Rear Main Bearing Oil Seal

Split-type crankshaft rear oil seals may be replaced without removing crankshaft, using the following procedure:

1. Loosen all main bearing bolts, lowering crankshaft not to exceed 1/32". Remove rear main bearing cap, remove seal half from cap. Remove upper seal half with suitable tool, being careful not to scratch or damage crankshaft journal or seal surfaces.
2. Remove oil seal retaining pin from bearing cap (if equipped). Discard pin. Dip seal halves in engine oil. Install upper seal in groove with undercut side of seal toward front of engine by rotating it on seal journal until 3/8" protrudes below parting surface. See Fig 1. Tighten main bearing cap bolts.
   Fig 1: Split Lip Type Rear Main Bearing Oil Seal

   Courtesy of FORD MOTOR CO.
3. Install lower seal in rear bearing cap with undercut side towards front of engine, allowing seal to protrude 3/8" above parting surface.
4. Apply thin coating of oil resistant sealer to cap at rear of top mating surface. Install main bearing cap and tighten bolts.
   NOTE: Do not apply sealer to area forward of side seal groove.