3406C DIESEL ENGINES FOR CATERPILLAR BUILT MACHINES Caterpillar

Crankshaft

Usage:

Remove Crankshaft

Start By:

a. remove timing gear cover

b. remove flywheel housing*

c. remove engine oil cooler**

d. remove oil filter base**

*Put the engine in time before the flywheel housing is removed. See the topic, "Finding Top Center Compression Position For No. 1 Piston" in Testing & Adjusting Manual SENR6471.

**These operations must be done to install Tool (A) on the engine.

Typical Example

1. Fasten the engine on Tool (A). The weight of the engine is 1362 kg (3000 lb).

2. Remove the bolts and nuts that hold air cleaner group (1), pipe assembly (3), bracket assembly (4) and lifting plate (5) as a unit to the engine. Fasten a hoist to the unit and remove it from the engine. The weight of the unit is approximately 39 kg (85 lb).

3. Remove tube assembly (2) from the engine.

Typical Example

4. Install the two bolts to hold the primary fuel filter bracket (6) in place while the engine is turned with Tool (A).

5. Turn the engine to the position shown with Tool (A). Remove rod bearing caps (8) from the ends of the connecting rods. Push the connecting rods away from the crankshaft.

6. Remove the bolts and remove main bearing caps (7) from the crankshaft.

7. Remove thrust plates (9) from the center main bearing journal.

8. Fasten a hoist to crankshaft (10) with tooling (B). Remove crankshaft (10) from the engine block. The weight of the crankshaft is 159 kg (350 lb).

9. Use Tool (C) to remove outer gear (2) from the end of the crankshaft.

10. Use a hammer and chisel to remove the spacer from the crankshaft.

11. Use Tool (D) to remove the gear alignment dowel from the crankshaft.

12. Use Tool (C) to remove inner gear (11) from the end of the crankshaft.

NOTE: If new main bearings are not to be installed, put identification on the old main bearings as to their location in the cylinder block and to which main bearings caps they belong.

13. Remove main bearings (13) from the cylinder block and the main bearing caps.

Install Crankshaft

1. If the dowel was removed from the flywheel end of the crankshaft, install it in the crankshaft to a maximum dimension of 6.4 mm (.25 in).

2. Heat the crankshaft gears to a maximum temperature of 205° C (400° F).

3. The centerline of inner gear key must be in alignment with the centerline of the dowel hole within 0.51 mm (.020 in). Install crankshaft inner gear (14) on the crankshaft.

4. Install the spacer on the crankshaft.

5. Install the dowel in the crankshaft. The dowel must be extended no more than 4.1 ± 0.5 mm (.16 ± .02 in) from the surface of the crankshaft.

NOTE: The dowel in the crankshaft must be in alignment with the notch in crankshaft gear (15).

6. Make sure the "V" mark on the crankshaft gear is toward the outside, and install crankshaft gear (15).

7. Thoroughly clean the cylinder block and main bearing caps.

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NOTICE

Make sure the upper and lower halves of the main bearings are installed so the bearing tabs fit into the notch in the cylinder block and main bearing caps.

NOTE: Install the main bearings dry when the clearance checks are made. Put clean engine oil on the main bearings for final assembly.

8. Install the upper half of main bearings (13) (bearings with oil holes) in the cylinder block.

9. Fasten a hoist to crankshaft (10) with tooling (B) and put it in position on the cylinder block. Make sure the "V" marks on the crankshaft and the idler gear are in alignment and the "K" marks on the camshaft gear can be seen at the outer edges of the idler gear. The timing gears are in correct position.

10. Install thrust plates (9) on both sides of the center main bearing journal. Make sure the plates are installed with side marked "BLOCK SIDE" toward the cylinder block.

11. Install the lower half of main bearings (13) in main bearing caps (7).

NOTE: When the bearing clearance is checked and the engine is vertical position, such as in the vehicle, the crankshaft will have to be lifted up and held against the upper halves of the main bearings to get a correct measurement with the Plastigage. The Plastigage will not hold the weight of the crankshaft and give a correct indication. If the engine is in a horizontal position, it is not necessary to hold the crankshaft up. Do not turn the crankshaft when the Plastigage is in position to check clearances.

12. Put a piece of Plastigage on the surface of the lower main bearing half.

13. Install main bearing caps (7) with the arrow on the bottom surface of the cap toward the front of the cylinder block. Also, the stamped number on the cap must be the same as the cast number on the left side of the cylinder block.

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NOTICE

Do not use an impact wrench to tighten the bolts the additional 120 ± 5 degrees of a turn more.

14. Put 2P2506 Thread Lubricant on the threads of the main bearing cap bolts. Install the bolts and tighten them as follows:

a. Tighten the tab end bolt to a torque of 258 ± 14 N·m (190 ± 10 lb ft).

b. Tighten the opposite end bolt to a torque of 258 ± 14 N·m (190 ± 10 lb ft).

c. Turn the opposite end bolt an additional 120 ± 5 degrees.

d. Turn the tab end bolt an additional 120 ± 5 degrees.

15. Remove the main bearing caps and measure the Plastigage. The main bearing clearance must be 0.091 - 0.185 mm (.0036 - .0073 in) with new bearings. Maximum clearance with used bearings is 0.25 mm (.010 in).

16. Install the main bearing caps again and tighten the bolts as in Step 13.

17. Put the connecting rods in position on the crankshaft. Install rod bearing caps (8) with the bolts and nuts to hold them. See the topic, "Remove & Install Connecting Rod Bearings", for the correct bolt tightening procedure and bearing clearance check procedure.

18. Check the crankshaft end play with tooling (E). The end play is controlled by the thrust plates on the center main bearing. End play with new plates is 0.15 - 0.51 mm (.006 - .020 in). The maximum permissible end play with used bearings is 0.89 mm (.035 in).