4-46 TRACTION MOTOR BRUSHES AND BRUSH HOLDERS (cont)
Connect small spring scale to the spring directly over the brush and pull straight up in
line with the brush travel
until the spring is just clear of the brush. The pressure should be between 7.9 and 8.5 pounds (3.6 and 3.7 kg).
Adjust spring pressure as follows:
For coarse adjustment, each spring is adjusted
separately as follows:
Remove cotter pin (9) from ratchet (10) of
spring (11) to be adjusted.
Turn ratchet toward brush holder body
(12) (as viewed from top) to increase
spring pressure, or turn away from brush
holder body to reduce the pressure.
Replace cotter pin (9) through newly
alined holes in ratchet.
For fine adjustment, springs are adjusted simultaneously as follows: (1) Apply screwdriver to slot in support pin
(13) and hold.
Remove single cotter pin (14), located in one end of brush holder body (12), through the support pin (13).
Turn screwdriver through a small angle (about 4-1/2 degrees) away from the brush holder body (12), as
viewed from top, until cotter pin (14) can be inserted on the end opposite the one from which it was
Insert cotter pin (14) on opposite end of support pin (13).
Position two covers (2) and connect latch (1).