37-1-614 Page 44
FIGURE 7-11 – DISCHARGE OPENING
FIGURE 7-12 – DIAL INDICATOR
10. Select the correct thickness of aluminum shims (21) to give the shim set established in Step 9.
Check the thickness of the shims with an outside micrometer (FIGURE 7-10, page 43). Place the
shims on the end of the housing, matching the pointed section of the shims with the contour of
the housing. Remove bearing spacers from the discharge end bearing carrier, (FIGURE 7-7,
page 42). Apply Loctite 620 to the I.D. of the bearing spacer. Place them over the shaft
extensions grooved end toward rotor. Be sure the spacer fits solidly against the rotor. If
measurements in Step 8 differ, make sure the bearing spacer is placed over its respective shaft
extension to assure proper end clearance of each rotor.
11. Coat the I.D. of the shaft seals (18, 19) in the discharge end bearing carrier with oil. Remove
bearings from the carrier. Tag bearings so they will be reassembled in the same bearing bore
from which the measurement was made. Match the cavity of the carrier, (FIGURE 7-7, page 42),
with the discharge opening of the housing (FIGURE 7-11), and lower the carrier, suspended
plumb, in place on the housing. Be careful not to damage I.D. of the shaft seal by the shaft
extension. Be sure there are no shaft shims in place during this operation as sharp edges of
shims will damage the seals. Tighten the carrier to housing screws (47, 59) evenly to prevent
damage to dowel pins.
12. With the dial indicator attached as shown in (FIGURE 7-12), check the total end clearance. Set
the indicator on zero and lift the rotor with a hoist until the end of the rotor strikes the face of the
discharge end bearing carrier. The reading of the indicator will be the total end clearance and
should match dimensions listed in the clearance chart, (FIGURE 7-8, page 43). If the indicator
reading differs from the chart and allowable tolerance, repeat Step 9 and 10 as well as check for
burrs giving false readings.
NOTICE
Due to allowable machining tolerance of the rotor lengths, there may be cases where one
rotor will be within limits and the other slightly over or under.
13. All internal oil seals are uni-directional lip seals. They must be installed in the correct location
and with proper orientation or the oil will be pumped out of the sump, not retained in it. The
rotation arrows (stamped on the face of each seal) and the letters for clockwise (CW) rotation or
for counterclockwise (CCW) rotation are located on the air side not the oil side, of the seal case.
These seals have also been color coded so that the seals with the green outside diameter are
always for counterclockwise rotation and the seals with red outside diameter are always for
clockwise rotation, when viewed from the air side of the seal. The gate rotor seal on the gear end
will always be green so if you think of the three
G’s
G
ate,
G
ear and
G
reen, you will always know
where one seal gets installed. After that, the other rotor on the same end has to be of opposite
rotation so the main rotor on the gear end would be a red seal. Since the rotation, viewed from
the ends of the rotor, must be different from end to end, the inner seal on the discharge end of
the main rotor would be green and the seal on the discharge end of the gate rotor would have a
red outside diameter. Each of the seals has a dirt lip on the air side which does not have any
spiral grooves in the lip. See (FIGURE 7-13, page 45), for installation guidelines.
