37-1-615 Page 49
32. Hold the gear and shaft from turning and evenly tighten five gear to hub
“Nylock” type screws (48)
(FIGURE 7-31). Tighten screws to 100-110 ft-lbs. Be sure the indicator reading does not change
while tightening the screws. The rotors are held in time by the clamping action of the screws and
distortion of the flat washers into the gear holes. Check interlobe clearance to make sure the 2/3
indicator reading is on the discharge side.
Discharge side clearance is checked with a feeler gauge through the discharge opening in the
housing. Rotate the blower several times to be sure timing has not slipped. Recheck the discharge
side interlobe clearance and discharge end clearance. When timing is completed remove the
indicator, button bracket and gear hub retainer plate. Install the hub retainer plate (13) with pilot in
the hub bore with three
“Nylok” type screws (49). Tighten screws to 118-140 ft-lbs. Install the gasket
(24) and carrier cover plate (15) with lockwashers (54) & screws (52). Tighten screws to 38-41 ft-lb
in a star pattern making at least two passes. Install breathers (38) on bearing carriers (4, 5) Note: It
is recommended to apply a thin coat of Dow Corning 736 sealant on each side of gasket (24) prior to
installation.
Referring to
“Lubrication”, page 25, fill the carriers with proper oil to the middle of the sight gauge.
Cover all openings to prevent dirt entering the blower during transportation and installation.
If the blower is to be stored, refer to
“Storage,” page 9.