Revision 1.8 / June 2016
12
Power End Disassembly, cont.
3. Remove the bearing housing mounting cap screws, item 640, which connect the bearing housing,
item 700, to the power frame, item 600. The bearing housing may then be removed by pulling the
shaft, item 200, and bearing housing away from the power frame.
NOTE: Be sure to support the
bearing housing such that the shaft will not be damaged when pulling it through the hole in
the power frame.
4. Remove the shims, item 800, which are located where the bearing housing meets the power
frame.
5. Remove the bearing housing cover cap screws, item 768, which connect the bearing housing
cover, item 760, to the bearing housing. The bearing housing cover can then be removed.
6.
Using a punch and hammer or a press, remove the outboard oil seal, item 742, from the cover.
NOTE: Be careful not to damage the bearing housing cover when removing the seal.
7. Loosen the four small set screws located in the bearing locknut, item 750. The bearing locknut can
then be unscrewed and removed from the shaft.
8.
Using a press, remove the shaft from the bearing housing by applying force to the key end of the
shaft. As the shaft is being forced out of the bearing housing, the rear tapered roller bearing inner
race, item 770 (MR150: item 771), is being removed from the shaft.
NOTE: The shaft will come
free and drop out of the bearing housing when the bearing is pressed out. Be sure to
support the shaft such that it will not be damaged.
9. Remove the inboard oil seal, item 741, by simply pulling it off of the shaft.
10. Remove the front tapered roller bearing inner race, item 770, by pressing the bearing off of the
shaft.
11. Using a punch and hammer or a press, remove the front and rear tapered roller bearing outer
races, item 770, from the bearing housing.
NOTE: Be careful not to damage the internal
diameter of the bearing housing when removing the outer races.
Power End Assembly
1. Press the front and rear tapered roller bearing outer races, item 770, into the bearing housing,
item 700, being sure that the angled ends of the races face out of the housing. In the case of the
MR-150 and MR-150RF, the larger of the two outer races, item 770, should be pressed into the
flanged end of the bearing housing.
NOTE: Be careful not to damage the race surfaces, as this
may lead to premature bearing failure.
2. For easy bearing assembly, lock the shaft, item 200, into a vertical position with the key end of the
shaft on top. Heat one of the tapered roller bearing inner races (in the case of the MR-150 and
MR-150RF, the larger of the two bearings), item 770, to a temperature of 250°F. Thermal
expansion of the bearing will allow it to fit into the shaft.
NOTE: Do not overheat the inner race,
as this will distort the roller support. While the bearing is hot, fit it onto the shaft until it
reaches the step, with the tapered section facing upward.
3. Place the bearing housing, item 700, flanged section first, over the shaft. This will seat the front
bearing inner and outer races.
4. Heat the other tapered roller bearing inner race, item 770 (in case of the MR-150 and MR150RF,
item 771), to a temperature of 250°F. While the bearing is hot, place it onto the shaft with the
tapered section facing down into the bearing housing. This will seat the back bearing inner and
outer races.
