Except 231 cid Engine
See Figures 1 and 2
The rear main bearing seal may be replaced without removing the crankshaft. Seals should only be replaced as a pair. Fabrication of a seal installation tool as shown in the figure will prevent damaging the bead on the cylinder block. The seal lips should face the front of the engine when properly installed.
- Remove the oil pan and oil pump.
- Remove the rear main bearing cap, and pry the seal out from the bottom with a small prybar.
- Remove the upper seal with a small hammer and a brass pin punch. Tap on one end of the seal until the opposite end can be gripped with pliers.
- Clean the bearing cap and the crankshaft.
- Coat the lips and bead of the seal with a light engine oil. Do not get oil on the seal ends.
- Insert the tip of the installation tool between the crankshaft and the seal seat of the cylinder block. Place the seal between the tip of the tool and the crankshaft, so that the bead contacts the tip of the tool.
- Be sure that the seal lip is facing the front of the engine, and work the seal around the crankshaft, using the installation tool to protect the seal from the corner of the cylinder block.
Do not remove the tool until the opposite end of the seal is flush with the cylinder block surface.
- Remove the installation tool, being careful not to pull the seal out at the same time.
- Using the same procedure, install the lower seal into the bearing cap. Use your finger and thumb to lever the seal into the cap.
- Apply sealer to the cylinder block only where the cap mates to the surface. Do not apply sealer to the seal ends.
- Install the rear cap and tighten the bolts to specifications. Install the oil pan and pump as previously described.
See Figure 3
On this engine, the upper half of the rear main bearing oil seal may be repaired, but not replaced, with the crankshaft in place. To completely replace the seal, the crankshaft must be removed. The lower part of the seal may be replaced in the conventional manner when the bearing cap is removed.
- Remove the oil pan and the rear main bearing cap.
- Using a blunt-edged tool, drive the upper seal into its groove until it is tightly packed. This is usually 1 / 4 - 3 / 4 in.
- Cut pieces of a new seal 1 / 16 in. longer than required to fill the grooves and install them, packing them into place.
- Carefully trim any protruding edges of the seal.
- Remove the old seal from the bearing cap, and install a new seal.
- Reinstall the cap and the oil pan.