Lower Crankcase Installation

Special Tools

• EN 46109:  Guide Pins
• J 39946:  Crankshaft Socket - 4.0L and 4.6L
• J 45059:  Angle Meter

Fig 1: RTV Sealant Application Points
Courtesy of GENERAL MOTORS CORP.
1. Place a 5 mm (0.197 in) spot of RTV sealant GM P/N 12378521 or equivalent (1) at the two points where the crankshaft rear oil seal meets the split line of the engine block.
Fig 2: Applying RTV Sealant
Courtesy of GENERAL MOTORS CORP.
NOTE: Ensure components being sealed with RTV are assembled within 20 minutes. Components assembled after the RTV has skinned-over, approximately 20 minutes, will not seal properly.
2. Completely fill and slightly overfill the engine block seal groove with a continuous bead of RTV sealant GM P/N 12378521 or equivalent.
3. Ensure the RTV sealant GM P/N 12378521 or equivalent bead is higher then the rail surface (1) by 1.0-1.5 mm (0.0394-0.0591 in).
Fig 3: Applying RTV Sealant
Courtesy of GENERAL MOTORS CORP.
4. Using a suitable tool spread the sealant in the area near the oil drain back passages (1) away from the oil drain back passages toward the outboard edge of the rail surface.
Fig 4: Guide Pins
Courtesy of GENERAL MOTORS CORP.
5. To prevent shifting of the lower crankcase install one of the EN 46109:  pins into a bolt hole in each rail.
Fig 5: Lower Crankcase
Courtesy of GENERAL MOTORS CORP.
6. Install the cleaned lower crankcase onto the engine.
Fig 6: Tapping Lower Crankcase Into Position
Courtesy of GENERAL MOTORS CORP.
7. Using a rubber mallet gently tap the lower crankcase into position.
8. Remove both of the EN 46109:  pins.
Fig 7: Right Upper-To-Lower Crankcase Perimeter Bolts
Courtesy of GENERAL MOTORS CORP.
9. Loosely install the crankcase perimeter bolts on the right side.
Fig 8: Lower Left Crankcase Perimeter Retaining Bolts
Courtesy of GENERAL MOTORS CORP.
10. Loosely install the crankcase perimeter bolts on the left side.
Fig 9: Oil Drain Back Passages
Courtesy of GENERAL MOTORS CORP.
11. Using a small long blade screwdriver clean out any sealant in the oil drain back passages (1).
Fig 10: Sealant Application Locations
Courtesy of GENERAL MOTORS CORP.
NOTE: Ensure components being sealed with RTV are assembled within 20 minutes. Components assembled after the RTV has skinned-over, approximately 20 minutes, will not seal properly.
NOTE: DO NOT apply sealant to the inner seal of the oil distribution plate.
12. Using a NEW oil distribution plate, remove the outer seal (1) if installed, and completely fill and slightly overfill the outer seal groove (1) with a continuous bead of RTV sealant GM P/N 12378521 (Canada P/N 88901148) or equivalent. Ensure the RTV sealant bead is higher than the plate surface by 1.0-1.5 mm (0.0394-0.0591 in).
Fig 11: Guide Pins
Courtesy of GENERAL MOTORS CORP.
13. To prevent shifting of the oil distribution plate install one of the EN 46109:  pins into a bolt hole in each side of the lower crankcase.
Fig 12: Oil Distribution Plate
Courtesy of GENERAL MOTORS CORP.
14. Install the NEW oil distribution plate.
15. Remove both of the EN 46109:  pins.
Fig 13: Oil Distribution Plate Bolts
Courtesy of GENERAL MOTORS CORP.
CAUTION: Refer to Fastener Caution .
16. Install the oil distribution plate bolts and tighten to 10 N.m (89 lb in).
Fig 14: Cleaning Sealant In Oil Drain Back Passages
Courtesy of GENERAL MOTORS CORP.
17. Using a small long blade screwdriver clean out any sealant in the oil drain back passages.
Fig 15: Main Bearing Stud-Head Bolt
Courtesy of GENERAL MOTORS CORP.
18. Install the crankshaft oil scraper plate.
19. Install the main bearing bolts. Ensure the stud-head bolt (1) used for the oil suction tube support bracket is placed in the proper position.
Fig 16: Identifying Main Bearing Bolt Tightening Sequence
Courtesy of GENERAL MOTORS CORP.
20. Tighten the main bearing bolts (1-20) in the proper sequence.
    1. First pass to 20 N.m (15 lb ft ) .
    2. Final pass to an additional 65 degrees using the J 45059:  meter .
Fig 17: Identifying Crankcase Perimeter Bolt Tightening Sequence
Courtesy of GENERAL MOTORS CORP.
21. Tighten the crankcase perimeter bolts in sequence shown to 30 N.m (22 lb ft).
Fig 18: Cleaning Sealant In Oil Drain Back Passages
Courtesy of GENERAL MOTORS CORP.
22. Using a small long blade screwdriver verify that the threaded holes for the oil pan bolts and the oil drain back passages are clear of sealant.
23. Using the J 39946:  socket rotate the crankshaft until the number one piston is at top dead center (TDC) and the crankshaft key way is approximately at the 7 o'clock position.