2-Piece Seal

4-112
4-112 engines use a rope type rear main bearing oil seal. When service replacement of seal is indicated, a new rubber split seal, Part No. 14069889, should be used. Refer to procedure below when replacing rope type seal with rubber split design.
1. Remove oil pan and oil pump.
2. Remove rear main bearing cap.
3. Remove upper and lower seal, then clean seal channel of oil. Loosening No. 2, 3 & 4 main bearing caps may be helpful when removing and replacing upper seal.
4. Apply a thin coat of sealing compound 1050026, or equivalent, to outer diameter of upper seal. Roll seal into position in block, turning crankshaft to ease installation.
5. Apply sealer to lower seal as described above, and position into main bearing cap.
6. Position a piece of Plastigage onto main journal or bearing, install main bearing cap and torque to specifications.
7. Remove bearing cap and measure Plastigage for proper bearing clearance. If clearance is not within specifications, correct as necessary.
8. Clean Plastigage from journal and bearing, then lubricate bearing lightly.

Fig. 20 Replacing crankshaft rear main bearing oil seal:

Fig. 21 Thick seal identification mark location. 1984 4-121:

9. Apply a 1 mm bead of sealant 1052357 or equivalent to the bearing cap between the rear main seal end and the oil pan rear seal groove as shown, Fig. 20. Keep sealant off main seal and out of drain slot in bearing cap.
10. Apply light coat of engine oil to crankshaft to seal contact surface.
11. Install rear main bearing cap, then torque all bolts to specifications.
12. Install oil pump and oil pan, then start engine and check for leaks.
A new 1-piece rear crankshaft oil seal is available to replace the 2-piece seal previously used on 1983 and some 1984 engines. Some 1984 and all 1985---88 engines are assembled with the 1-piece seal. The new seal should be used on early models if replacement is necessary. Before replacing a rear oil seal, make absolutely sure it is the exact source of leakage. On 1984 models, once it has been determined that the seal must be replaced, it is necessary to determine the type of seal (thin or thick) installed in the engine, Fig. 21. Refer to the appropriate following procedures.