Finish Thompson DB11 series Assembly, Installation And Operation Manual page 12

Check the impeller thrust ring and bushing for wear. See
figure 16.
Figure 16
6. Remove the impeller shaft (item 6) from the barrier and
check for signs of cracking, chipping, scoring or wear.
See figure 17.
Figure 17
7. Remove the barrier (item 7) from the motor adapter (item
8). Make sure the spindle has been removed. Pry the
barrier out with your hand. Inspect the inside and outside
of the barrier for signs of rubbing. See figure 18.
Figure 18
8. Remove the o-ring (item 2) from the barrier and inspect for
chemical attack, swelling, brittleness, cuts, etc.
9. Visually inspect the outer drive (item 9) for rubbing,
damage, corrosion or loose magnets.
Outer Drive Replacement
1. Remove the setscrews (item 9A) from the side of the
drive (NEMA motors) or the bolt, lock washer and flat
washer (items 18, 19, 20) from the center of the drive
(metric motors).
WARNING: Be careful, tools will want to be attracted to
the magnets.
2. Remove the drive magnet from the motor shaft by gently
prying up from the bottom of the drive. See figure 19.
3. To reinstall the drive or a new drive follow the instructions
from Section I - Assembly, Pumps without Motors, steps
4-6.
Thrust Ring Replacement
1. Thrust ring (item 4A) is held in-place with a snap fit with a
ridge. Using a razor knife or side cutters, cut a notch out of
the thrust ring. Pull ring up and out of the holder. See
figures 20-21.
Figure 20
2. To reinstall, align the two flats on the thrust ring with the
flats in the bore of the impeller. Using a piece of wood,
press into place using an arbor press until the thrust ring is
completely seated in the impeller.
Bushing Replacement
1. To remove the bushing, place the impeller/inner drive
assembly in an arbor press. Insert a 3/4" diameter plastic
or wood shaft through the eye of the impeller and press
the bushing out.
2. To replace the bushing (item 5A), place the top of the
impeller on an arbor press with the thrust ring face down.
Insert the front of the bushing (figure 22) into the center
of the impeller/inner drive magnet assembly, aligning the
flat on the bushing with the flat in the bore of the inner
drive magnet. Using a soft arbor, press into place until the
bushing reaches the shoulder molded into the inner drive
(figures 23 and 24).
Figure 22
12
Figure 19
Figure 21
Figure 23 Figure 24