If traces of oil leakage through the crankshaft seals are detected, first check whether the crankcase ventilation system is clogged or whether its hoses are pinched, and repair the faults if necessary. If the oil leakage does not stop, replace the seals.
A sign that the front crankshaft oil seal needs to be replaced is oil leaking through its edge. The oil is then splashed by the rotating crankshaft pulley, causing the entire front of the engine and the timing belt to become oily.
To replace the front crankshaft oil seal, follow these steps:.
1. Disconnect the wire from the negative terminal of the battery.
2. Set the piston of the 1st cylinder to the TDC position of the compression stroke (see "Setting the piston of the first cylinder to the TDC position of the compression stroke").
3. Remove the timing belt (see "Replacing the timing belt").
4. Remove the crankshaft toothed pulley.
5. Remove the key from the crankshaft nose groove.
6. Using a screwdriver or wire hook, remove the oil seal from the oil pump housing.
7. Lubricate the working edge of the new oil seal with engine oil, install it in the oil pump housing, orienting the working edge inside the engine, and press the oil seal into the pump housing until it stops using a mandrel. You can use a head from a tool kit of a suitable size or an old oil seal as a mandrel.
8. Install all removed parts and assemblies of the timing mechanism in the reverse order of removal.
9. Adjust the timing belt tension (see "Replacing the timing belt").
To replace the rear crankshaft oil seal, perform the following operations.
1. Remove the gearbox (see "Removal and installation of a manual gearbox" or "Removal and installation of automatic transmission").
2. Remove the flywheel or torque converter drive plate (see "Removal and installation the flywheel or torque converter drive disk").
3. Remove the exhaust pipe (see "Replacing the intake pipe").
4. Remove the oil pan (see "Replacing the oil pan seal").
5. Remove the crankshaft position sensor mounting screw...
6. ...and remove the sensor.
7. Remove the crankshaft position sensor timing disk.
8. Remove the two bolts securing the crankshaft rear main bearing cover...
9. ...and remove the lid.
10. Remove the rear crankshaft oil seal from the groove in the cylinder block.
11. Lubricate the working lip of the new oil seal with engine oil.
12. To avoid damaging the working edge of the rear oil seal, install the oil seal using a drift of the appropriate size.
13. Install the crankshaft position sensor timing disk. When installing, align the stampings on the disk with the corresponding holes on the crankshaft flange.
14. Install the removed components and parts in the reverse order of removal.
NOTE: When installing the flywheel or driven disc, lubricate the threaded portion of the flywheel mounting bolts with anaerobic thread locking compound...
...and tighten them evenly in a criss-cross pattern to the torque specified in Appendix 1.
[The material was created based on information from the website CHEVYMAN.RU]