REAR MAIN CRANKSHAFT SEAL SERVICE SEAL INFORMATION. GMC Truck S15 Pickup - 4WD 1984

For 1990-2009 cars

# REAR MAIN CRANKSHAFT SEAL SERVICE SEAL INFORMATION

1982-1984 S/T TRUCKS WITH 2.0L V6 60 DEG ENGINES

This bulletin cancels and supersedes 84-B-77 (May, 1984.) All copies of which should be destroyed.

If a 2.8L V6 engine exhibits oil leakage from the area of the rear main crankshaft seal, it may be necessary to replace the crankshaft and seal. A new crankshaft, P/N 14089826, is now available to service the 1982-84 2.8L V6 engines. The new crankshaft has had the "knurled" portion of the rear seal area removed. This new crankshaft uses rear seal P/N 14081761 and requires anaerobic sealer P/N 1052756 or Loctite 515 (or equivalent). The seal has helices on the lip along with a garter spring. Installation instructions for the seal are included in the kit.

The following sequene of repair and installation should be followed.

INSTALLATION OF NARROW ONE-PIECE CRANKSHAFT SEAL KIT, P/N 14081761

1. Remove engine and mount on stand in inverted position with coolant and oil drained.

2. Remove the old crankshaft per service manual instructions.

3. With crankshaft out of engine, remove oil seal and clean all sealant and foreign material from cylinder case and bearing cap.

4. Inspect components for nicks, burrs, scratches and matchining defects at all sealing and mating surfaces and crankshaft journals.

5. Apply a 1.0mm bead (.039 inch) of Loctite 515 (or equivalent) sealant 1052756 to O.D. of new seal. Seal should remain on installation tool as received during application of sealant.

6. Push seal and tool assembly onto the rear of the new crankshaft as far as it will go. Position the tool so that the arrow points toward the cylinder case assembly as shown in the instructions.

7. Apply a light coat of engine oil supplement (EOS), P/N 17052376, on crakshaft journals.

8. With the tool in place, set crankshaft in engine, aligning seal in case groove.

9. Remove the installation tool, rotating as shown and discard.

10. Apply a thin coat, approximately 1.0mm (.039 inch) thickness of anaerobic sealant 1052756 to the areas of the rear main bearing cap as shown in Figure No. 1. It is necessary to make sure that the rear main bearing cap is properly sealed to prevent an oil leak between the block and rear main bearing cap. The use of too much sealer on the rear main bearing cap of the crankshaft seal can cause a seal failure and an oil leak. RTV sealant is not to be substituted for the anaerobic sealer, as it will cause an oil leak. Install cap and main bearing. Torque bolts to 95 N.m (70 ft.lbs.)

11. Install remaining caps and main bearings. Torque bolts to 95 N.m (70 ft.lbs.)

12. Install connecting rod bearings and caps Torque to specifications.

13. Complete engine assembly and installations per GMC Service Manual.

Labor Operation Number: J1120

Labor Time Trucks ----------- ------- "S" "T" 7.3 7.8 With A/C .2 .2 With P/S .2 .2 With CCC .6 .6 With Cruise Control - - W/Auto Transmission .3 .3 W/Skid Plate - .2 w/Manual Transmission - 2.0

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.