TM 5-3810-289-34
only as a tightly closed line when the surface is wiped
clean. Open indications shall not be closer than 3/16
inch to the edge of the cam.
(e) Circumferential indications (lying at an
angle greater than 15 degrees with the longitudinal
centerline) are not allowable.
(7) Limits of acceptability for valve cams.
(a) Subsurface longitudinal indications:
1. 1/8 inch indications are allowable on the
nose.
2. Light longitudinal indications up to 2 of
the cam width are allowable on the ramp.
3.
Not more than two indications are
allowable on the ramp or nose of any one cam.
4.
Light longitudinal indications not
exceeding two in number are allowable on the base
Figure 3-187. Camshaft removal.
circle of any one cam.
5. Parallel indications must be separated by
at least 'A in. on the ramp and nose by 1/16 inch on the
base circle.
(b) Open longitudinal indications: Open
indications are not allowable except on the base circle.
A maximum of two longitudinal open indications 1/4 inch
long or less will be allowed on the base circle provided
they are not closer together than 1/4 inch and are visible
only as a tightly closed line when the surface is wiped
clean. Open indications should not extend closer than
3/16 inch to the edge of the cam.
(c) Circumferential indications (lying at an
angle greater than 15 degrees with the longitudinal
centerline) are not allowable.
(8)
Limits of acceptability for bearing
surfaces.
(a)
Subsurface
indications
are
Figure 3-188. Camshaft journals measurement.
acceptable.
(b) Open indications: Four open longitudinal
(b)
1500 amperes DC longitudinal
indications are permitted in each section of bearing
magnetizing currents must be used for locating open
provided not more than half of them extend the full width
seams and the presence of non-metallic inclusions; for
of the bearing. Edges of such indications are to be
detecting grinding checks a circular (coil) magnetizing
stoned, not to exceed 0.0005 inch deep.
current of 2000 amperes DC must be used. Limits of
d. Removal of Gear.
accept ability for injector cam:
(1) Remove gear if chipped, cracked or
(c) Subsurface longitudinal indications:
visibly worn.
1. None acceptable on nose.
(2) Gears with three capscrews mounted
2. Short longitudinal indications up to 5/8
thrust bearing must be pulled from the camshaft.
inch long are acceptable in the critical region on the cam
(a) Slide two steel bars, 4 inch by 1 inch
surface, 2 inch before nose, and 3/8 inch after nose.
behind gear and thrust bearing.
3. Not more than two indications allowable
(b) Insert gear puller jaws through access
in the critical region of any one cam.
holes in gear.
4.
Light longitudinal indications not
(c) Tighten puller bolt until gear is free of
exceeding two in number are allowable outside of the
camshaft.
critical regions.
(3) Camshafts with two capscrew mounted
5. Parallel indications must be separated by
thrust bearing.
at least 1/16 in. of metal.
(a) Place camshaft and gear in press.
(d) Open longitudinal indications; Open
Support gear as near hub as possible by using short bars
indications are not allowable except on the base circle.
lying parallel with thrust bearing.
A maximum of two longitudinal open indications inch
long or less will be allowed on the base circle provided
they are not closer together than 'A inch and are visible
3-67
