Chevrolet 91177421 Seal,Crankshaft Front Oil

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The seal contact surface should be carefully inspected for scratches and nicks that could damage the new seal lip and cause oil leaks.

The recommended method is to remove the oil pan and the seal retainer.

The old seal can be driven out from the back side with a punch and hammer.

To begin, if you need to replace the front crankshaft seal, you can usually do so without removing the timing chain cover by first removing the radiator for better access to the seal. However, if clearance is too tight, you may need to remove the cover, as explained below. For timing chain cover removal, disconnect the negative battery cable, drain the engine oil and coolant, and remove the oil pan. Note that in some cases, you may be able to remove the front cover without removing the oil pan, in which case only the front pan-to-cover bolts need to be removed. Remove the camshaft cover, the coolant bypass pipe, bypass hose, fan, cooling shroud, fan belt, and fan pulley. Also, remove the alternator belt, water pump pulley, alternator drivebelt tensioner, idler pulley, and disconnect the radiator outlet hose from the thermostat housing. Detach the air conditioning compressor from its bracket without disconnecting the refrigerant hoses, and remove the compressor mounting bracket. Use a pulley holding tool to remove the crankshaft pulley bolt and then the pulley itself. Remove the timing chain cover, ensuring you note the locations of the two dowel pins. For seal replacement, clean the timing chain cover thoroughly, inspect the front crankshaft seal for damage, and use a seal removal tool to pry out the old seal. To install the new seal, place the timing chain cover on a flat surface and tap the new seal into place with a large socket. When reinstalling the timing chain cover, apply RTV sealant to the mating surface and ensure the dowel pins are in place. Tighten the cover bolts and nut, then install the crankshaft pulley and bolt, tightening it with a pulley holding tool. Reinstall the air conditioning compressor bracket, alternator drivebelt idler pulley, radiator outlet hose, alternator drivebelt tensioner, water pump pulley, alternator drivebelt, fan pulley, fan belt, cooling shroud, and fan. Install the coolant bypass hose and pipe, camshaft cover, and oil pan. Adjust the cooling fan drivebelt tension, refill the cooling system with coolant, and add clean engine oil. Finally, start the engine and check for any coolant or oil leaks.

Remove the timing belt, crankshaft sprocket and inner belt guide. Wrap the tip of a small screwdriver with tape. Working from below, use the screwdriver to pry the seal out of its bore. Carefully pry the seal out with a small screwdriver-wrap the tip with tape to prevent damaging the seal bore and crankshaft sealing surface. Take care to prevent damaging the crankshaft and the seal bore. Thoroughly clean and inspect the seal bore and sealing surface on the crankshaft. Minor imperfections can be removed with emery cloth. If there is a groove worn in the crankshaft sealing surface (from contact with the seal), installing a new seal will probably not stop the leak. Try installing a repair sleeve which fits over the crankshaft sealing surface. These are normally available at larger auto parts stores. Lubricate the new seal with engine oil and drive the seal into place with a hammer and socket. Install the new seal by gently tapping it into place with a socket and a small hammer. Reinstall the timing belt and related components. Run the engine, checking for oil leaks.