Revision 1.8 / June 2016
13
Power End Assembly, cont.
5. With the bearing still hot, tighten the bearing locknut, item 750, onto the shaft, only enough to
eliminate any float between the shaft and the bearing housing.
NOTE: The holes for the set
screws must be facing upward or out of the bearing housing when the bearing locknut is
installed. While tightening the bearing locknut, rotate the bearing housing a few times to
insure that the bearings have seated properly.
6.
After allowing the assembly to cool, tighten the bearing locknut until the torque required to turn the
shaft falls within the following range of your specific pump model:
MR-120 and MR-125
=
1 to 3 in lbs
MR-130 and MR-135 and MR-135RF =
6 to 8 in lbs
MR-150 and MR-150RF
=
8 to 10 in lbs
This requires tightening the shaft nut, item 231, onto the shaft, item 200, and using a torque
wrench to measure the torque required to turn the shaft.
NOTE: Remember, this is the torque
required to turn the shaft. The actual torque required to turn the bearing locknut is much
greater.
7. Tighten the four set screws on the bearing locknut.
8. Press the outboard oil seal, item 742, into the bearing housing cover, item 760, with the lip section
of the seal facing outward. Be sure to lubricate the inner and outer diameter of the lip seal.
9. Apply a quality gasket sealant to the mating surface of the bearing housing cover, item 760, and
the bearing housing, item 700. Fit the bearing housing cover onto the bearing housing while lining
up the holes for the bearing housing cover cap screws, item 768. Fit the bearing housing cover
cap screws into the holes and tighten to the torque specification provided on page 28.
10. Press the inboard oil seal, item 741, into the bearing housing by fitting it, lip section first, over the
wet end of the shaft. Be sure to lubricate the inner and outer diameter of the lip seal.
11. Clean the mating surfaces between the bearing housing, item 700, and the power frame, item 600,
to insure that no debris is between the parts. Fit the bearing housing onto the power frame while
lining up the holes for the bearing housing mounting cap screws, item 640. The bearing housing
must be oriented such that the drain plug, item 737, is located at the bottom.
NOTE: Be sure to
support the bearing housing such that the shaft will not be damaged while fitting it through
the hole in the power frame. Fit the bearing housing mounting cap screws into the holes
and tighten to the torque specification provided on page 28.
12. Install and tighten the drain plug, item 737.
13. Remove the oil fill plug and oil level plug, items 737. Fill the bearing housing with oil until the oil is
visible through the level hole. Refer to page 23 for oil lubrication recommendations.
NOTE: Fill
the bearing housing with oil only to the oil level hole, as overfilling may cause the bearings
to fail prematurely. Replace and tighten the oil fill and oil level plugs.
14. Before replacing the parts in the wet end of the pump, refer to page19 for shimming instructions.
NOTE: The bearing housing must always be shimmed when the bearings are changed or
the bearing housing is removed for the purpose of properly locating the rotor in the center
of the pump
.
