TM-9-2320-272-24-4
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 4 OF 4
JUNE 1998
TM-9-2320-272-24-4 - Page 46 of 836
TM 9-2320-272-24-4
5-7. CYLINDER LINERS AND BLOCK MAINTENANCE (Contd)
Table 5-4. Cylinder Liner Counterbore.
INSlDE DIAMETER
DEPTH
New minimum
. . . . . . . . . . . . . . . . . . . . . . . .
6.5615 in.
0.350 in.
(166.662 mm)
(8.89 mm)
New maximum . . . . . . . . . . . . . . . . . . . . . . . .
6.5635 in.
0.352 in.
(166.713 mm)
(8.94 mm)
Wear limit . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.412 in.
(10.56 mm)
14.
Ensure cylinder liners (2) protrude 0.003-0.006 in. (0.08-0.15 mm) above the engine block (1) when
they are properly installed.
NOTE
Shims are used to compensate for counterbore depth wear.
Steps 15 through 17 check cylinder liner for proper protrusion
without installing a cylinder liner.
15.
Measure cylinder liner (2) outside flange (4) with micrometer. Do not include bead (3) when taking
measurements.
16.
Measure counterbore ledge (5) depth with gauge block. Ensure counterbore ledge (5) is smooth and
not “cupped” more than 0.0014 in. (.036 mm). Depth must not vary more than 0.001 in. (0.254 mm).
17.
Subtract counterbore depth from cylinder liner (2) outside flange (4) depth to determine amount of
shims or depth of counterbore cut to be made to obtain 0.0036-0.006 in. (0.08-0.15 mm) liner
protrusion.
18.
Install cylinder liner (2) and clamps in engine block (1) without O-rings or crevice seal. Ensure
clamps are installed so there is equal pressure on liner. Tighten clamps 50 lb-ft (68 N•m).
19.
Use feeler gauge to check clearance between lower liner (2) and engine block (1). If clearance is not
within limits specified in table 5-5, check lower O-ring groove inside diameter in engine block (1).
20.
Remove cylinder liner (2) from engine block (1).
21.
Use telescoping gauge to check lower liner bore (6) in engine block (1). Bore (6) should be within
limits set in table 5-5.
Table 5-5. Lower Liner Bore Inside Diameter and Block Clearance.
MINIMUM
Lower liner bore inside diameter . . . . . . . . . . . . . . .
6.124 in.
(155.55 mm)
Lower liner to block clearance . . . . . . . . . . . . . . . . . 0.002 in.
(0.05 mm)
MAXIMUM
6.126 in.
(155.60 mm)
0.006 in.
(0.15 mm)
5-40
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