Propeller Gearbox - Rotax MMH-912 Series Maintenance Manual

3.9)

Propeller gearbox

See Figs. 72-20, 72-20/1 and 72-21.
Before removing the gearbox, it is advisable to check the friction torque. See the
corresponding Maintenance Manual (Line Maintenance) for the respective
engine type, 912 Series or 914 Series.
■ CAUTION : When removing the gearbox, take care not to damage the
Lock crankshaft. See chapter 12-00-00 of the maintenance manual (line
maintenance) of the corresponding engine type (912 Series or 914 Series).
Remove 8 allen screws (1) M6 and 2 allen screws (2) M8 together with the lock
washers crosswise from the gear cover (3). The gear cover is kept in position
by 2 dowel pins. Screw puller (4), part no. 877660, into the two M8 mounting lugs
(5) of the gear cover (3). Now the complete gearbox can be pulled off with the
slide hammer puller (6) without damaging the ball bearing and the propeller
shaft.
◆ NOTE:
Insert dowel pin 8x20 (7) into the right (8) and left (8) bore of the gearbox
housing. Screw hex. screw M6 x 40 into the release mechanism. Center the
release mechanism (10) and tighten with hex. screw M10x20 (11). Turn left and
right hex. screws (9) evenly to press the gearbox housing off the crankcase.
▲ WARNING: Heated up components - Risk of scalds and burns. Wear safety
Use a hot air gun to heat up hex. nut M30x1.5 to about 100 to 120 °C ( 212 to 248
°F).
Release hex. nut M30x1.5 (12) with wrench 41 a/f, part no. 877445 and remove
the drive gear with friction washer (13) from the crankshaft. If required, lever
drive gear gently off with 2 screwdrivers.
◆ NOTE:
Make sure that both dowel sleeves remain in the crankcase and not in the
gearbox housing.
■ CAUTION : The gear set has a continuous 6-digit serial number which is
Effectivity 912/914 Series
Edition 1 / Rev. 3
BRP-Powertrain
Maintenance Manual
bearing seat and the oil seal running surface of the propeller
shaft.
Alternatively the optimized special tool part no. 877540 can be
used to remove the propeller gearbox. See Fig.
gloves!
Hex. nut has lefthanded thread!
shown on the front side of the drive gear (14) and on the dog
gear. The gears are paired as a set and must not be exchanged
individually.
72-20/1.
72-00-00
page 22
October 01/2010