Found a ball bearing on my magnetic drain plug!
 

I changed the oil in my gearbox tonight (GT86 2014 M/T) , and among the fine metal paste on the drain plug magnet was a 5mm ball bearing! :eyebulge:

Anyone have any suggestions as to where this could have come from?

Gearbox has been working fine. I had a mechanic change the gearbox and diff oil at least 2 years ago as I was to lazy to do it myself. I don't know what oil they used, I think the shift was noticeably better prior to the oil change.
I put penrite in it tonight and it seems to shift well.

I've never seen inside one of these gearboxes but I don't imagine there's many places a ball bearing could fall out of and not cause serious problems...

I did see on the bottom of my crappy chinese pump that it uses bearings for check valves, maybe ball came out of the last guys pump? I don't know :iono:

Shift detent ball.

Each synchronizer hub has three of these balls (and springs) between the hub and sleeve. It's not uncommon to have one or two pop out, and get away with the remaining ones. If shifting isn't horrible (and maybe more importantly, it's not slipping out of gear on its own), it's something you can forget about.

https://www.ft86club.com/forums/showthread.php?t=139737

Man, it's crazy that somehow its possible for that to happen. And equally crazy it makes no difference to the operation of the gearbox! I might look into finding another box and getting it rebuilt in case of failure.

I believe one of the mods Jacks Transmissions does to these is to prevent this from happening. It is from shifter overtravel from what I understand.

Glad that someone was able to offer information quickly on this one, that would have had me freaked out as well.

Do our gearboxes have a magnetic drainplug from the factory?

My Jacks broke, allowed one of these balls out, and the transmission ended up completely jammed in third gear.

I guess in some order the ball can pop out, the hub breaks next to the synchro ring tab, you get some overtravel of the shift fork ring whatever it is called, the synchro can rotate, and it can all get kind of stuck in a position where the shift fork ring won't move due to alignment of everything.