Figure 3-128. Idler gear installation

TM 10-3930-634-34

NOTE

When using the following method of bearing

removal, remove only one main bearing cap

at a time, complete inspection and install the

bearing shells and cap before removal of the

next bearing cap.

(2) Remove engine (para 2-5).

(3) Remove the oil pan (para 3-26).

(4) Remove the oil inlet tube and screen (para

(5) Two methods of removal are required, one for

the front and intermediate bearings and a second

method for the rear main bearing.

(6) Remove, one at a time, the front and inter-

mediate bearing shells as follows:

their original positions. Main bearing thrust washers

absorb the crankshaft thrust at each side of the rear

main bearing. Each washer is made up of two halves,

the lower halves are doweled to the bearing cap. The

upper and lower bearing shells are not interchange-

able; the upper bearing shells are grooved, and the low-

er shells are not. If one bearing shell is to be replaced,

all main bearings shells must be replaced.

b. Removal of Main Bearings with Crankshaft In-

stalled.

(1) If removal of the crankshaft is not required

the bearing shells may be removed in the following

manner.

(a) Remove main bearing cap (fig. 3-129) and

remove lower bearing shell (3, fig. 3-130).

(b) Insert a special bolt (standard 1/4 by 3/4-inch

long, with head ground to a thickness of 1/16 inch) into

crankshaft journal oil hole so that the bolt head does

not extend beyond the outer surface of the upper bear-

ing shell. Rotate the crankshaft in a clockwise direc-

tion and roll the upper bearing shell (12) out of the

bearing support.

repeat procedures for each intermediate bearing.

(7) Remove the rear main bearing shells as fol-

lows: