1942 - 1947 Chevrolet Shop Manual



	4-18

	On the double reduction shaft are the two double reduction pinions, each of which has an integral spur pinion on its inner side. Between them are two sets of short splines integral with the shaft, and a floating shifter sleeve that is moved by a shifter mechanism to lock one set of splines on the double reduction shaft with the spur pinion on one or the other double reduction pinions. The control is operated by a lever in the cab and connected to the shifter lever on the axle by cable and rod linkage. As the shifter lever in the cab is moved to the forward position, the shifter sleeve is moved to the right, locking the double reduction high-speed pinion to the double reduction shaft, at the same time disengaging the double reduction low-speed pinion, permitting it to turn freely on the shaft. The power from the engine is then transmitted through the propeller shaft, pinion and ring gear, then to the double reduction shaft and high-speed pinion. Thence to the high-speed double reduction gear through the differential to the rear axle and wheels, Fig. 33.	screws alternately, the axle shafts and aluminum gaskets can be removed from the wheel hub, Fig. 34. Remove the capscrews which fasten the differential carrier to the axle housing and place a jack under the carrier. The assembly can now be removed from under the truck.


		Fig. 34—Axle Shaft Removal Differential and Carrier Disassembly Place the assembly in a bench vise by clamping on the lower rib of the carrier. Remove the cotter pin, nut and washer from the end of the pinion shaft. The universal joint yoke may then be removed from the shaft. Before removing the differential assembly from the carrier, mark the differential bearing caps and adjusting nuts with a center punch for position identification when reassembling. This is important because the caps are machined in place. Remove the tie wire, differential bearing adjusting nut locks and the bolts from the bearing caps. Remove the bearing caps and differential assembly from the carrier. To remove the pinion cage and bearing assembly, remove the nuts which retain the cage to the carrier. NOTE—There are two tapped holes in the flange of the cage for use when removing a tight cage. It Is most important when removing the pinion cage and the double reduction shaft bearing caps that that number and thickness of the shims be checked for reference when reassembling. This will save considerable time when making adjustments.
	Fig. 33—Two-Speed Axle Operation [High Gear) When the shifter lever is moved backwards the shifter sleeve is moved to the left, disengaging the double reduction high-speed pinion and transferring the power through the low-speed pinion and low-speed gear to the rear axle and wheels. REPAIR OPERATIONS Wheel hubs, bearings, oil seals, and axle shafts are serviced in the same manner as on the conventional 1-1/2-ton truck rear axle. Removal of the Differential and Carrier Remove the two trunnion bearing "U" bolts from the rear yoke. Split the universal joint, shift the propeller shaft forward and allow the rear axle propeller shaft to drop down. Remove the capscrews and locks which retain the axle shaft flange to the wheel hub. Install two 7/16"-14 cap screws in the holes provided in the shaft flange and by turning the cap