The G15M-R manual transaxle is a fully synchronized five-speed transaxle. The forward gears are selected by a synchronizer mechanism. Third gear (3GR), fourth gear (4GR) and the fifth speed cluster gear are mounted on the input shaft. First gear (1GR), second gear (2GR) and the reverse output gear are mounted on the output shaft. The helical-cut forward gears are in constant mesh with the corresponding gears on the opposing shaft. The G15M-R features a synchronized reverse gear. The reverse gears have straight-cut teeth and are engaged through the reverse idler gear and bushing.
External Shift Linkage
The G15M-R manual transaxle is controlled by a floor-mounted gearshift lever located in the console panel. The gearshift lever is attached to the transaxle case through the gearshift lever stabilizer bar and support. Gearshift lever movements are transferred through the transmission gearshift rod and clevis.
Internal Shift Linkage
The G15M-R manual transaxle is shifted internally by three shift forks. The fifth and reverse gear shifter fork shifts in and out of the fifth and reverse gears. The first/second and the third/fourth shift forks control all other forward gear shifts.
The reverse idler gear and bushing is mounted on a reverse idler gear shaft supported at one end in the flywheel housing and at the other in the transaxle case. Because the reverse idler gear and bushing slides and rotates on the reverse idler gear shaft, the bushing is necessary to prevent metal-to-metal contact and wear.
When the reverse idler gear and bushing slides on the reverse idler gear shaft, it engages the reverse drive gear on the input shaft and the reverse gear on the output shaft. The driving gear is part of the input shaft and the reverse gear is machined on the outside diameter of the first/second synchronizer sleeve.
When the reverse idler gear and bushing rotates on the reverse idler gear shaft, it reverses the power flow to the output shaft.
To engage the reverse idler gear and bushing, the motion of the shift fork selector lever is transferred to the reverse gearshift lever through the shift gate. The reverse gearshift lever is mounted on a meshlock plunger that allows it to act as a fulcrum. When the fifth/reverse gearshift selector arm moves its end of the shift fork selector lever, the opposite end slides the reverse idler gear and bushing into engagement with the input shaft and output shaft reverse gears.
The G15M-R uses a reverse blocking ring mounted to the input shaft above the fifth speed gear. When the transaxle is engaged in reverse, the fifth gear synchronizer hub is pressed against the reverse blocking ring, which is pressed against the reverse blocking ring retainer. This retainer is connected to the input shaft. As the blocking ring cone surface engages the cone surface of the retainer, it stops rotation of the input shaft and allows the smooth meshing of the reverse idler and the reverse speed gear.
The ends of the differential are supported on tapered roller differential bearings. The cups for these differential bearings are seated in the transaxle case and the flywheel housing. Preload on the differential bearings is set using a selective differential bearing shim that is installed under the differential bearing cup in the transaxle case.
The differential includes the differential side gears and the shaft mounted differential pinion gears. Direct contact between the four gears and the differential case is prevented by the differential side gear thrust washers installed under the gears. The differential pinion shaft is held in position by a differential pinion shaft lock pin that extends through the end of the differential pinion shaft and the differential case.
The speedometer drive gear is also mounted on the differential case. It is located between the tapered roller differential bearing and the differential case. A tab on the speedometer drive gear and a matching slot in the differential case prevent the speedometer drive gear from spinning on the differential case.