assembly (6) shoulder do, n. on pinion staff. Place
modified to a "DF" configuration automatically by
on table of staking frame so hub of
adhering to the closer adjustment tolerances as required
intermediate wheel and hub assembly is in suitable hole.
by his manual.
c. After the above changes have been made,
Insert 0.003 inch feeler gage between intermediate
wheel and bearing plate. Press pinion down and remove
remove data plate, stamp the letters "F" or "DF" as
required after the present part number, reinstall data
l. Reassemble unit. insuring wheel assembly pivots
plate. and reidentify part numbers as follows
are in bearing holes when securing plate assembly (4) to
671CPX4-037 to 671CPX4-037DF
plate assembly (11). Use a short hand "with weighted
671CPX4-037D to 671CPX4-037DF
end cut off and paint removed. Press hand onto hand
671CPU19-015 to 671CPU19-015DF
staff. Hold assembly so prepared hand is in vertical
671CPU19-01D to 671CPU19-015DF
plane, then turn plate between fingers. Any friction will
671CLU4-035 to 671CLU4-035DF
be indicated by tendency of hand to rotate with
671CLU4-035D to 671CLU4-035DF
assembly. Any existing friction must be removed before
replacing unit in case.
Lubricate as follows:
and push pin (40) out of adjustment knob stem (41).
a. A powdered lubricant, (item 6, table 1-31 if used
Remove the stem. Examine leather flasher (42). If
on each end of compensating pins of aneroid diaphragm,
conditions warrant, replace washer.
will improve performance and substantially reduce
n. Before leather washer is replaced it must be
soaked in a hot mixture of the following:
b. Note in which detent compensating pins are
Beeswax ...................60 parts by weight
located. Carefully remove pins. Fill dentents with
Tallow .......................20 parts by weight
powdered lubricant. Replace pins and with fingers.
Petrolatum ................20 parts by "weight
using very little pressure.
roll compensating pins
o. After soaking washer in mixture, with draw
between two bearing surfaces. Remove pins and again
washer and remove excess solution. Replace washer in
fill detent with lubricant. Repeat until a minute amount of
recess of case, smooth side up. Replace retaining ring
powdered lubricant is packed into detent. When
(39. figure 2-1) on hub of pinion (43) but not in groove.
properly lubricated, compensating pins will rotate
Place pinion in recess of case with hub toward front.
smoothly from extremely light pressure. Remove excess
Insert knob adjustment stem '411 through case into hub
lubricant from surfaces of compensator and diaphragm
of pinion. Align holes, insert pin (40). and secure pin
with retaining ring (39).
c. Using a 0.010 wire brush, lubricate all pivots with
p. Do not remove idler gear (46) unless absolutely
necessary, as idler shaft (44) must be airtight. If
necessary, place case, front down, on wooden block with
2-7. Reassembly and Testing.
idler shaft over suitable hole in block. Tap idler shaft out
Reassemble in reverse of disassembly as follows:
of case with pin punch.
Before reassembling mechanism, check fit
q. Place case, front up, on bench. Place spring
tension washer (45) and idler gear (46), hub down, in
and center boss of body assembly (47).
recess of case. Spring tension washer is toward rear of
b. Place top plate on mechanism body and check
case. Insert idler shaft (44) through case, tapping into
action by slowly rotating top plate. There should be no
place with suitable punch. Place few drops of sealing
side play and fit should permit smooth action.
compound (item 9, table 1-2) on each end of idler shaft.
c. Insert straight end of diaphragm link (16) in slot of
diaphragm centerpiece and secure it with a new pin (15).
2-5. Modification Criteria.
Bend and secure pin so it cannot turn in bearing hole.
Modification criteria is as follows:
Hold diaphragm assembly (46) so link hangs down and
Basic altimeters are modified to a "D"
check action of parts by slowly rocking diaphragm.
configuration by exchanging the old items (16, 17, 18, 20
There should be no play on bearing pin, yet parts should
and 23. fig 2-1) with new parts listed In the I P B and
adjusting the instrument for 35,000 feet instead of 60.000
d. Replace diaphragm assembly (46) in
b. '"D" configuration altimeters are
Change 5 2-8