TM 9-1829A, April 1944
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2021-07-07
Figure 22: Flaring magnet shaft, using fixture (T-170666 with Det. 6)
b.
Install oil wick:
Saturate oil wick in watch and clock oil and insert wick inside of speedometer neck. Enlarge
sealing plug with small screwdriver blade and position in hole on top of oil wick and tap in place with small
mallet or screwdriver handle.
c.
Install second gear:
Lubricate teeth on second gear lightly with No. 00 grease O.D. Place thrust washer on
tenon at gear end of second gear. Bushing has small taper relief on end which enters frame. Tap bushing into
main frame with small rawhide mallet. Adjust bushing to give second gear 0.010 inch to 0.015 inch end play.
Tap bushing squarely so that no burs will result.
d.
Install speed cup and field plate:
Place one drop of watch and clock oil in jewel hole on upper end of first
gear and magnet (oil may be applied with clean, small nail or wire dipped in oil supply). Lubricate both ends
of speed cup spindle sparingly with watch and clock oil, and place lower end of staff in magnet jewel. Hold
field plate over speed cup in frame, with relief for third gear over third gear bearing in frame, before dropping
down in position over speed cup spindle. Stop on speed cup must rest above stop at left of field plate. Retain
field plate loosely in position with two screws. Insert hair spring up to first bend into regulator arm hole and
retain in position with taper pin.
e.
Install rear reset shaft
(applies only to units with trip odometer and solid rear reset shaft): Slide reset shaft
into hole at right, lower end of frame. Secure in place from back of frame with resetshaft spring, snapping
lower coil of spring into groove in shaft.
Note: Flexible reset shafts are serviced as an integral part of the
main frame. See note at end of following subparagraph g for front reset shaft.
f.
Install third gear:
Lubricate teeth on third gear with No. 00 grease, O.D. and install in main frame. Helical
gear meshes with worm of second gear.
g.
Install front jewel and bracket assembly:
Place small composition thrust washer over upper end of speed
cup spindle. Install front jewel and bracket assembly on main frame and retain lightly with two screws. Make
sure that speed cup spindle and third gear upper bearings are assembled properly through jewel and bracket.
Before finally tightening jewel bracket screws, make sure there is sufficient end play in the spindle to prevent
jewel damage or broken spindle. With the first gear pushed forward, adjust jewel in bracket to give speed cup
spindle 0.003 inch to 0.006 inch end play. Use tool (846854) for “L” and (846862) for “N” series
speedometer.
Note: Front reset shafts must be installed in jewel bracket before bracket is attached to frame.
h.
Final positioning of field plate:
Turn frame assembly upside-down and adjust field plate so that it is
concentric with speed cup. Rotate speed cup by rolling spindle between fingers to check uniformity of gap
between speed cup and field plate while frame is inverted. When field plate is correctly positioned, tighten
screws to retain and recheck concentricity.
i.
Assemble and install trip odometer
(applies only to quick-reset odometer): Place drive sleeve spring and
drive sleeve over the right-hand end of trip odometer shaft. Install this assembly in the main frame (slots in
the pinion carriers must be assembled over the retainer on field plate). First insert the left end of the shaft
from inside the frame. Move into position by sliding shaft through thrust washer at right end (while washer
is held in position with tweezers). Install long odometer spacer and bushing over the left end of trip odometer
shaft. Secure shaft in place with retainer. Insert one slotted spacer on odometer shaft between frame and inside
legs of shaft retainer.
j.
Assemble total odometer:
Insert grooved end of odometer shaft through hole from right side of frame.
Assemble one thrust washer, fourth worm, and dummy wheel on odometer shaft. Place a small amount of