TM 9-1829A, April 1944
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2021-07-07
Section II: SPJ, SPL and SPM series
15. Description
a.
General:
These are single-magnet types with hair spring mounted above the jewel bracket. SPJ-type has
odometer below center of dial and has a disk-type pointer. SPL-type has odometer in center of dial with
needle-type pointer. All of these types have a revolving field plate. For complete description, operation, and
test procedure refer to paragraphs 2 and 4.
Figure 36: Auto-Lite speedometer (SPJ, SPL and SPM-type), disassembled
16. Disassembly
a.
Remove bezel:
Cut bezel and lift off bezel, gasket, glass and dial backer.
b.
Remove case:
Remove two screws and lift off case and dust washer. Invert case and use as stand to hold
speedometer while repairing.
c.
Remove pointer:
(1)
On SPJ- and SPM-type use tool (T-29 Det 3). Slip paper over odometer and through window in dial.
Insert curved end of tool under dial, and through window against bottom of pointer hub. Pry against hub,
using odometer as a fulcrum. Keep hand over pointer, as it may snap off and become damaged.
(2)
On SPL-type, remove pointer by holding pointer hub with fingers, twisting gently counterclockwise, and
pulling off staff.
d.
Remove dial:
Remove dial screws. Care must be taken to avoid slipping of screw slot and scratching dial.
e.
Remove odometer
(fig. 39): Remove odometer spacing clip with pliers, grip flange of odometer shaft
bushing with pliers and move bushing toward odometer figure wheels, then move same end of shaft forward
until bushing is free of jewel bracket. Remove bushing and spring, then lift odometer assembly free from
jewel bracket. If no work is contemplated on odometer, it is not necessary to remove odometer form jewel
bracket. As these parts are a complete subassembly, the odometer can be removed with the bracket.
f.
Remove hair spring
(fig. 39):
(1)
Remove lock pin by placing one nose of pliers against small end of pin and other nose against top part
of arm on regulator. Tighten grip on pliers until pin is loose, then remove pin.
(2)
Hook jaws of puller (T-66296) under hair spring hub. Screw downward on push pin with pin contacting
end of staff (fig. 26). Increase pressure downward until hub pulls from staff. It may be necessary to pry
hair spring hub up slightly to make clearance for the puller (fig. 27).
g.
Remove front jewel bracket
(figs. 33 and 39): With screwdriver (T-178705) and wrench, remove jewel lock
nut, hair spring regulator, and jewel. Take out two bracket screws and remove front jewel bracket. Do not
lose third gear tension plate on SPL-type, lift out third gear.
h.
Remove field plate and speed cup:
Hold assembly in inverted position. With pliers, grip each staked portion
of field plate and turn outward slightly (fig. 40). Care must be taken to avoid cup distortion and to avoid