone who has alot of experience.

The shape is certainly similar, but would a gear tooth appear be finished on both sides?

I do not have a transmission apart at this time to look and I need to drive this one a bit longer.

Craig: when it comes time for removal and dismantling I will let you know.

Terry

Sure that's not a gear tooth?

That is a strange one.  There aren't many things in the bottom end of the engine or in the gears that are steel and .030 to .080 inches thick that are not a washer or locktab.  The shift forks should be bronze; I remember seeing some MG aftermarket forks made of a "soft" steel, but I'm not familiar with anything like that for a Mini.

I'm stumped, let's take it apart !!!!

"Fork" is bronze or brass

That would go along with the recent shifting clicks I am hearing.

At the end of a track day last month I was getting an occasional click into third that I attributed to an old tired guy at the end of the day with a slow foot or hand not synchronized together.

Terry

could it be the tip off the syncro fork?

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Craig you are correct, they fit together. I took some bees wax from my old photo kit and they fit nicely together.

I had not tried to mate them together. I would say they are close to the thickness of the dime

Am I right in thinking that the broken ends of the two pieces fit together?  Also, how thick are they?  They look to be thicker than the dime in the photos.

I have a magnet on a spring-like thing which I pushed in, nothing of any size came out with it.

I was not real aggressive with pushing it in though.

Terry

could be from the motor as well.

I would get a longer magnet and see what else I could get out

only 2 pieces?

4 synchro rod change, I have noticed a slight click when shifting into second before going into first at a stop light.

Old habit that is still with me.