GM 12648846 Lifter Assembly, Valve

To determine the extent of cam lobe wear, position the number one piston at TDC on the compression stroke, remove the valve cover, and loosen the rocker arm nuts to access the pushrods. Then, mount a dial indicator on the engine, position the plunger against the top of the first pushrod, and zero the dial indicator. Slowly turn the crankshaft in the normal direction of rotation until the indicator needle stops and moves in the opposite direction, indicating maximum cam lobe lift. Record this figure and repeat the check for each valve.

After installing the camshaft, you should: 1. Refill the cooling system. 2. Change the engine oil and filter. 3. Start the engine and check for leaks.

To determine the extent of cam lobe wear, position the number one piston at TDC on the compression stroke, remove the valve cover, and loosen the rocker arm nuts to access the pushrods. Then, mount a dial indicator on the engine, position the plunger against the top of the first pushrod, and zero the dial indicator. Slowly turn the crankshaft in the normal direction of rotation until the indicator needle stops and moves in the opposite direction, indicating maximum cam lobe lift. Record this figure and repeat the check for each valve.

During inspection of the camshaft, you should: 1. Clean the lifter and camshaft with solvent. 2. Check for wear and damage on the lifter and camshaft. 3. Measure the journals and cam lobes for wear. 4. Replace the camshaft and bearings if they are damaged.

After removing the camshaft, you should clean and inspect the bearing journals for damage. Measure the bearing journals and camshaft lobes. Check the lobes for discoloration, score marks, chipped areas, pitting, and uneven wear.

The measurement for cam lobe lift should be taken by slowly turning the engine until the pushrod is at its lowest point (base circle of the camshaft lobe), then zeroing the dial indicator. The crankshaft is then rotated in the normal direction until the indicator needle reaches its peak and begins moving in the opposite direction, marking maximum cam lobe lift. This measurement is important to assess camshaft wear.

After installing the camshaft, you should:1. Refill the cooling system.2. Change the engine oil and filter.3. Start the engine and check for leaks.

After installing the camshaft, you should:1. Refill the cooling system.2. Change the engine oil and filter.3. Start the engine and check for leaks.

The steps for installing the camshaft are as follows:1. Lubricate the camshaft bearing journals and cam lobes with assembly lube.2. Slide the camshaft into the engine.3. Install the camshaft thrust plate.4. Install the balance shaft drive gear.5. Install the timing chain and sprockets.6. Lubricate the lifters with clean engine oil.7. Install the lifters in the block.8. Complete the installation in reverse order of removal.

After installing the camshaft, the cooling system should be refilled, the oil should be changed, and a new oil filter should be installed before starting and running the engine.

There is 1 lifter per order