Duff-Norton SK6420-6 - Manual (Page 10)

f. Assemble motor (53) into housing (42) . Before
assembling lock washers (46) and socket head
screws (45), hold motor firmly in place and, with
a screwdriver, turn motor shaft by using
screwdriver slot in end of motor shaft.
NOTE
Before turning motor shaft, make sure pinion shaft has not
been pushed out. It may be necessary to hold pinion shaft
down while turning motor shaft. If couplings are properly
installed, the motor can be turned freely in both directions. If
motor shaft will not turn, this is an indication that couplings
are not properly aligned and assembly should be corrected.
g. Install lock washers (46) and socket head
screws (45).
h. Replace hole plug (54) in end of motor.
34. Insert dowel pins (27) in housing (42) and place
gasket (41) in place over dowel pins (27).
35. Install air vent (58) in outer tube (55) ( it may be
necessary to back outer tube out in order to
install air vent or to have vent in a more
desireable position). Spot drill through threaded
holes in housing (42) and outer tube (55) into
adapter (63) and install set screws (38).
36. Install spring (61) into end of screw (62).
NOTE
If unit has potentiometer assembly (26) and gear (26b) does
not have to be replaced or if unit has no potentiometer
feature, proceed to Step 37.
37. Potentiometer Assembly (26)
a. If nut and washer were removed from
potentiometer, assemble washer (26d) and nut
(26c) on potentiometer (26a). Nut (26) on
potentiometer (26a). Nut (26c) should not be
tightened on potentiometer (26a) face.
b. Assemble gear (26b) on potentiometer (26a)
shaft.
NOTE
Gear should be assembled with a very light press. See
sketch for required dimension of gear on potentiometer.
Take care not to damage potentiometer.
dia. pins approximately 1-1/2" long. One pin
should drop into hole in output gear (39). If pin
does not drop into hole, tighten or loosen
spacer nut until hole is aligned and one pin
drops into hole. (Note: spacer nut should not be
rotated more than 22-1/2 degrees before pin
drops into hole in gear.) It is preferable to
tighten spacer nut down instead of loosening.
27. Remove pin from aligned hole. Install half dog set
screw (68) and tighten half dog point into hole
in output gear (39). Remove remaining pin and
proceed with assembly. Note: One hole must be
in alignment to have proper assembly.
28. Apply generous amount of Exxon Ronnex Extra Duty
#1 (no substitutes) to thrust washers (35) and
thrust bearing (36) and assemble over spacer
nut (37).
29. Lightly grease O.D. of translating tube (66) with
Exxon Ronnex Extra Duty #1 (no substitutes)
and assemble outer tube (55) assembly over
translating tube (66) and thread onto adapter
(63) (a sealing compound such as Non-
Hardening Permatex 2 should be used on
threads).
30. Insert intermediate pinion shaft (32) in housing (42)
and place thrust washer (31) over shaft (32).
Assemble intermediate cluster gear (33) on shaft
and place thrust washer (31) on top.
31. Assemble bearing (28) on input pinion (29) (press on
inner bearing ring to prevent damage to
bearing).
32. Pack housing (42) gear box cavity with Exxon
Ronnex Extra Duty #1 (no substitutes).
33. Assembly of Motor (53) to Housing (42)
a. Note location of flat on input pinion by
marking spot on the housing. See Figure 6-1B.
b. Insert grommet (50) on input pinion (29)
between coupling (47) posts and install “O”-
Ring (52) in cavity of insert (51).
c. Pack cavity with Exxon Ronnex Extra Duty
#1.
d. Remove hole plug (54) in rear end of motor
e. Feed motor (53) lead wires through hole in
housing (42) lining up couplings (47) on input
pinion (29) and motor (53) shaft. (Alignment is
critical at this point. See Figure 6-1B.)
NOTE
Input pinion (29) and motor (53) shaft flats are opposite
each other.
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DN-SK6420-6-1006 10/10/06 11:40 AM Page 10