Main Bearings and Crankshaft - TM-5-4320-272-340034

(4) Remove the carburetor and manifolds

(8) Check the valve springs for cracks, distor-

(TM 5-4320-272-12).

tion, and other damage. Replace weak or damaged

(5) Remove the air shrouding (para 3-7).

springs.

(6) Remove the governor asembly (para 3-9).

(9) Inspect the spring retainer seats, spring

(7) Remove the gear cover (para 3-10).

seat retaining locks, valve rotators, and valve tappet

(8) Remove the idler gear and shaft (para 3-11).

assemblies for cracks, scoring overheating, and wear.

(9) Remove the oil pan (para 3-12), oil filler

Replace damaged parts.

c Installation.

(para 3-13), and oil pump (para 3-14).

(1) Position the valve tappet assemblies (19,

(10) Remove the pistons and connecting rods

fig. 3-10) in the engine block.

(para 3-15).

(11) Remove the cylinder blocks (para 3-16).

(2) With the valves (18) installed in cylinder

(12) Remove the valve tappets (19, fig. 3-10)

block, assemble valve springs (17), spring retainer

seats (16), valve rotators (14), and valve spring seat

from the engine block.

retaining locks (15). Compress the valve springs with a

(13) Remove the six cap screws (23, fig. 3-11)

valve spring lifter to install the valve locks. Make sure

and lock washers (24) that secure the main bearing

plate (25) to the engine block; using a puller, remove

you install each valve in the guide from which it was

removed.

the bearing plate, gaskets (27 and 28), and shim (26).

(3) After the valve assemblies have been

mounted in the cylinder blocks, you can adjust the

KEY to fig. 3-11:

1. Crank

18.

Piston

tappets. With the tappets in their lowest position on

the camshaft, engine cold, set the intake valve-to-tap-

19.

Sleeve bearing

2. Capscrew

pet clearance to 0.008 inch and the exhaust valve-to-

Piston ring

3. Lock washer

20.

4. Drive pulley

tappet clearance to 0.016 inch. Rotate the camshaft to

Piston ring

21.

Piston ring

22.

locate low positions.

5. Pin

(4) Using a new gasket (13), install valve tap-

Cap screw

23.

6. Nut

24.

7. Lock washer

Lock washer

pet inspection cover (12); secure with screw (10) and

Bearing retainer plate

25.

flat washer (11).

8. Flywheel assembly

(5) Install cylinder head (para 3-8).

Shim

26.

9. Key

10. Oil deflector

27.

Gasket

28.

11. Nut

Gasket

3-18. Main Bearings and Crankshaft

a. Removal.

29.

12. Cap screw

Oil seal

(1) Remove the oil filter from the flywheel

13. Bearing cap

Crankshaft

30.

14. Bearing shell

shrouding (para 3-4).

31.

Gear

(2) Remove the flywheel assembly from the

15. Connecting rod

Key

32.

16. Retaining ring

engine (para 3-5).

Main bearing cap

33.

(3) Remove the flywheel alternator (para 3-6).

17. Piston pin

Main bearing cone

34.

3-18