
TM 9-1829A, April 1944
74/100
2021-07-07
40. Assembly and calibration
a.
Replace drive gear assembly:
If ball-bearing type, lubricate balls with white petroleum jelly. If sleeve-type
bearing, lubricate drive gear shaft with several drops of clock oil. Place assembly in frame and tighten set
screw securely, then tighten lock nut.
b.
Replace governor assembly:
Cover bearing balls with petroleum jelly and place in ball races (nine balls in
each race). Place special screwdriver (T-51742) in slot in upper spider (fig. 110), spread spider, and pull out
governor shaft.
Figure 110: Removing governor shaft
Lubricate shaft with white petroleum jelly and replace. Then pull screwdriver out of slot in upper spider. Start
upper ball race lock nut onto upper ball race about two or three threads. Place upper end of governor shaft in upper
ball race, then lower end of shaft in lower ball race. Tighten down upper ball race (fig, 109), allowing about 0.002
inch end play in governor shaft. While holding upper ball race with screwdriver, tighten lock nut securely (fig.
108). Place special screwdriver (T-51742) in slot in upper spider and move flyball assembly on governor shaft
(fig. 111) until there is about
1
/
64
inch clearance between upper spider and upper ball race. Then remove
screwdriver from slot and tighten set screw (O, fig. 105). Test for free turning.
Figure 111: Adjusting clearance between upper spider and upper ball race
c.
Replace pointer mechanism:
Lubricate gears with small amount of watch and clock oil. Place pointer
mechanism in frame, making sure that shoe is properly positioned (P, fig. 105). Fasten securely with two
screws (fig. 107). Replace maximum hand reset lever spring.
d.
Replace face dial:
When placing face dial on frame make sure that maximum hand reset lever is in proper
position so that maximum hand returns to pointer stop pin when this lever is depressed. Also be sure ratchet
adjustment is correct (par. 39 b). Fasten face dial in place (two screws).