Figure 5-27. Gear Cover & Rear Bearing Plate Oil Seals (Model RM-J/1-10G)

TM 5-4110-217-14

(136), fill the space between the seal with a fibrous

5-27. Gear Cover Oil Seal.

grease or stiff cup grease. This will improve sealing.

Refer to figure 5-27.

a. Removal (fig. S1).

(2) When installing the gear cover oil seal

(1) Remove gear cover assembly (135) (para 5-

(136), tap the seal inward until rear (spring side)of

10).

casing is one inch from the mounting face of the gear

(2) Drive out gear cover oil seal (136) out from

cover. Install new style, thin open face seal, 1-7/64

the inside using gear cover drive tool.

inches from mounting face of cover.

(3) Reassemble engine. Refer to paragraphs

b. Reassembly.

5-1 thru 5-26.

(1) Before installing the new gear cover oil seal

Section VIII. CYLINDER BLOCK

and wear with a cylinder bore gauge, telescope gauge or

5-28. Cylinder Block Inspection.

inside micrometer (fig. 5-28). These measurements

should be taken at four places - two at the top and two at

a. Make a thorough check for cracks. Minute

the bottom of piston ring travel.

cracks may be detected by coating the suspected area

d. Record measurements taken lengthwise at the

with a mixture of 25 percent kerosene and 75 percent

top and bottom of the piston travel as follows:

light motor oil. Wipe the part dry and immediately apply

(1) Lengthwise of the block, measure and

a coating of zinc oxide (white lead) dissolved in wood

record as "A" the diameter of the cylinder at the top of

alcohol. If cracks are present, the white coating will

the cylinder where the greatest ring wear occurs.

become discolored at the defective area.

(2) Also, lengthwise of the block, measure and

record as "B" the cylinder diameter at the piston skirt

b. Inspect the cylinder bore for scoring. Check the

travel.

Welsh plugs for a tight, even fit and the fins for

(3) Crosswise of the block, measure and

breakage.

record as "C" the diameter of the top of the cylinder at

the greatest point of wear.

c. Check the cylinder bore for taper, out of round

Change 3 5-17