Internal Gear Shift

Internally, the gear shift mechanism begins with the input shift shaft, which is connected to the external linkage.

Attached to the input shift shaft is the shift shaft selector arm. The selector arm and its associated selector plate act together to transmit the inward, outward and rotational movements of the input shift shaft to the internal shift lever. The shift lever in turn, transmits these motions to the main shift control shaft, to which the 1st/2nd and 3rd/4th shift forks are attached.

The 5th shift relay lever is connected to a main shift control shaft member and transmits motion to the 5th gear control shaft, to which the 5th shift fork is attached. Movement in one direction actuates 5th gear. In the other direction the reverse shift relay lever is actuated, engaging the reverse idler gear with the input cluster and main shaft reverse sliding gear.

An interlock is provided on the main shift control shaft. The interlock allows the shifting of only one synchronizer at a time. This prevents the engagement of the transaxle in two gears at the same time.

The reverse idler gear is shifted into position when a pin on the 5th gear control shaft engages the reverse relay lever. The pin moves the reverse relay lever which moves the gear on the reverse idler shaft into engagement with the input cluster shaft and main shaft reverse sliding gear.

The backup lamp switch is actuated by movement of the 5th gear control shaft.