TM 9-1829A, April 1944
40/100
2021-07-07
magnet shaft collar and rear thrust washer, but do not pull magnet out of frame at this time, as flared end of
magnet shaft will score the frame bearing surface. Using fixture (T-170666 with Det. 6, fig. 61) tighten down
handle to smooth out flare in magnet shaft.
Caution: Care must be taken to make sure that fixture does not
come in contact with steel portion of magnet, causing it to be weakened.
After smoothing out flare use safety-
edge file (T-170757) to remove any remaining flare or burs from end of magnet shaft. If these operations are
done carefully the magnet can be pulled out of the frame with the fingers without scoring.
Figure 47: Removing magnet shaft collar, using dismantling wrench (T-170654)
h.
Remove oil wick:
Insert punch in plug and tap lightly. This will push wick and plug through into magnet
shaft bearing hole in frame.
25. Cleaning, inspection, and repair of parts
a.
General cleaning:
Thoroughly clean hair spring, speed cup, second gear, third gear, odometer drive gears,
reset shaft. frame, brackets, springs, screws, and metal washers with brush and dry-cleaning solvent. Make
sure to remove every trace of grease, dirt, and lint so that any defects will be easily found. Carefully dry parts
with compressed air. Wipe other parts clean with a rag.
b.
Main frame:
Inspect magnet shaft bearing hole. If scored or worn, replace with new frame assembly. To test,
insert the end of a new magnet shaft into bearing hole about
1
/
2
inch. Test clearance, particularly at inner end
of bearing. Wear in excess of 0.002 inch requires frame replacement. If the second gear bushing, the field
plate, or the intermediate gear are worn or missing, replace the entire frame assembly.
c.
Magnet:
Inspect first gear. If visibly worn or nicked, replace magnet (including first gear).
d.
Second and third gears:
If gear teeth are worn or nicked replace.
e.
Speed cup and staff:
Inspect speed cup. If cup or staff is bent, replace.
f.
Hair spring:
Inspect hair spring. If kinked or bent, replace.
g.
Odometers:
Clean surface of odometer rolls, if necessary, by rubbing lightly with clean, soft chamois. If
odometer is defective, replace complete odometer.
h.
Front jewel bracket and front jewel:
Inspect bracket. If bent or stop pin is loose, replace. Inspect jewel. If
worn out-of-round, replace.
26. Assembly
a.
Install magnet (including first gear):
Place magnet front thrust washer (two ears) on magnet shaft with
turned ear pointing away from magnet. Apply a light coat of No. 00 grease, O.D., to magnet shaft and first
gear (not to magnet) and insert magnet in frame. Place rear (round) thrust washer and magnet shaft collar
over end of magnet shaft. Using magnet assembly fixture (T-170666 with Det. 1), tighten down (fig. 65) until
collar is pressed all the way onto shaft.
Caution: Care must be taken when using fixture to make sure that it
does not come in contact with steel portion of magnet, causing it to be weakened.
If a new magnet is used, be
sure to remove keepers. Using fixture (T-170666 with Det 6), flare end of magnet shaft (fig. 48). Take up all
end play. To establish proper end play, use magnet dismantling wrench (T-170654) (fig. 47), and start shaft
out by tightening down wrench handle
1
/
2
turn, or less. The correct end play (0.005 inch to 0.007 inch) can
be gaged by inserting a feeler between the collar and rear thrust washer.