1942 - 1947 Chevrolet Shop Manual



	*6-11*

	2. Place a new front camshaft bearing over the puller bar and start the bar through the front bearing bore. Place the puller sleeve with a new bearing over the bar before passing the bar through the other bearing bores in the cylinder block. Pass the end of the bar through the puller bracket and install the thrust bearing and turning handle. 3. Line up the oil holes in each bearing with the oil hole location marks previously made. All four bearings can now be pulled into place at the same time. 4. Remove the puller bar and bracket and stake each bearing into the hole provided in the bore for that purpose. Reaming Camshaft Bearings The special camshaft bearing line reamer has all four cutters mounted on one bar so that all bearings will be in perfect alignment after the reaming operation. 1. Pass the reamer through the first, second, and third bearings. Then start the reamer cutters into all four bearings and turn the reamer slowly until the cutters have passed through the bearings. While the bearings are being reamed, a liberal supply of kerosene should be used to wash out all metal cuttings. 2. Remove the reamer by pulling it back through the bearings, at the same time turning the reamer slowly in the same direction as when reaming the bearings. 3. Blow all cuttings from the bearings with compressed air. Install the camshaft and check all bearing clearances with a narrow feeler gauge. The proper clearance is from .002" to .004". Install the expansion plug in- the back end of the cylinder block at the rear camshaft bearing. CAMSHAFT The camshaft is designed to assure quiet operation, combined with accurate valve timing. The contour of each cam is carefully worked out to take up the valve clearance gradually, and all cams have a wear-resisting coating to insure long life. The valve lifters are located slightly off the center line of the cams. This design produces a spinning action to the lifter so the cams do not engage the same point on the lifters each time the valves open, resulting in long valve lifter life and quiet operation. The following is a list of the sizes of the camshaft bearing journals: front, 2.0282"-2.0292"; front intermediate, 1.9657"-1.9667'^/; rear intermediate, 1.9032"-1.9042"; rear 1.8407"-1.8417". Whenever a camshaft is removed from an engine it is important that these dimensions be checked with a micrometer for out-of-round. If	the journals exceed .001" out-of-round, the camshaft should be replaced. Another very important inspection operation, while the camshaft is out of the engine, is to check it for alignment. The best method is by use of "V" blocks and a dial indicator as shown in Fig. 17. The dial indicator will indicate the exact

		Fig. 17—Checking Camshaft Alignment amount the camshaft is out of true. If it is out more than .002" dial indicator reading, the camshaft should be straightened. When checking, the high reading of the dial indicator indicates the high point of the shaft. This point should be chalk marked to tell exactly where to apply pressure when straightening. NOTE—During the straightening operation care should be taken to protect the bearing journals to prevent damage to their surfaces. After the camshaft has been straightened, it should be re-checked to be sure it is within .002" dial indicator reading for alignment. CRANKCASE FRONT END PLATE This part is assembled to the cylinder block with from one to three gaskets. The reason for the varying number of gaskets is to provide the correct alignment for the timing gears.

		Fig. I8—Checking Timing Gear Alignment