Buick 10029787 Camshaft

To begin, remove the engine from the car, followed by the rocker arm covers, pushrods, and valve lifters. Next, take off the crankshaft front cover, fuel pump, and fuel pump pushrod, then remove the distributor. After that, detach the timing chain and camshaft sprocket. Install two bolts into the camshaft bolt holes to use as grips for pulling the camshaft out of the engine block, ensuring to do this slowly to prevent damage to the camshaft bearings as the journals pass through the bearing surfaces, while supporting the camshaft with one hand near the engine block. Before installing the camshaft, coat each of the lobes and journals liberally with lithium-based grease, then slide the camshaft into the engine block, taking care not to damage the bearings. Install the camshaft sprocket and timing chain, ensuring that the marks on the crankshaft and camshaft sprockets align, and confirm that the number 1 piston is at top dead center using a dial indicator. Finally, reinstall the remaining components in the reverse order of removal.

It is assumed that the engine is already out of the vehicle and the rocker arm cover has been removed, as this procedure cannot be performed with the engine installed. Once lobe lift has been determined, the pushrods, pushrod cover, valve lifters, distributor, oil pump driveshaft, front pulley and hub, and timing gear cover must be removed before the camshaft can be extracted. Camshaft lobe lift is a critical inspection procedure that should be conducted before removing the head from the engine. Lobe lift is typically measured by placing a dial indicator atop the cylinder head next to each pushrod and measuring the rocker arm's movement as it is pushed upward by the pushrod and cam lobe. Starting with the number one cylinder, mount a dial indicator with the stem resting on the rocker arm, aligned with the exhaust valve pushrod. Rotate the crankshaft slowly in the normal running direction until the lifter stem is on the heel of the cam lobe, at which point the pushrod will be at its lowest position. Zero the dial indicator, then slowly rotate the crankshaft until the pushrod reaches its highest position, noting and recording the reading on the dial indicator for comparison with lobe lift specifications. Repeat this for each remaining valve, and if the measurements do not meet specifications, a new camshaft should be installed. For a four-cylinder engine, remove the camshaft thrust plate screws/bolts by rotating the camshaft until the access holes in the timing gear align with them, then extract the camshaft and timing gear through the front of the block, taking care to avoid damaging the camshaft bearings. If the timing gear needs to be removed from the camshaft, it must be pressed off using a hydraulic press; if unavailable, take it to an automotive machine shop. Before installing the camshaft, coat each of the lobes and journals with engine assembly lube or moly-base grease, then slide the camshaft into the engine block, ensuring not to damage the bearings and aligning the marks on the gears. For a V8 engine, after removing the valve lifters, crankcase front cover, timing chain, and timing sprocket, detach the camshaft rear cover and use a long bolt in one of the camshaft bolt holes for support during removal. Carefully pull the camshaft out of the engine block, ensuring not to damage the camshaft bearings, and before installation, coat the lobes and journals with engine assembly lube or moly-base grease, sliding the camshaft into the engine block while supporting it with wire to prevent bearing damage.

After bearing replacement, lubricate the camshaft, align the timing marks, and reinstall it, along with the distributor. Reinstall the remaining components in reverse order.

Reject any camshaft that does not meet specified limits.

Slide the camshaft into the engine block, taking care not to damage the bearings, and position the camshaft and crankshaft gears so that the valve timing marks align, indicating the engine is in the number 4 cylinder firing position. Install the camshaft thrust plate mounting screws and torque to specifications, then complete the installation by reversing the removal procedure, ensuring to rotate the engine 360° to the number 1 cylinder firing position when installing the distributor.

Reinstall the remaining components in reverse order of removal.

After completing the checks, compare the results to the specifications; if the lobe lift is below the specified value, it indicates wear and necessitates a new camshaft.

After cleaning the camshaft, inspect the bearing journals for wear or damage; if damaged, both the camshaft and bearings need replacement. Measure the bearing journals for size and roundness, checking clearance against specifications.

Coat each of the lobes and journals with camshaft assembly lube.

Clean the camshaft with solvent and dry it.

Reverse the removal procedure to complete the installation and recharge the air-conditioning system if applicable.

Shallow surface scratches can be removed by rubbing with a fine emery cloth or an oilstone.

Ensure the timing marks on the sprockets are aligned before removal to prevent damage to the camshaft journals.

If the engine has been removed from the car, disregard the following steps which do not apply.

If the measurements are not within 0.002-inch of the specified lobe lift, a new camshaft should be installed.