Crankshaft,Bearings Install.(C,K, G Trks, RPOs L65,L65-CMT)
Crankshaft and Bearings Installation (C, K, and G Trucks, RPOs L56, L65, L65-CMT)There are five crankshaft bearings numbered 1 through 5, as viewed from the front of the engine. There is an arrow on each bearing cap that points toward the front of the engine. The center crankshaft bearing, number three, is the thrust bearing.
The upper crankshaft bearing inserts all have an oil groove and a oil gallery hole from the block in the center of the groove. The upper crankshaft bearing inserts also have additional holes in the groove at 10 o'clock and 2 o'clock to provide oil to the oil spray nozzles. The oil spray nozzles are mounted in the crankshaft bearing bulkheads. The lower bearing inserts do not have an oil groove or holes. During initial assembly, the crankshaft bearings are select4itted to each of the five crankshaft bearing bores. The total diameter size range of crankshaft bearing bores 1 through 5 is 79.826 - 79.850 mm (3,145 - 3.146 in). This range divides into three sizes, represented by the size numbers 1, 2 or 3.
The proper size number is then stamped on the pan rail at the corresponding crankshaft bearing bulkhead. The crankshaft is color-marked in red/orange, blue, or white, near each crankshaft bearing journal. Cross-referencing the size number on the pan rail with the color on the crankshaft indicates the proper bearing selection (See Figure 1).
Crankshaft Bearings are available in standard 0.013 mm (0.0005 in.) and 0.026 mm (0.0010 in.) undersized for select fining, in order to attain proper crankshaft bearing clearance.
Undersized refers to the crankshaft diameter. For service purposes, bearing size combinations provide the following clearances (See Figure 2).
Crankshaft bearing numbers 1, 2, 3 and 4: 0.045 - 0.083 mm (0.0018 - 0.0033 in.).
Crankshaft bearing number 5: 0.055 - 0.093 mm (0.0022 - 0.00 in.).
Important:
The upper crankshaft bearing inserts must have holes for the piston oil spray nozzles, or damage to the engine could result. All engines were assembled with three-hole upper crankshaft bearing inserts in positions 2, 3 and 4, and with two-hole upper crankshaft bearing inserts in positions 1 and 5. Replace the upper crankshaft bearing inserts with the same type as originally installed.
1. Install the upper crankshaft bearing inserts to the block.
2. Install the lower crankshaft bearing inserts to the crankshaft bearing caps.
3. Apply engine oil to the crankshaft bearing inner surfaces (See Figure 3).
4. Install the crankshaft (See Figure 4).
5. Apply a 1/8 inch bead of gasket maker, GM P/N 1052942, or equivalent, on each side of the rear crankshaft bearing cap area (See Figure 5).
Important:
Crankshaft bearing cap bolt sizes are as follows:
^ All inner crankshaft bearing cap bolts on crankshaft bearing 1, 2, 3, 4 and 5 are 12 mm (101 mm long) bolts.
^ All outer crankshaft bearing cap bolts on crankshaft bearing caps 1 and 5 are 12 mm (68 mm long) bolts.
^ All outer crankshaft bearing cap bolts on crankshaft bearing caps 2, 3 and 4 are 10 mm (68 mm long) bolts (See Figure 6).
Notice:
The crankshaft bearing caps are to be tapped into place with a brass or leather mallet before the attaching bolts are installed. Do not use the attaching bolts to pull the crankshaft bearing caps into their seats, as this may damage the bearing cap and/or block.
6. Install the number 1, 2, 4 and 5 crankshaft bearing caps and bearings by tapping into place with a brass or leather mallet.
7. Apply engine oil to the crankshaft bearing cap bolt threads.
8. Install the crankshaft bearing cap inner 12 mm bolts.
Tighten
Tighten the inner 12 mm bolts to 75 N.m (55 lb ft).
9. Install the number 3 crankshaft bearing cap and bearing (thrust bearing) by tapping into place with a brass or leather mallet.
10. Install the crankshaft bearing cap inner 12 mm bolts.
Tighten
Tighten the inner 12 mm bolts to 14 N.m (10 lb ft).
11. Tap the end of the crankshaft first rearward then forward with a lead hammer to line up the crankshaft bearing and crankshaft thrust surfaces.
Tighten
Tighten the inner 12 mm bolts to 75 N.m (55 lb ft).
12. Measure the crankshaft end play with the crankshaft forced forward. Measure at the front end of the number 3 crankshaft bearing with a feeler gauge. The proper clearance is 0.10 - 0.25 mm (0.004-0.010 in.).
13. Tighten all crankshaft bearing cap bolts in the following sequence:
Tighten
^ Retighten the inner 12 mm bolts to 75 N.m (55 lb ft).
^ Tighten the inner 12 mm bolts an additional 90 degrees.
^ Tighten the outer 12 mm bolts (crankshaft bearing caps 1 and 5) to 65 N.m (48 lb ft).
^ Retighten the outer 12 mm bolts (crankshaft bearing caps land 5) to 6.5 N.m (48 lb ft).
^ Tighten the outer 12 mm bolts an additional 90 degrees.
^ Tighten the outer 10 mm bolts (crankshaft bearing caps 2, 3 and 4) to 40 N.m (30 lb ft).
DO NOT tighten the outer 10 mm bolts (crankshaft bearing caps 2, 3 and 4) an additional 90 degrees.
Notice:
Burrs on the block or crankshaft bearing cap, foreign matter between the bearing insert and the block or crankshaft bearing cap, or a faulty bearing insert, could result a lack of clearance, causing the crankshaft to bind.
14. Inspect the crankshaft for binding by rotating the crankshaft. If the crankshaft does not turn freely, loosen the crankshaft bearing bolts, one pair at a time, until the tight bearing is located.