1942 - 1947 Chevrolet Shop Manual



	4-20

	When installing new bearing outer races, use special driver J-1322 for front race, and J-1321 for rear race—care should be exercised to press the races squarely and firmly against their seats. NOTE—The pinion cage as serviced through the Parts Warehouse will come with the front and rear pinion bearing outer races pressed into place. The double reduction shaft left bearing cap will be serviced with the outer race in place, because it requires expensive tools to remove and replace the bearing outer race. The ring gear and pinion will be serviced only in matched sets. Reassembly Lubricate the bearing roller races. Install the rear pinion bearing on the drive pinion, install spacer on shaft up against bearing. Install pinion, bearing and spacer in the pinion cage. Then install over the pinion shaft, and up against the front face of the spacer inside the cage, the same number and thickness shims as removed. Press the front pinion bearing on the shaft until stopped; this should produce a slight "drag" when turning the pinion cage. Should the cage turn too freely, or too hard, remove the front bearing and add or remove shims as necessary to produce the slight "drag," or proper adjustment. Shims are available in .021", .024", .030" and .034". After arriving at proper adjustment of pinion bearings, install spring-loaded oil seal, with open end of leather to the rear, using a driver to support front face of seal to prevent damage. Install joint yoke, washer, nut and cotter pin. Double Reduction Shaft—Disassembly Remove the lock rings from the bearing nuts. The nut at the end opposite the ring gear should be removed first, to permit removal of the bearing, low-speed pinion, shifter sleeve, and detent balls and springs. Then clamp the splined section of the double reduction shaft in a vise equipped with copper jaws to protect the teeth, and remove the bearing nut from the ring gear end of the shaft. Replace the shifter sleeve on the shaft, allowing it to bear against the high-speed pinion. With the assembly resting on the shifter sleeve supported in an arbor press, press the bearing and ring gear from the shaft. Fig. 38. Inspection Clean all parts and inspect the ring gear and double reduction pinions for cracked or chipped teeth. Check the fit of the pinions on the shaft and inspect the bearings for damaged rollers or cracked races. Any damaged parts should be replaced. Fig. 39 shows the parts which make up the double reduction shaft assembly.	Reassembly Before installing the double reduction pinions on the shaft, their inner bearing surfaces must be thoroughly lubricated with rear axle lubricant for initial lubrication.

		Fig. 38—Removing Double Reduction Shaft Bearing on Ring Gear End Install the high-speed double reduction pinion on the shaft with the spur gear side toward the spur gear on the shaft. Start the ring gear on the splines. Then press the ring gear on the shaft. During this operation use a feeler gauge to check the clearance between the high speed double reduction pinion and the splines on the shaft; a clearance of .015" to .020" (.015" or near this preferred) must be allowed between these two parts to prevent scoring and to allow proper shifter sleeve travel. Fig. 40. This clearance is controlled by how far the ring gear is pressed on the shaft.

		Fig 39—Layout of Double Reduction Shaft Assembly Start the roller bearing on the shaft, and, using a sleeve over the shaft and against the bearing inner race, press the bearing solidly against the ring gear.