TRUCK SERVICE MANUAL
ENGINE
not be out-of-round more than 0.025 inch [0.64 mm]
Hole may be welded if necessary.
when located in centers of socket and ball. Push tubes
3. Fill lubricating oil holes in bushing with semi-soft
that are bent have usually had the adjusting screws over-
soap to prevent chips from entering oil passages during
torqued,
boring operation. Chamfer each end of bushing with 60
deg. angle cutter in a slow speed drill press.
4. Bore bushings to 0.7495 to 0.7505 inch [19.037
to 19.063 mm]. Blow soap from oil holes and clean
lever. Check bored bushings with ST-195 Plug Gauge.
ASSEMBLY
1. If removed, press in new lever insert. Make sure
insert is securely seated. If new injector insert is
installed, a new injector push tube must be used.
2. Install rollers with 0.006 inch [0.15 mm] feeler
stock beneath roller and next to lever as a support.
Press pins through rollers and levers, then remove feeler
stock. Secure with roll pins.
3. Assemble levers and shafts in housing. Make
sure injector lever is in center position of each assembly.
Cam rocker levers must be installed in housing with push
tube sockets and housing dowel pin holes topside.
4. Install "dummy" screw in shaft. A "dummy"
screw is used at this point to prevent lockscrew
breakage. Screws have tendency to break due to close
shaft-housing fit, causing plug to act as hydraulic ram
when driven in place.
Use ST-1053 Plug Driving
Mandrel with end marked 175831, press plug in until
flush to 0.010 inch [0.25 mm] below edge of hole.
Remove "dummy" screw and install shaft lockscrews.
PUSH TUBES
Each cylinder has exhaust, injector and intake push
tubes. Injector push tube is largest and fits in middle
socket. On engines equipped with compression release,
the exhaust push tube is equipped with collar to match
with milled recess in compression release shaft; the
remaining push tubes are plain. On engines without
compression release, intake and exhaust push tubes
are both plain.
INSPECTION
1. Check injector and valve push tube ball end for
wear with radius gauge. Ball end diameter is 0.623 to
0.625 inch [15.82 to 15.88 mm]. Check for loose ends.
2. Check socket of push tube with ball end of a new
rocker lever adjusting screw or with 1/2 inch [12.7 mm]
check ball, which should "blue in" 80% of seat area.
Push tubes with worn ball ends should never be installed
in new cam follower sockets.
3. Check push tubes to see if they are bent. Tubes
should
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