TM-9-2320-280-34
TRUCK, UTILITY: M998 SERIES
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
JANUARY 1996
TM-9-2320-280-34 - Page 90 of 1258
TM 9-2320-280-34
3-15.
REAR MAIN OIL SEAL REPLACEMENT
This task covers:
a.
Removal
b.
Installation
INITIAL SETUP:
Applicable Models
Manual References
All except 'A2" models
TM 9-2320-280-10
TM 9-2320-280-20
Tools
TM 9-2815-237-34P
General mechanic's tool kit:
automotive (Appendix G, Item 1)
Equipment Condition
Oil pump removed (para.
3-16).
Materials/Parts
Drivebelts loosened (TM 9-2320-280-20).
Two seals (Appendix E, Item 172)
Anerobic gasket sealer (Appendix B, Item 45)
General Safety Instructions
Lubricating oil (Appendix B, Item 32)
Cleaning will be done in a well-ventilated area and
Dry-cleaning solvent (Appendix B, Item 14)
a fire extinguisher will be kept nearby when solvent
Adhesive (Appendix B, Item 1)
is used.
Personnel Required
Maintenance Level
One mechanic
Direct support
One assistant
a.
Removal
NOTE
This task is for 6.2 L engine rear main oil seal replacement only.
Disassembly of
6.5 L engine is necessary before replacing 6.5 L engine rear main oil seal Refer to
TM 9-2815-237-34 for 6.5 L engine rear main oil seal replacement.
Before replacement of seal, thoroughly inspect engine crankcase ventilation system,
tubes, rubber hoses, and CDR valve for blockage which may have caused pressure
build-up in crankcase and seal failure.
Correct as necessary.
Gently tap rear main bearing cap from engine with rubber or brass mallet.
1.
Remove two long capscrews (9), two short capscrews (10), and main bearing cap (6) from engine
block (3).
NOTE
The rear oil seal may be a nylon rope or a neoprene rubber.
Perform step 2 for a
nylon rope seal.
Perform step 3 for a rubber seal.
The crankshaft may need to be rotated by front crankshaft bolt to assist in seal
removal.
2.
Screw a sheet metal screw (1) into nylon rope seal (2).
Using pliers, pull nylon rope seal (2) from
engine block (3) seal groove.
Discard nylon rope seal (2).
3.
Using pliers, pull rubber seal (4) from engine block (3).
Discard rubber seal (4).
4.
Remove seal (5) from rear main bearing cap (6).
Discard seal (5).
WARNING
Drycleaning solvent is flammable and will not be used near an open flame.
A fire
extinguisher will be kept nearby when the solvent is used.
Use only in well-ventilated
places.
Failure to do this may result in injury to personnel or damage to equipment.
5.
Using drycleaning solvent, thoroughly clean the seal groove (8), oil relief slot (7), and engine block (3).
3-30
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