How to Remove the Rear Main Seal in a Chevy S10by Gus Stephens
The rear main oil seal in a 2.2 liter Chevrolet S10 can be replaced without removing the engine oil pan or the crankshaft. However, removal of significant components external to the engine, most notably the transmission, is required. Once you've performed these heavy-duty tasks, replacing the seal itself is a straightforward procedure. Symptoms of a leaky rear main oil seal include noticeable seepage of oil from the rear portion of the engine. In vehicles with a manual transmission, clutch slippage or "chattering" may also result if leaking oil contaminates the facings of the clutch disk.
Removing The Old Seal
Remove the transmission. On vehicles with a manual transmission, remove the clutch pressure plate and clutch disk. For automatic transmissions, remove the torque converter. Remove the flywheel (manual transmission) or the drive plate (automatic transmission.)
Carefully pry the rear oil seal out its bore in the exposed end of the engine block using the seal removal tool or a large screwdriver. The seal fits snugly around the crankshaft; take care not to scratch or nick the polished surface of the crankshaft. If the crankshaft is scratched, the entire crankshaft must be replaced or new leaks will develop.
Clean the bore in the engine block which accommodates the seal. Carefully clean the surface of the crankshaft where the lip of the new seal will make contact.
Install The New Seal
Coat the lip and the outer shell of the new seal with clean engine oil.
Guide the new seal over the end of the crankshaft and press into the engine block bore using the GM seal press tool. If this tool is unavailable press the seal in place by gently tapping around its outer edge with the small block of wood and a hammer until the seal is fully inserted. Make sure it's square in the engine block bore and the outer edge of the seal is flush.
Reinstall the flywheel or drive plate. For manual transmissions, align the clutch disk with the clutch pressure plate and install on the flywheel; for automatics, bolt the torque converter in place on the drive plate. Reinstall the transmission.
- "Haynes Chevrolet S10 And GMC Sonoma Pickups 1994 Thru 1998 Repair Manual"; Robert Maddox; 1996,1999
- Clutch disks have a limited life span. Since you've got the transmission out to replace the rear main seal anyway, do yourself a favor and take this opportunity to replace the clutch disk at the same time.
Things You'll Need
- Socket wrench, sockets and extensions
- Torque wrench
- Seal removal tool or large screwdriver
- Seal press tool (GM part 34924) or a small blunt block of wood.
- Replacement rear oil seal
- Clean Engine oil
Gus Stephens has written about aviation, automotive and home technology for 15 years. His articles have appeared in major print outlets such as "Popular Mechanics" and "Invention & Technology." Along the way, Gus earned a Bachelor of Arts in communications. If it flies, drives or just sits on your desk and blinks, he's probably fixed it.