Removal and Replacement
Main Bearing Replacement
The main bearings are serviced in-vehicle. They must be replaced one-at-a-time in order to properly support the crankshaft. The upper and lower main bearing shells are NOT interchangeable. The upper and lower main bearings are "select fit" to achieve proper oil clearances Procedures.
1. Disconnect and isolate the negative battery cable.
2. Remove the spark plugs Spark Plug - Removal
3. Remove the power steering pumpPower Steering Pump - Removal.
4. Remove the oil pan, oil pump pick-up and engine oil pump Engine Oil Pump - Removal
5. Remove the eight main bearing cap bolts from the windage tray in the sequence shown and remove the windage tray (1).
NOTE: Typical V6 engine configuration shown.
6. Remove the eight main bearing tie bolts in the sequence shown.
CAUTION: DO NOT use a number stamp or a punch to mark main bearing caps, as damage to main bearings could occur.
NOTE: Main bearing caps are not interchangeable and are marked to insure correct assembly.
7. Mark the main bearing cap positions using a permanent ink marker or a scribe tool.
NOTE: Typical V6 engine configuration shown.
CAUTION: Replace only one main bearing at a time while all other main bearing caps remain properly tightened. If all main bearing caps are removed, the weight of the unsupported crankshaft will damage the crankshaft oil seals.
NOTE: Replace the main bearings in the following order; 2, 3, 1, 4.
8. Remove the two cap bolts (2) and remove the main bearing cap (1).
9. When removing the No. 2 bearing cap, also remove the thrust washers (5).
10. Slide the upper main bearing half (6) out from between the crankshaft and the engine block.
11. If required, select fit new main bearings to the engine block Procedures
12. Lubricate the upper main bearing half (6) with clean engine oil and slide the bearing into position.
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NOTE: Typical V6 engine configuration shown.
13. When installing thrust washers (1) at the No. 2 main bearing location, use the following procedure:
a. Move the crankshaft forward to the limit of travel. Lubricate and install the front thrust washer (1) by rolling the washer onto the machined shelf between the No. 2 upper main bulk head and crankshaft thrust surface.
b. Move the crankshaft rearward to the limit of travel. Lubricate and install the rear thrust washer by rolling the washer onto the machined shelf between the No. 2 upper main bulk head and crankshaft thrust surface.
CAUTION: The main bearing cap bolts are tightened using a torque plus angle procedure. The bolts must be examined BEFORE reuse. If the threads are necked down the bolts must be replaced.
14. Check the main bearing cap bolts for necking by holding a scale or straight edge against the threads. If all the threads do not contact the scale (2) the bolt must be replaced.
NOTE: Typical V6 engine configuration shown.
15. Lubricate and install the lower bearing half (3) onto the main cap (1).
16. Install the main bearing cap (1) with two inner main bearing cap bolts (2) tightened to 20 Nm (15 ft. lbs.) plus 90°.
17. Repeat the previous steps for main bearings 3, 1 and 4.
18. Measure crankshaft end play Procedures
19. Install the windage tray with eight main bearing cap bolts. Tighten the bolts in the sequence shown to 21 Nm (16 ft. lbs.) plus 90°.
NOTE: Typical V6 engine configuration shown.
20. Install the eight main bearing tie bolts. Tighten the bolts in the sequence shown to 28 Nm (21 ft. lbs.).
21. Install the engine oil pump, oil pump pick-up and oil pan Engine Oil Pump - Installation
22. Install the power steering pump Power Steering Pump - Installation.
23. Install the spark plugs and ignition coils Spark Plug - Installation
24. If removed, install the oil filter and fill the engine crankcase with the proper oil to the correct level Service and Repair
25. Connect the negative battery cable and tighten nut to 5 Nm (45 in. lbs.).
26. Operate the engine until it reaches normal operating temperature.