Installation of Thrust Bearings
The Model 3500XD utilizes a thrust bearing on the coupling end of the shaft designed for high unidirec-
tional thrust loads. It is thus critical that the thrust bearing be installed in the proper orientation. The "S"
and "L" group pumps utilize a four point contact bearing paired with a standard angular contact bearing.
The "M" group pump utilizes a Pumpac pair of bearings. Refer to bearing chart in Figure 24 for detailed
bearing designations.
Both types of thrust bearings consist of a matched pair of bearings with an arrow scribed on the outer
races (see Figures 26 & 27). The arrow must point in the direction of axial thrust (i.e. towards the cou-
pling end of the shaft). An arrow attached to the top of the bearing frame (Figures 26 & 27) shows the
correct thrust direction.
Figure 26:
6.5 Reassembly of pump
3500XD Installation, Operation and Maintenance Instructions
43
