* TM 5-3895-342-34
Table 1-1. Engine Repair and Rebuild Data Continued
Manufacturer's dimensions
Maximum
Component
and tolerances in inches
Desired clearance
allowable
wear and
Minimum
Maximum
Minimum
Maximum
clearance
Connecting Rod
Clearance between piston pin and bushing
0.0005
0.0010
0.0005
Allowable twist of connecting rod
measured 3 inches from end
0.0002
Crankshaft
Connecting rod journal diameter
1.8100
1.8105
Main journal fillet radius
0.125
Conrad journal fillet radius
0.937
End play of crankshaft in bearing
0.002
0.004
adjustable
Cylinders
Nominal dimension of bore diameter
3.254
3.25
0.005
Governor
Diameter of drive gear shaft
0.4270
0.4275
0.002
Id of drive gear shaft bushing
0.4290
0.4295
0.002
Clearance between shaft end bushing
0.0015
0.0025
Id of fulcrum bore in housing
0.312
0.313
0.002
Fulcrum of shaft diameter
0.309
0.310
0.002
Clearance of shaft in housing bore
0.002
0.004
Od of flyweight spool bushing
0.560
0.0561
0.002
Id of flyweight spool
0.563
0.565
0.003
Clearance between spool bushing
0.002
0.005
Idler Gear
Diameter of idler gear shaft
0.7490
0.7495
0.002
Diameter of shaft bore in gear
0.7510
0.7515
0.002
Clearance of gear bore to shaft
0.001
0.0025
Backlash of idler gear
0.002
0.004
Oil pump
Drive shaft diameter
0.4995
0.5000
0.002
Diameter of shaft bore in pump body
0.5005
0.5015
0.002
Clearance bore to shaft
0.0005
0.0030
Driven gear stub shaft diameter
0.4995
0.5000
0.002
Diameter of bore in driven gear
0.5005
0.5015
0.002
Piston
Allowable wear from diameter of skit
0.005
Clearance skirt to cylinder bore
0.0045
0.0050
Diameter of piston pin bore
0.8593
0.8596
0.0005
Clearance piston pin to piston
0.0000
0.0005
Diameter of piston pin
0.8591
0.8593
0.001
Piston ring
Gap clearance (fitted in cylinder)
0.010
0.020
0.015
Clearance of ring in piston groove:
Groove No. 1
0.002
0.0035
0.002
Groove No. 2
0.0015
0.0025
0.002
Groove No. 3
0.001
0.003
0.002
Valve lifters
Diameter of guide holes in block
0.6245
0.6255
0.002
Clearance valve liter to hole
0.005
0.0025
Diameter of valve lifter
0.623
0.624
Angle of seat
45
Stem diameter
3.405
0.3415
0.002
Stem to guide hole clearance
0.0025
0.0045
0.007
Nominal dimension of valve guide hole
0.344
0.345
0.002
Valve seats (inserts)
Nominal dimension of seat diameter
1.3765
1.3770
Angle of seat
45
Angle of relief
45
0.001
0.003
Scale reading compressed to 1.27 inch
51 lb
53 lb
Scale reading compressed to 1.546 inch
38 lb
39 lb
1-3