TM 9-1829A - Figure 95: Replacing Hair Spring, Using Assembly Kit (T-29)

TM 9-1829A, April 1944 65/100 2021-07-07
Speedometer model no.
Pointer deflection (in
degrees) at 60 mph (1000
rpm)
1
Speedometer model no.
Pointer deflection (in
degrees) at 60 mph (1000
rpm)
1
509-DZ
235
529-CC
141
509-EA
141
529-CD
205
509-EB
113
529-CJ
140
529-Y
170
529-CL
205
529-AJ
205
584-F
207
529-AL
210
584-AM
205
529-BG
168
584-AL
205
529-BH
205
585-AM
197
529-BR
197
585-AX
161
529-BX
113
585-BE
205
529-BY
205
596-BP
183
529-CA
197
596-BS
199
e. Assemble speed unit: Place speed cup on anvil of hair spring assembly fixture (T-29 Det 5). Place hair spring
over end of staff with loose end pointing counterclockwise, if instrument has clockwise face dial. If instrument
has counterclockwise face dial, then the loose end of the hair spring should point in a clockwise direction.
Using female punch (T-29 Det. 2), carefully drive hair spring on staff leaving about
1
/
8
inch clearance between
hair spring collet and speed cup (fig. 95).
Figure 95: Replacing hair spring, using assembly kit (T-29)
1
As the position of the numerals on the dial vary a great deal on different model speedometers, it is necessary to
take this fact into consideration when selecting the proper hair spring to go with each magnet. Therefore, the above
list is provided showing the angle (measured in degrees) that the pointer travels between zero dial reading and 60
miles per hour dial reading. If the model number of the speedometer being repaired does not appear in above list,
the angle of pointer travel from zero to 60 miles per hour on the dial may be easily determined with a protractor.