Gorman-Rupp Pumps U4A60S-B 1289519 and up - Manual (Page 31)

OM-05665 SUPER U SERIES
MAINTENANCE & REPAIR PAGE E - 7
Remove the back cover nuts (22) and pry the back
cover and assembled wear plate from the pump
casing (1).
NOTE
An alternate method of removing the back cover
from the pump casing is to remove the back cover
nuts (22) and two diagonally opposing locking col­
lars (21). Install two 1/2-13 UNC2B x 2 inch long
screws in the tapped holes in the back cover and
use them to press the back cover out of the pump
casing.
Inspect the back cover and wear plate O‐rings (15
and 19) and replace them if damaged or worn.
Inspect the wear plate and replace it if badly scored
or worn. To remove the wear plate, disengage the
hardware (17 and 18). Remove the O‐ring (16) from
the groove in the wear plate.
Rotating Assembly Removal
(Figure 2)
The rotating assembly may be serviced without
disconnecting the suction or discharge piping;
however, the power source must be removed to
provide clearance.
The impeller (1) should be loosened while the rotat­
ing assembly is still secured to the pump casing.
Before loosening the impeller, remove the seal cav­
ity drain plug (20) and drain the seal lubricant. This
will prevent the oil in the seal cavity from escaping
when the impeller is loosened. Clean and reinstall
the seal cavity drain plug.
Immobilize the impeller by wedging a block of
wood between the vanes and the pump casing,
and remove the impeller capscrew and washer (27
and 28).
Install the shaft key (17). Install a lathe dog on the
drive end of the shaft (22) with the “V” notch posi­
tioned over the shaft key.
With the impeller rotation still blocked, see Figure 3
and use a long piece of heavy bar stock to pry
against the arm of the lathe dog in a counterclock­
wise direction (when facing the drive end of the
shaft). Use caution not to damage the shaft or key­
way. When the impeller breaks loose, remove the
lathe dog, key and wood block.
NOTE
Do not remove the impeller until the rotating assem­
bly has been removed from the pump casing.
Turn
Counterclockwise
Lathe Dog Arm
“V” Notch
Shaft Key
Impeller
Shaft
Lathe Dog
Setscrew
Heavy
Bar Stock
Figure 3. Loosening Impeller
(Figure 1)
Remove the hardware (10 and 11) securing the ro­
tating assembly to the pump casing. Separate the
rotating assembly by pulling straight away from the
pump casing. Tie and tag the rotating assembly
adjusting shims (12) for ease of reassembly.
NOTE
An optional disassembly tool is available from the
factory. If the tool is used, follow the instructions