Requires removal of transfer case, transmission, flywheel and need a special tool to install seal, may be able to rent from parts house. Different tool for V8 & V6. Once piece seal.

Crankshaft Rear Oil Seal Replacement

Tools Required

J 35621-B Rear Main Seal Installer

Removal Procedure

1. Remove the transmission assembly.
2. Remove the engine flywheel.
   
   
   
3. Remove the crankshaft rear oil seal from the crankshaft rear oil seal housing. Insert a suitable tool into the access notches and then carefully pry the crankshaft rear oil seal from the crankshaft rear oil seal housing.
4. Discard the crankshaft rear oil seal.
5. Clean off any dirt or rust in the area.

Installation Procedure

1. Apply a small amount (2 to 3 drops) of clean engine oil to the bore of the crankshaft rear oil seal housing.
2. Apply a small amount (2 to 3 drops) of clean engine oil to the outside diameter of the engine flywheel pilot flange.
3. Apply a small amount (1 drop) of clean engine oil to the outside diameter of the flywheel locator pin.
4. Apply a small amount (2 to 3 drops) of clean engine oil to the crankshaft seal surface.
5. Inspect the J 35621-B flange for imperfections that may damage the crankshaft rear oil seal. Minor imperfections may be removed with a fine grade emery cloth.

   Important: DO NOT allow oil or any other lubricants to contact the seal lip surface of the crankshaft rear oil seal.
   

6. Remove the sleeve from the crankshaft rear oil seal.
7. Apply a small amount (2 to 3 drops) of clean engine oil to the outside diameter of the crankshaft rear oil seal.
8. Install the crankshaft rear oil seal onto the J 35621-B .
9. Install the J 35621-B onto the rear of the crankshaft and hand tighten the tool bolts until snug.

   Notice: Proper alignment of the crankshaft rear oil seal is critical. Install the crankshaft rear oil seal near to flush and square to the crankshaft rear oil seal housing. Failing to do so may cause the crankshaft rear oil seal or the crankshaft rear oil seal installation tool to fail.

10. Install the crankshaft rear oil seal onto the crankshaft and into the crankshaft rear oil seal housing.
    1. Turn the J 35621-B wing nut clockwise until the crankshaft rear oil seal is installed near to flush and square to the crankshaft rear oil seal housing. Increased resistance will be felt when the crankshaft rear oil seal has reached the bottom of the crankshaft rear oil seal housing bore.
    2. Turn the J 35621-B wing nut counterclockwise to release the J 35621-B from the crankshaft rear oil seal.
11. Remove the J 35621-B from the crankshaft.
12. Wipe off any excess engine oil with a clean rag.
13. Install the engine flywheel.
14. Install the transmission assembly.