a. remove timing gear cover
b. remove flywheel housing
c. remove pistons and connecting rod assemblies
d. remove crankshaft rear seal and wear sleeve
e. remove crankshaft front seal and wear sleeve
NOTE: Check the bearing caps for a number as to their location. If a number can not be seen, put a number on the left side of cylinder block and bearing cap.
1. Remove bolts (1) that hold main bearing caps (2) to the block, and remove main bearing caps (2).
2. Install one of the bolts from the front pulley in each end of the crankshaft.
3. Fasten a hoist to crankshaft (3), and remove crankshaft (3) from the block. The weight is 159 kg (350 lb).
NOTE: If new main bearings are not to be installed, keep old bearings with identification as to their location in cylinder block.
4. Use Tooling (A) to remove the crankshaft gear.
5. Use Tooling (B) if necessary to remove the dowel and the pin.
If the crankshaft journals and bores for the block and rods were measured at disassembly and found to be within specifications, no further checks are necessary. However, if the serviceman still wants to measure the bearing clearances, Plastigage is recommended. Lead wire, shim stock or use of a dial bore gauge can damage the bearing surface.
The serviceman must be very careful to use Plastigage, Tool (B) correctly. The following points must be remembered:
- * Make sure that the backs of the bearings and the bores are clean and dry.
- * Make sure that the bearing locking tabs are properly seated in their slots.
- * The crankshaft must be free of oil where the Plastigage touches it.
- * If the main bearing clearances are checked with the engine upright or on its side, the crankshaft must be supported. Use a jack under an adjacent crankshaft counterweight and hold the crankshaft against the crown of the bearing. If the crankshaft is not supported, the weight of the crankshaft will cause incorrect readings.
- * Put a piece of Plastigage on the crown of the bearing half that is in the cap. Do not allow the Plastigage to extend over the edge of the bearing.
- * Install the bearing cap using the correct torque-turn specifications. Do not use an impact wrench. Be careful not to dislodge the bearing when the cap is installed.
- * Do not turn the crankshaft with the Plastigage installed.
- * Carefully remove the cap but do not remove the Plastigage. Measure the width of the Plastigage while it is in the bearing cap or on the crankshaft journal. Do this by using the correct scale on the package. Record the measurements.
- * Remove the Plastigage before reinstalling the cap.
When using Plastigage, the readings can sometimes be unclear. For example, all parts of the Plastigage are not the same width. Measure the major widths to make sure that they are within the specification range. Also, experience has shown that when checking clearances tighter than 0.10 mm (.004 in) the readings may be low by 0.013 to 0.025 mm (.0005 to .0010 in). Out-of-round journals can give faulty readings. Also, journal taper may be indicated when one end of the Plastigage is wider that the other.
For complete details concerning measuring bearing clearances, see Engine Bearings & Crankshafts, SEBD0531.
1. Install pin (5) in the crankshaft end until it is extended from the surface 6.4 ± 0.5 mm (.25 ± .02 in)
2. Instant dowel (6) until it is extended from the surface 4.1 ± 0.5 mm (.16 ± .02 in).
3. Heat crankshaft gear (4) to a maximum temperature of 232°C (450°F). Install gear (4) on the crankshaft with the keyway in alignment with dowel (6) and the “V” mark to the outside.
NOTE: The dowel in the crankshaft must be in alignment with the keyway in crankshaft gear (4).
4. Clean the cylinder block and main bearing caps thoroughly.
NOTE: Install the bearings dry when the clearance checks are made. Put clean engine oil on the bearings for final assembly.
5. Install upper half of main bearings (7) in the block.
6. Install one bolt for the flywheel on each end of the crankshaft.
7. Fasten a hoist, and put crankshaft (3) in position in block. Be sure the “V” mark on the crankshaft gear is in alignment with “V” mark on the idler gear.
8. Install main bearings in bearing caps.
NOTE: Be sure tabs (8) on back of the bearings fit in the tab slots of the caps and cylinder block.
9. Use Plastigage (B) to check bearing clearance.
10. Put Plastigage (B) on the bearing.
Be sure main bearing caps (2) are installed so the numbers on the side of the cylinder block are the same as the numbers on the bearing caps, and the arrows on the caps are toward the front of the cylinder block.
11. Put 4C-5593 Anti-Seize Compound on bolts (1). Install bolts (1) and main bearing caps (2). Starting with the tab end of the bearing cap first, tighten each bolt in the bearing caps to a torque of 260 ± 14 N·m (190 ± 10 lb ft). Put a mark on each bolt and bearing cap. Start with the bolt away from (opposite) the tab end of the bearing cap, and again tighten each bolt an additional 120 ± 5 degrees.
12. Remove the main bearing caps. Remove Plastigage (B) from the caps. Check the width of Plastigage (B) to find the bearing clearance. The bearing clearance must be 0.091 to 0.185 mm (.0036 to .0073 in) with new bearings. Maximum clearance with used bearings is 0.25 mm (.010 in).
13. Install the thrust bearings for No.4 main bearing.
NOTE: Install the thrust bearings with the side identification “BLOCK SIDE” toward the cylinder block.
14. Put 4C-5593 Anti-Seize Compound on bolts (1). Install bolts (1) and main bearing caps (2). Starting with the tab end of the bearing cap first, tighten each bolt in the bearing caps to a torque of 260 ± 14 N·m (190 ± 10 lb ft). Put a mark on each bolt and bearing cap. Start with the bolt away from (opposite) the tab end of the bearing cap, and again tighten each bolt (1) an additional 120 ± 5 degrees.
15. Check the end play of the crankshaft with Tooling (A). Be sure the dial indicator is against a machined surface. The end play is controlled by the thrust bearings of No.4 (center) main bearing. The end play with new bearings must be 0.15 to 0.51 mm (.006 to .020 in). The maximum permissible end play with used bearings is 0.89 mm (.035 in).
a. install crankshaft front seal and wear sleeve
b. install crankshaft rear seal and wear sleeve
c. install pistons and connecting rod assemblies
d. install flywheel housing
e. install timing gear cover