3
4. Remove square housing (4), ring gear (12), pinion gear (11) and key (13) from shaft (6). Do not permit dowel
pin (37) to drop as housing (4) is removed. Remove dowel pin (37) from square housing (4), front cover (1), or
back of round housing (3) whichever is applicable.
NOTE:
If square gear housing (4) will not slide easily off shaft (6) and pump is a one stage unit, clamp
square housing (4) in a vise with front cover (1) free. With a soft headed hammer, tap alternately on
mounting ears of front cover (1) until there is sufficient gap to insert a wedging device. Pry gap until
square housing (4) is free to slide off shaft (6). If pump has more than one stage, clamp pump in a vise
with square housing (4) free. With a soft headed hammer, tap alternately on edges of square housing
(4) to separate it from round housing (3) until there is sufficient gap between the square (4) and
round (3) housings to insert a wedging device. Pry gap until square housing (4) is free to slide off
shaft (6).
CAUTION
ATTENTION
Take care not to damage either faces that are being pried against or 0-ring (41) with prying device.
CAUTION
ATTENTION
If gear housing (4) did not slide off easily because its bushing (53) was jammed on shaft (6), ball
bearing (31) was most likely damaged when housing (4) was pried off and it must be replaced.
Alternately, if gear housing (4) will not slide off easily because its rabbet was jammed in counter
bore of barrel (8) or front cover (1), whichever is applicable, ball bearing (31) may not have to be
replaced.
NOTE:
If housing (4), ring gear (12) or pinion gear (11) cannot be removed without applying excessive force,
pump should be returned to Imo for further disassembly and inspection.
5. If unit has only one stage, proceed to step #9. If pump has more than one stage, continue with step #6.
6. Remove housing tube (8). Remove O-rings (41) from counter bores of square housing (4) and round housing (3).
NOTE:
Neither housing tube (8) nor O-ring (41) need be removed from round housing (3) unless O-rings (41) are
to be replaced. (Replacing O-rings is good practice when a pump is disassembled after extended service
or if damaged during disassembly.)
CAUTION
ATTENTION
In next step, ring gear (12), pinion (11) and key (13) will be removed. If ring (12) and pinion
(11) are to be reused, identify them, with a marker or the like, so it can be determined
to which housing they belong (if there is more than one housing in pump) and which
direction face of each gear was positioned in housing. Do not mark with scribe or punch
as this may leave a burr or high spot which could lead to pump damage or seizure. If key
(13) is to be reused, mark it so that it can be assembled into its original stage and facing
its original direction.
7.
Remove round housing (3), ring gear (12), pinion gear (11) and key (13) from shaft (6). Do not permit dowel pin
(37) to drop as round housing (3) is removed. Remove dowel pin (37) from either round housing (3) or front
cover (1) whichever is applicable.
CAUTION
ATTENTION
In next step, ring gear (12), pinion (11) and key (13) will be removed. If ring (12) and pinion (11) are
to be reused, identify them, with a marker or the like, so it can be determined to which housing
they belong (if there is more than one housing in pump) and which direction face of each gear
was positioned in housing. Do not mark with scribe or punch as this may leave a burr or high spot
which could lead to pump damage or seizure. If key (13) is to be reused, mark it so that it can be
assembled into its original stage and facing its original direction.
