TM 9-1829A, April 1944
28/100
2021-07-07
g.
Install front jewel bracket
(figs. 25 and 33):
(1)
Put front jewel bracket in place on main frame: Enter speed cup staff into jewel. Enter top end of third
gear into locating hole in bracket. Enter locating pin on main frame into locating hole in front jewel
bracket. With front jewel bracket held in place, by hand, see that there is a small amount of end play in
speed cup staff. Note: If there is no end play, jewel must be backed out (fig. 33) until shaft is not tight
when bracket is firmly in place.
(2)
Install front jewel bracket attaching screws and tighten.
(3)
Adjust front jewel (fig. 33) so that there is 0.005 inch speed cup staff end play; hold feeler gage (ST-263-
27) between under side of jewel and shoulder on speed cup staff (fig. 34); screw jewel down lightly
without pressure until jewel touches gage. Hold jewel firmly in this position with tool (T-178705) and
tighten lock nut. Check end play with feeler gage to see if tightening lock nut has altered adjustment.
h.
Install hair spring:
Handle hair spring carefully with tweezers and place on staff in such position that spring
will wind up when staff is rotated in a clockwise direction. With female punch (T-29 Det. 2) and hammer,
tap spring hub lightly until loose end of spring is in the same plane as hole in regulator arm. When in this
position hair spring hub will be approximately
1
/
32
of an inch above jewel. Insert end of hair spring in regulator
and press lock pin into place with pliers. If hair spring does not lie in a true horizontal position, adjust by
bending with tweezers at point where it engages lock pin. With proper care in this adjustment, spring can be
made to lie flat and have uniform spacing of the coils. It is very important that this adjustment be properly
made.
i.
Install odometer
(fig. 25, par. 11 e): Place clutch spring over odometer gear and clutch assembly. Put clutch
on odometer shaft and engage clutch in odometer hub. Note: Care must be taken so that alinement of odometer
pinion carriers is not altered while doing this. Oil odometer shaft with watch and clock oil, and insert clutch
end of odometer shaft in bearing, holding odometer so that pinion carriers are toward palm of the hand with
slots in carriers facing down. Place odometer bearing plate and locating plate on shaft in proper position on
main frame and insert screw through both plates into main frame. Tighten screw. Insert odometer locking
plate into slots in pinion carriers on odometer and fasten to main frame with screw.
Figure 34: Checking speed cup staff end play, using feeler gage (ST-263-27)
j.
Install face dial:
Fasten dial to front jewel bracket with dial screws, taking care not to mar dial.
k.
Install pointer:
Place pointer on staff in a position equivalent to one mile per hour below stop pin. Tap into
place and then lift pointer over stop pin.
l.
Install case
(do not install case until after calibration (par.14)): Place main frame dust washer over neck of
frame and insert in case. Turn to proper position and install and tighten screws and lock washers.
m.
Install glass
(do not install glass until after calibration): Before installing bezel and glass, be sure dial and
glass are clean. Clamp shank of speedometer in vise. Fasten round rubber gasket to groove in bezel with
shellac. Place large bezel gasket on face dial. Lay glass in position on gasket and put bezel in place. Invert
speedometer and hold flat part of bezel so that it is between bead and edge, against edge of a wooden bench.
Press down firmly and tap lightly over the entire edge of bezel.
n.
Lubricate magnet shaft:
Place speedometer on calibrating machine (T-170645), run at 60 miles per hour
and add 2 drops of SAE-10W oil to the oilhole. Saturate a short wick with SAE-10W oil, insert in oilhole and
replace oil wick plug.