i mean, listen at idle and push the clutch in and see if it goes away. it shouldnt make any noise while driving.

I had the exact same noise as Brainy after putting in an ACT XT. I do recall greasing all the recommended points. My 5 speed blew up over 20k miles later, most likely due to 240whp.

This.

4th gear is straight through input to output 1:1 and dosn’t load bearings. everything sends torque through a secondary shaft and loads bearings.

Mine would squeal at light load after a flog session, usually coming off the track or at the end of an autocross run. After a little while a big bang would leave it with no drive in any gear but 4th. I have also broken second gear and 3rd gear only in other transmissions and when that happens it didn’t squeal prior to failure. I’ve broken 7 of them with 3 different failure modes. I havent thoroughly investigated but I think the squeal could possibly be from a chiped gear tooth getting stuck in a bearing and the race spinning.

Bob

Mine makes noise in neutral AND while moving, but not with the clutch in and the car stationary. I will see if I can get a video of it tomorrow or something.

Mine does this. Held longer than my engine at my power level...

Is it more of a whine or does it sound like a "big ass cricket"?

https://www.miataturbo.net/general-miata-chat-9/clutch-squeaks-after-long-drive-45805/

Less noise than a freight train and more noise than a sleeping kitten?

I thought that 5 speeds were so cheap that you were supposed to swap it out each time you miss a shift?