CHAPTER 4
DIRECT AND GENERAL SUPPORT,
AND DEPOT MAINTENANCE INSTRUCTIONS
Section I. REPAIR AND REPLACING STANDARDS
287. Repair and Replacement Standards
Tables 3 and 4 list the manufacturer's sizes, tolerances, clearances, and allowable wear and clearance for the carrier
and crane engine.
Table 3. Crane Engine Repair and Replacement Standards
Manufacturer's
dimensions and
Desired
Maximum
Maximum
tolerances in
clearance
allowable
allowable
inches
wear
clearance
Min.
Max.
Min.
Max.
CRANE ENGINE
Piston-to-cylinder clearance -----------------------------
0.004
0.006
0.010
Piston pin hole in piston (dia) ---------------------------
1.2498
1.2501
0.0002
Ring groove width:
1st-------------------------------- ------------------------
0.097
0.098
2d and 3d -------------------------------- --------------
0.1265
0.1275
4th -------------------------------- -----------------------
0.251
0.252
Ring land dia:
1st-------------------------------- ------------------------
4.216
4.220
2d -------------------------------- ------------------------
4.220
4.224
3d and 4th-------------------------------- --------------
4.226
4.229
Skirt dia (perpendicular-to-pin bore)-------------------
4.245
4.247
Piston Rings
1st compression:
Width-------------------------------- --------------------
0.0925
0.0935
Thickness -------------------------------- --------------
0.208
0.218
Gap clearance -------------------------------- --------------
0.017
0.032
0.060
Side clearance -------------------------------- --------------
0.0035
0.0046
0.0055
2d and 3d compression:
Width-------------------------------- --------------------
0.128
0.124
Thickness -------------------------------- --------------
0.208
0.218
Gap clearance -------------------------------- --------------
0.017
0.032
0.060
Side clearance -------------------------------- --------------
0.0025
0.0035
0.0045
4th (oil) ring:
Width-------------------------------- --------------------
0.248
0.249
Thickness -------------------------------- --------------
0.208
0.208
Gap clearance -------------------------------- --------------
0.017
0.032
0.060
Side clearance -------------------------------- --------------
0.002
0.004
0.006
AGO 6819A
189
