GM 12521221 Cover Assembly, Crankcase Front End

To be able to remove or install Buick engines, just follow these, Drain cooling system and pull out the radiator, fan, pulley and belt. Remove fuel pump and the alternator if necessary. Distributor should be removed but not before noting its position so that it won't disturb anything. To achieve this, you need to remove the thermostat by-pass hose, harmonic balancer, timing chain-to-crankcase bolts and also oil pan-to-Timing Cover bolts in order to take off the Timing Cover. After driving out the old seal and shedder, coil new packing around opening, drive in shedder, and properly size packing. To make sure of this camshaft sprocket bolt shall be removed without changing its position while sprockets' timing marks coincide with each other and front crankshaft oil slinger is detached from it for good. On a 350 engine there is a crankshaft distributor drive gear and fuel pump eccentric while on a V6 there are camshaft sprocket bolts that must be removed. The camshaft may then be carefully pried along with crankshaft sprockets forward thereby removing all of them together with their chains. Then you need to check that No. 1 piston is at top dead center before assembling the timing chain on both sprockets and sliding them onto shafts with 0-marks aligned; thereupon put slinger into place on crankshaft; slide fuel pump eccentric on camshaft followed by putting woodruff key in place; put back distributor drive gear as well as eccentric bolt over there. Tighten bolts using specified torque values then install new seal gasket plus cover for timing case after which secure it using appropriate bolts. Before reinstalling oil pan plus other components clean all gasket mating surfaces as well as apply silicone sealer to oil pan-to-cylinder block joint. In Pontiac Engines (265 & 301), drain the cooling system, disconnect hoses, vacuum lines, and spark plug wires, and remove the radiator. To enable this happen is simply disconnecting the accelerator linkage and temperature gauge wire as well as fuel lines. Hood latch brace, PCV valve hose, rocker covers, distributor, intake manifold are to be completely removed together with valve cover. Just loosen rocker arm nuts and then remove pushrods plus lifters. After that take out the timing cover and gasket followed by fuel pump eccentric and bushing in order to get at harmonic balancer; fuel pump; oil pan-to-timing cover bolts; the harmonic balancer; oil pan-to-timing cover bolts; timing cover as well as gasket; timing chain along with sprockets replacing it later with new ones. First of all position the engine with No. 6 piston at top dead center even before rotating crankshaft to align camshaft gear mark at 12 o'clock after which slide these camshaft plus crankshaft sprockets onto their respective shafts having their 0-marks aligned. This should be done prior to putting slinger on crankshaft or installing fuel extractor eccentric or using camshaft sprocket bolts such as camshaft thrust plate. Lubricate parts during reassembly according to procedures employed earlier in disassembling them. In Chevrolet Engines (305 & 350), drain radiator and take off belts including fan, pulley, crankshaft pulley and balancer among others. Clean all gasket mounting surfaces first of all. In reinstalling process apply silicone sealer for oil pan-to-cylinder block joint; use a centering tool when handling front cover then tighten it down by securing its bolts; hang harmonic balancer on place like it was before then put back pulley too just like it is supposed to be followed by water pump that needs some new belts which must also be fixed on place along with other parts such as radiator and the like. For Oldsmobile Engines (307, 350 & 403), drain the coolant, disconnect hoses, remove fan, belts, pulley, crankshaft pulley and balancer on some models. Remove front cover bolts then take it off along with timing indicator and water pump. Later models have dowel pins that are ground while their ends are chamfered. Just trim gaskets before cleaning mating surfaces to apply sealer in addition to placing new seals as well as gaskets where they belong. After installing the cover again use another bolt to secure it; this is followed by tightening while holding down pan seal afterwhich press down on the cover and rotate it for a while; finally tighten bolts again. Lubricate balancer seal surface followed by reversing sequence of removal in which balancer is installed together with other parts.

You should also disconnect the coolant hoses from the fill pipe and water pump, unbolt the spark plug wire shield at the water pump, and disconnect the canister purge hose and tie it aside.

The old gasket material should be removed using a scraper and degreaser.

Tighten all bolts to the proper torque specifications and reinstall all components in reverse order, applying lubricant to the front hub seal before installing the crankshaft hub.

Detach the bolts that secure the timing chain cover to the cylinder block and the two bolts connecting the oil pan to the timing chain cover.

Use a gasket scraper to eliminate all traces of old gasket material and sealant from the cover and engine block, taking care not to damage the aluminum cover.

Remove the crankshaft pulley and hub if equipped, then take off the oil pan.

Start by removing the spark plug wire cover for the front cover only. For models from 1996 and later, take out the ignition coils and the coil mounting bracket to reach the rear cover.

After removing the crankshaft pulley, detach the timing gear cover by removing the bolts and cleaning the sealing surfaces with a scraper and degreaser.

Take out the rear engine mount nut and loosen the front engine mount nut, leaving about three threads in contact.

For manual transmission cars, also remove the front exhaust air pipe check valve.

Unbolt the spark plug wire shield at the water pump and disconnect the canister purge hose, tying it aside.