How to Install a Ford 302 Rear Main Sealby Richard Rowe
The 302 (dubbed the 5.0 during the 1970s) is part of Ford's Windsor family of small block V-8s. Spanning nearly a half-century of continuous production, this family includes the 255, 260, 289 and 351. Ford produced millions of Windsor engines from 1962 to 2001, and all have some sort of rear main seal to seal the crankshaft against the engine block. Rear main seal leaks are common on both newer and older engines alike. While not especially expensive, installing a rear main seal is a time-consuming proposition that requires some experience to perform correctly.
Lift the front of the car with a floor jack and insert the jack stands. Unbolt the dust cover from the bottom of the transmission bell housing where the transmission attaches to the engine to expose the flywheel/flex plate and clutch/torque converter. If you have an automatic transmission, remove the three bolts that secure the torque converter to the flex plate.
Remove the car's radiator hoses, unbolt the radiator and remove it and the fan, if your car has an automatic transmission. Remove the throttle linkage from the throttle body. Connect your engine hoist chains to the lift hooks on either side of the intake manifold and apply slight upward pressure. Remove the two motor mount bolts on either side of the engine and lift the engine free. Remove the bell housing bolts that secure the engine to the transmission. Support the transmission oil pan with a cinder block and pull the engine upward and forward. Remove the bolts that secure the flex plate to the crankshaft and remove the flex plate.
Remove the transmission's shift lever dust boot and unbolt the shifter from the transmission housing, if your car has a manual transmission. Remove the transmission mount bolt under the crossmember. Remove the bolts that secure the transmission case to the transmission bell housing and pull the transmission out. Remove the bell housing bolts that secure the engine to the transmission and pull the bell housing off. Mark the clutch, flywheel and flywheel flange with a paint marker to ensure that you reinstall everything in the original orientation. Unbolt the clutch from the flywheel from the crankshaft and pull it off.
Remove the rear main seal from the engine block around the crankshaft. In some cases, the seal may just pull out with a pair of needle-nosed pliers or tap out using a flat head screwdriver and hammer. If not, try drilling three evenly-spaced, 1/8-inch holes onto the seal face and screwing in a couple of self-tapping screws. Turn each screw a half-turn clockwise and the seal will push itself out of the block.
Coat the inside circumference of the new seal with oil and push it into the block. Ford makes a tool to seat the rear main seal into the block, but you can use a small 2- by 4-inch block to do the same. After pushing the seal into the block as far as it will go, hold the block against it and tap the block with a hammer. Work your way around the seal to seat it against the engine block.
Reassemble everything in the reverse order of removal. As long as you put the flywheel and clutch on in the original orientation and didn't turn the splined transmission input shaft, the transmission should slip back into place the way it came out. Torque the flywheel/flex plate bolts to 85 foot-pounds, the torque converter/clutch pressure plate bolts to 40 foot-pounds, the bell housing-to-engine bolts to 25 foot-pounds and the the bell housing-to-transmission bolts to 53 foot-pounds. Use blue threadlocker on all but the bell housing-to-engine bolts.
- "How to Rebuild Small-Block Ford Engines"; Tom Monroe; 1987
- "Ford Windsor Small-Block Performance"; Isaac Martin; 1999
Things You'll Need
- Floor jack
- Jack stands
- Basic hand tools
- Paint marker
- Engine hoist
- Drill and 1/8-inch bit
- Self-tapping screws
- Rear main seal
- Torque wrench
- Blue threadlocker
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.