1965 Ford Mustang 4-Speed T-10 Transmission
unit. Shift forks in foreground, 1-2 fork on left, and 3-4 fork on
right. Main drive gear (a.k.a. "input shaft," driven by the engine
crankshaft when clutch is engaged) is on the right. On far left is the
case extension, showing linkage that goes ultimately to the stick
shift. When mounted on the car, coming out of the case extension would
be the driveshaft, with U-joint, connecting to the rear differential to
drive the rear wheels.
photo shows the tranny upside down to the way it is oriented when
bolted to the Mustang chassis. That is, when the transmission is
installed, the shift forks come out of the driver's side of the
Zoom in. Note the reverse shifter lever on the left. Just to the right of it you can see two spur gears. The larger spur
gear is the reverse gear. The smaller spur gear is the rear reverse idler gear.
in again. The lower set of gears is the mainshaft with, from left to
right, 1st gear, brass synchronizing ring, 1-2 clutch sleeve (clutch
hub underneath), brass synchronizing ring, 2nd gear, 3rd gear, brass
synchronizing ring, clutch sleeve (clutch hub underneath), brass
synchronizing ring, main drive gear (which doubles as "fourth gear",
a.k.a. "direct drive").
The upper set of gears is
the countershaft, a.k.a. the countergear or clustergear. Four gears are
mounted on the countershaft. The left-most countershaft gear (meshing
with 1st gear) is not visible in the photo, because the small, front
reverse idler gear hides it. Note that the front reverse idler gear
teeth slant in the same direction as the teeth on 1st gear. Therefore,
these two gears cannot mesh. It only seems like they mesh because the
photo does not capture all the detail. The front reverse idler gear
meshes with the left-most gear on the countershaft.