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1. Clean and degrease the
crankshaft end and mounting holes on the crankcase before
starting.
2. Using the Rotax fixation
tool supplied in the Rotax tool kit lock the engine up by
installing the pin into the impulse hole, used to run the fuel
pump. With the pin in place rotate the engine, until it locks.
3. Install drive gear onto
crankshaft end, with the lockwasher under the head of the
bolt, and the flat washer under the lockwasher. Torque to 45
FOOT lbs.
4. Install the rubber O ring
(#3) into the back half of the gearbox adapter plate, if
necessary use dielectric grease to hold ring in place.
5. Position back half of
gearbox (#1) onto crankcase. Apply loctite #242 to threads of
bolts (#4) install 4 allen bolts bolts and torque 30 FOOT lbs.
6. Install the rubber O ring
(#3) into the front half of the gearbox adapter plate, if
necessary use dielectric grease to hold ring in place.
7. Install back half of gear
box housing.
8.Install gasket - make sure
gasket is not damaged.
9. Install front half of gear
box housing and secure with bolts/nuts and lockwashers. Use
loctite 242 on threads and torque to 195 INCH lbs.
10. Fill gear box with 90
weight oil until oil runs out the lower of the two side plugs.
11. Tighten then safety wire
top and bottom plugs.
12. Tighten then safety wire
vent cap and drain plug.
Rotax A Gear
box updates:
Updated - Rotax gear, dog
hub, washers, shaft.
Aircraft: All ultralight aircraft using
the Rotax reduction drive.
Incident report:
We have several reported problems from
pilots using the Rotax reduction drive.
1. a hard to start engine, or an engine that will start but
has a hard time coming off an idle or runs very erratic at
idle.
2. the gears inside the gear box disintegrating, especially on
engines using large radius propellers.
3. the gear box retaining bolts vibrating loose and or
breaking allowing the gear box to in one case come right off
the back of the engine.
4. the output shafts on the gear box especially on the 65 hp
engines, severing, or the prop shaft hub cracking.
5. the oil slinger located on the end of the output shaft
breaking and then getting messed into the gears.
6. the loss of reduction drive gear oil during flight.
7. the stripping of the bolts used to attach the prop to the
hub of the gear drive.
Suggestions:
1. There was a problem on early Rotax gear
drives where a series of spring washers inside the gear box,
over a period of time lost their tension.
This in turn caused the engine to become hard to start, and
would not come off an idle. Rotax has an update kit which
replaces the eight spring washes, and spacers found in the old
style gear drives with a new 12 spring washer system.
It is recommended that these spring washers be replaced every
150 to 200 hours and that the gear drive oil be checked
periodically, and replaced every 100 hours or yearly which
ever comes first.
2. The problem with the gears shattering was also an early
problem, and there is also a retrofit kit, which replaces the
gear with a stronger gear.
3. The problem with the retaining bolts backing off was more
common on the 3 bolt pattern adapter plates, the new engines
are 4 bolt. This problem was also caused by pilots who were
reinstalling the gear box for whatever reason.
In reinstalling the bolts on the 3 bolt
system, there are two different lengths of bolts. Both bolts
will go in and appear to tighten the plate against the
housings. In fact the longer bolt is bottoming out in the
crankcase housing and is NOT tightening up on the adapter
plate.
4. The aluminum hub cracking hub cracking problem were also
corrected on later model Rotax reduction drives, I am not
however aware of a retrofit kit for this at this time. The
only suggestion would be to update to the new style steel
output shaft and hub.
5. The oil slinger problem has been eliminated by the removal
of the slinger completely. New model engines do not come with
the oil slinger, and the removal of them is recommended on
older style gear drives.
6. The stripping of the prop bolts seems to occur when pilots
have taken off and reinstalled their props several times. Some
pilot have reported drilling out the holds using larger bolts,
with locking nuts, and safety wire.
Other pilots have simply gone to larger
bolts and used the other bolt pattern on the redrive. This
problem is caused by the pilot over torquing the prop bolts on
installation. The recommended torque is 100 INCH LBS.
7. The gear oil existing problem can be cured simply by
installing a very small gas line filter on the top of the
reduction drive vent cap using a small piece of gas line and
some clamps. It is caused by the prop creating a low pressure
area above the vent, siphoning the oil out of the gear drive.
Rotax Engine Rebuilding Videos
Rotax engine rebuilding videos, each video is approximately 2
hours in length and takes you step by step through the tear
down, clearing, and reassembly of a Rotax engine
Click here for more information!
Click here for proper A and B box preload
procedure
Click here for gear box installation in pdf format
Rotax gear box updates - click here for more
information
Rotax manuals in pdf format
Rotax 2 stroke installation manual
Rotax 2 stroke maintenance manual
Rotax 2 stroke operators manual |
