TM 5-3820-239-15
Table 4-1. Repair and Replacement Standards
Manufacturer's
Maximum
dimensions
andn iolcraeses
i tn eh nc
allowable wear
Desired clearance
and clearance
Component
Minimum
Maximum
Minimum
Maximum
DRIFTER DRILL:
Chuck nut flutes
--
--
--
1/16
Piston to cylinder clearance
--
--
0.000
0.009
Piston to piston stem bearing clearance
--
--
0.000
0.009
Rifle bar flutes
--
--
--
--
1/16
Rifle nut flutes
--
1/16
--
--
--
--
--
Shank to shank aliner clearance
--
--
1/16
Valve to valve chest clearance
--
--
0.000
0.003
TRACTION DRIVES:
Drive shaft OD
2.163
2.165
0.0024L
0.002
0.0002T
Drive shaft, stub OD
1.1803
1.1808
0.0008L
0.0005
0.0001T
Drive shaft, pinion bore OD
0.0005L
0.0010
2.0462
2.0472
0.0010T
Drive shaft ball bearing ID
2.1648
2.1654
0.0024L
0.0002T
0.0006
Drive shaft ball bearing OD
3.9370
0.0016L
0.0006
3.9364
0.0010T
Gear housing, bore OD
0.0016L
0.002
3.936
3.938
0.0010T
Motor pinion ball bearing ID
0.9843
0.9839
0.0010T
0.0001T
0.0004
Motor pinion ball bearing OD
2.0467
2.0472
0.0005
0.0010T
0.0005L
Motor pinion gear OD
0.9844
0.9849
0.0001T
0.0005
0.0010T
Planet gear ID
0.0007T
0.0012
2.8322
2.8334
0.0024T
Planet gear ball bearing ID
1.1811
0.0004
1.1807
0.0001T
0.0008L
Planet gear ball bearing OD
0.0005
2.8341
2.8346
0.0007T
0.0024T
AIR FEED MOTOR:
Bearing stud OD
0.0005
0.008L
0.9835
0.9840
0.0001L
--
--
Connecting rod bushing wall thickness
0.053
0.054
0.107
0.0003L
Crank pinion bearing ID
0.5906
0.0009L
0.0003
0.5909
0.0002T
Crank pinion bearing OD
1.6535
1.6540
0.0013L
0.0005
0.0003L
Crank pinion, small OD
0.5900
0.0009L
0.0003
0.5903
0.0025T
Crank pinion, large OD
0.6270
0.6275
0.0005
0.0015T
0.0002L
Cylinder case, lower crank bearing bore
0.0010
2.0475
2.0485
0.0014L
ID
Cylinder case, upper crank bearing
0.0010
1.8508
1.8518
0.0001T
0.0014L
bore ID
--
--
Cylinder liner ID
0.025
1.7505
1.7530
Drive gear, bearing bore ID
0.0014L
0.0010
2.0485
0.0002L
2.0475
Gear case, crank hearing bore ID
0.0010
1.6538
1.6548
0.0002T
0.0013L
Gear case, inner worm bearing bore ID
0.0008
2.4405
2.4413
0.0007L
0.0015T
Idler wheel bushing ID
0.0010
1.0030
1.0040
0.0030L
0.0045L
Idler wheel shaft OD
0.0045L
0.0005
0.9995
1.0000
0.0030L
Inner worm bearing ID
0.0005
1.1810
0.0015T
0.0005T
1.1805
0.0010
Inner worm bearing OD
2.4420
0.0007L
2.4410
0.0015T
Inner worm wheel bearing ID
0.0005
1.2605
0.0015T
0.0005T
1.2600
0.0010
Inner worm wheel hearing OD
2.8355
0.0015L
2.8345
0.0007T
0.0003L
0.0002
0.0004T
Lower crank bearing ID
0.9843
0.9841
0.0002
Lower crank bearing OD
2.0471
2.0473
0.0014L
0.0002L
Lower throw crank, bearing OD
0.0005
0.9840
0.9845
0.0004T
0.0003L
0.0005
Lower throw crank, pinion ID
0.6255
0.0015T
0.6250
0.0025T
0.0005
Outer worm bearing ID
0.9835
0.9840
0.0015T
0.0005T
0.0010
Outer worm bearing OD
2.4420
0.0003L
2.4410
0.0015T
0.0005
0.0005T
Outer worm wheel bearing ID
1.1810
1.1805
0.0015T
Outer worm wheel bearing OD
2.4420
0.0010
0.0015L
0.0007T
2.4410
0.0003
Piston wrist pin OD
0.3765
0.0013L
0.3762
0.0003L
Piston, wrist pin bore ID
0.3775
0.0007
0.0003L
0.0013L
0.3768
4-2
