Figure 4-16. Checking bearing clearance with plastigage.

TM 5-4320-234-34

Figure 4-16. Checking bearing clearance with

Figure 4-17. Installing upper bearing half, using

plastigage.

angular pin.

(6) Clearance must be between 0.0007

(0.0017 cm) and 0.0028 inch (0.0070 cm). If the

clearance is not within these limits, replace the bearings

and recheck the clearance.

(7) Remove and replace the bearings as

follows:

(a) Remove the bearing cap; remove the

bearing from the cap.

(b) Install a pin with an angular head into

the oil hole in the crankshaft bearing journal (fig. 4-15).

pin will force the top bearing half out of its seat.

(d) Position the replacement bearing on

the crankshaft bearing journal. Rotate the crankshaft by

hand. The pin will force the bearing half into position as

shown in figure 4-17.

(e) Install the replacement bearing half

Figure 4-18. Checking bearing clearance with shim

into the cap. Install the cap.

stock.

(8) Check the remaining bearing-to-bearing

journal clearances and replace bearings as necessary.

tolerance. Remove the shim stock and reinstall the

(9) An alternate method of checking bearing

bearings caps.

clearance is as follows:

(10) After you have installed all main bearings,

(a) Oil the bearing and bearing journal

use a dial indicator to check crankshaft end play. If end

with engine oil.

play is not between 0.003 (0.0075 cm) and 0.008 inch

(b) Position a strip of 0.003-inch (0.0075

(0.0200 cm), replace the thrust plate (23, fig. 4-13)

cm) feeler gage, 1/2 inch (1.250 cm) long, on the

which controls the shaft end play.

bearing cap (fig. 4-18).

(11) Install the pistons and connecting rods

(para 4-9c).

with the screws and lockwashers. Tighten the screws to

(12) Install the flywheel housing and flywheel

85 to 95 foot-pounds (11.75 to 13.13 kgm) torque.

(para 4-8c).

(d) Try to turn the crankshaft by hand. If

(13) Install the gear cover (para 4-7c).

you cannot turn the crankshaft or if a very definite drag

(14) Install the oil pan (para 4-5c) and oil pump

is felt, bearing-to-bearing journal clearance is within

(para 4-6c).

4-18