Thanks for the compliment! I watched your video on the Bronco. Cool channel. When I was rebuilding my transaxle from my 1997 Eagle Talon, I got the idea to show how the synchros work. It was unscripted and I missed one major point, how the synchro sleeve pushes on the teeth of the syncro until the speed is matched and the shaft counter-rotates letting the gear engage. Anyway, if you bought those parts from the dealer, it would probably be as much as a junkyard transmission. Maybe ebay? I know lots of junkyards operate on ebay.

@2:31 The brass synchro ring and the sleeve always rotate at the same speed, but there is some play between the two parts. The sleeve bevel angle matches the bevel angle on the synchro ring so that the sleeve is what is pushing on the synchro until the input shaft speed matches the gear speed. Basically you're pressing the sleeve onto the synchro ring when pushing the stick into gear. The synchro ring in turn will press on the gear's cone and that friction changes the input shaft speed to match the gear speed. When the speed is matched, the input shaft bounces back and counter-rotates. The springs in the clutch disk help with this counter-rotation. The bounce-back allows the teeth to line up and mesh.

@@jtandrews3 thanks just as I thought, most animations showed the teeth lining up perfectly and I just couldn’t get my head around that

No. Some racing trans have large lugs that literally jam into other lugs. It is very aggressive and not really made for the street. They are usually called "dog boxes"

Yes, virtually every modern passenger (and definitely every USDM passenger vehicle) have synchronized forward gears, and a reverse gear, which is usually unsynchronized. Industrial machinery, like tractors and (most) semi trucks, and older buses, have unsynchronized transmissions, or crash boxes. Motorcycles (and most other sequential gearboxes) are almost always unsynchronized, but this is somewhat different in theory compared to an unsynchronized transmission. These are "constant mesh" transmissions with dog clutches in place of synchros, and thus don't require synchros for seamless shifts. Synchros wear though, and many drive with worn synchros. My 1st, 2nd, and 3rd synchros (and clutch) in my 09 Scion tC have been worn to the point that if I don't double clutch, I'll grind gears, or can't get into gear. In effect, it's a non-synchronous transmission with synchros.

@@callang9 many thanks