53. DESCRIPTION.
a. Transmission has three speeds: low, second, and high, and is of the constant‐mesh, non‐selective type. High gear is direct drive. Since “dogs” on gear shifter clutches are used to engage transmission gears, it is of great importance that vehicle clutch is correctly adjusted. Clutch must be fully disengaged when shifting gears, to prevent clashing of gears, and possible damage to the shifter clutch “dogs” and transmission gears. It is also important that gear shifter control linkage be kept in correct adjustment to ensure full engagement of shifter clutch driving dogs in all positions, thus preventing possible damage caused by dogs jumping out of engagement under driving load. Close fitting and needle roller bearings, within the transmission, necessitate use of engine oil (seasonal grade) in transmission case for adequate lubrication.
54. CONTROL LINKAGE ([fig. 32]).
a. Transmission Shifted to Adjust Front Drive Chain. The transmission is located to receive power from front (engine) drive chain and transmit power through rear drive chain to rear wheel, and is movable on its mounting for adjustment of the front (engine) drive chain. When front (engine) drive chain is adjusted, transmission gear shifter control linkage is affected. Therefore, after each front drive chain adjustment, gear shifter control linkage must be checked, and, if necessary, correctly adjusted to ensure proper gear shifting with full engagement of the gear shifter clutch driving “dogs” as well as prevent transmission from jumping out of gear under load.
b. Checking Gear Shifter Control Linkage. Before making adjustment to gear shifter control linkage, make the following checks: See that all linkage points from transmission gear shifter lever to gear shifter hand lever are well oiled and free‐working. Check hand lever pivot bolt nut for tightness. Observe whether there is binding or interference with shifter rod at any point in the shifting range; this sometimes results from a bent snifter rod. Check whether or not shifter rod is correctly adjusted so that when hand lever is moved to any gear position in tank shifter guide, transmission lever moves to the proper position to fully engage shifter clutch dogs and shifter cam spring plunger in cam‐locating notch (inside transmission).
RA PD 310229
Figure 32—Adjusting Gear Shifter Rod
c. Adjusting Gear Shifter Control Linkage ([fig. 32]).
(1) Set hand lever in “N” (neutral) position in shifter guide.