Motor and transmission oils differ in smell. With a certain amount of skill, it can be used to determine which of the seals is defective.
Note: There is another way to determine the type of oil. Drop a drop of oil into a thin layer of water in a container. Transmission oil will spread across the entire surface of the water in the form of a rainbow film, while motor oil will remain in the form of a drop, similar to a grain of lentil.
You will need: a screwdriver with a straight blade, a mandrel.
1. Remove the gearbox (see "Removal and installation of the gearbox").
2. Remove the clutch (see "Removing and installing the clutch").
3. Remove the flywheel (see "Removal, defect detection and installation of the flywheel").
4. Inspect the oil seal. If it has lost its seal, oil will be visible leaking from the bottom.
5. Using a screwdriver, remove the seal.
6. Lubricate the working edge of the new oil seal with engine oil, install it in the cylinder block socket, orienting the working edge inside the engine, and carefully tuck the working edge onto the crankshaft journal.
7. Press the seal into the socket until it stops, using a suitable mandrel.
8. Install the removed components in the reverse order of removal.
Note: When installing the flywheel, lubricate the threaded portion of the flywheel mounting bolts with Loctite or any similar anaerobic thread locking compound.