TM 9-1829A, April 1944
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2021-07-07
all end play out of magnet shaft, check thespeed cup staff play with 0.003 inch feeler gage (ST-263-31).
There should be 0.003 inch end play in speed cup staff, leaving 0.002 inch end play in magnet shaft,
which is the correct adjustment or a total of 0.005 inch in both places.
h.
Install hair spring
(fig. 39):
(1)
Rotate speed cup counterclockwise until it comes to rest against stop, then carefully place hair spring
with tweezers on staff in such a position that when staff is rotated in a clockwise direction hair spring
will wind up and when pinned there will be a slight tension holding speed cup stop against jewel bracket
stop.
(2)
With special drift (T-29 Det. 2) and hammer, tap spring hub lightly until it is in the same plane as the
hole in the regulator. This position will be approximately
1
/
32
inch above the jewel. Insert end of hair
spring in regulator and press lock pin in with pliers. If hair spring does not lie in a true horizontal position,
adjust by bending with tweezers, at a point where it engages lock pin. Be sure the turns of the hair spring
do not touch each other in this position. With proper care in this adjustment, spring can be made to lie
flat and have uniform spacing of coils.
Note: It is very important that this adjustment be properly made.
i.
Install odometer
(fig. 39): Aline pinion carriers for proper engagement with jewel bracket. Insert gear end
of shaft in jewel bracket and move toward bracket, completing engagement of pinion carriers with jewel
bracket. Move opposite end of odometer sufficiently to replace spring and bushing on shaft. Grip flange of
bushing with pliers and move toward odometer to compress spring, then swing inward until bushing snaps
into place in bracket bearing. Make sure all pinion carriers are properly engaged with jewel bracket. Install
odometer shaft clip. Oil odometer bearings with watch and clock oil.
j.
Install dial:
Fasten dial to front jewel bracket mounting supports. Do not let screwdriver slip and mar dial.
k.
Install pointer:
Bend the pointer stop arm slightly back of zero position. Hold speedometer in same position
it will be on vehicle, float pointer exactly on zero, and tap into place.
l.
Calibrate:
Refer to paragraph 14.
m.
Install case
(do not install until after calibration): Install main frame dust washer and insert speedometer in
case. Turn to position and install two screws and lock washers with screwdriver.
n.
Install bezel and glass:
Put washer and glass in place, then crimp edge of bezel, tapping lightly with small
hammer as speedometer rests against wooden block.