INSTALLATION INSTRUCTIONS FOR THE REAR DRIVE SYSTEM
For Great Plains Aircraft Rear Drive System

1. THE THREE DRIVE STUDS ARE INSTALLED INTO THE FLYWHEEL WITH THE FLYWHEEL INSTALLED AND TORQUED UP TO THE ENGINE - TORQUE TO 120 FT. LBS. THE DRIVE STUDS WILL STICK THROUGH THE BACK OF THE FLYWHEEL. REMOVE FLYWHEEL AND GRIND OR CUT OFF SLOWLY SO YOU DO NOT GENERATE HEAT. IF YOU HAVE A MIG WELDER YOU CAN PUT A SMALL WELD BEAD ACROSS THE STUDS, BUT IT IS NOT NECESSARY. RE- INSTALL THE FLYWHEEL PROVIDED. YOU WILL HAVE TO RESET THE END PLAY WITH THE NEW FLYWHEEL. IT SHOULD BE BETWEEN .004" AND .006". USE FLYWHEEL GASKET WHEN MEASURING END PLAY. IF YOU HAVE TO CHANGE THE END PLAY, YOU WILL HAVE TO REMOVE THE REAR SEAL TO INSTALL THEM. THE REAR SEAL SHOULD BE REPLACED WITH A NEW ONE IF REMOVED. AFTER SETTING END PLAY, USE 3H PERMETEX AROUND THE ID OF THE FLYWHEEL WHERE IT MEETS THE CRANKSHAFT AND AROUND THE 4 DOWEL PINS ON THE CRANKSHAFT. INSTALL FLYWHEEL AND TORQUE FLYWHEEL GLAND NUT (36MM SOCKET) - TORQUE TO 220 FT LBS. (USE BLUE LOCKTITE ON GLAND NUT.) THIS IS THE MOST IMPORTANT STEP IN SETTING UP THE RDS, SO DO IT RIGHT!

NOTE: 8 DOWEL FLYWHEELS ARE DRILLED FOR LETTER O HOLE SIZE. SOME 8 DOWELS HAVE A LETTER P AND WILL NEED RE-DRILLED.

NOTE: 4 DOWELS ARE ALL THAT ARE NEEDED.

2. INSTALL BUSHING PROVIDED INTO FLYWHEEL GLAND NUT. THE NEEDLE BUSHINGS IN THE GLAND NUT WILL HAVE TO FIRST BE REMOVED. BOLT TORQUE CONVERTER (RUBBER DOUGHNUT) TO DRIVE SHAFT, TORQUING SOCKET SCREWS TO 118 FT. LBS . INSTALL DRIVE SHAFT INTO FLYWHEEL GLAND NUT OVER THE 3 DRIVE LUGS ON THE FLYWHEEL. PUT A LITTLE AXLE GREASE ON THE STUB SHAFT THAT GOES INTO THE FLYWHEEL GLAND NUT AND ADD A LITTLE OIL ON THE THREE STUDS.

3. INSTALL THE BEARING IN THE HOUSING (THERE IS NO FRONT OR BACK). SECURE BEARING WITH BEARING RETAINER AND SCREWS PROVIDED. TORQUE SHOULD BE 9 TO 11 FT. LBS. TAKE HOUSING AND PLACE OVER DRIVE SHAFT. THE ANTI-VIBRATION MOUNTING POINTS ARE AT THE BOTTOM. USE THE 4 BOLTS AND 2 NUTS PROVIDED TO BRING THE HOUSING BACK TO THE ENGINE CASE. TORQUE BOLTS TO 30 FT. LBS.

4. INSTALL THE PROP HUB ON THE END OF THE DRIVE SHAFT. YOU CAN EASILY TELL IF THE FIT IS CORRECT. THE PROP HUB SHOULD NOT SEAT ALL THE WAY FLUSH AT THE START OF THE SPLINE DRIVE. TORQUE NUT TO 110 FT. LBS. INSTALL COTTER KEY. NOTE: IT IS VERY RARE TO HAVE THE COTTER PIN LINE UP EXACTLY WITH THE HOLE IN THE CASTLE NUT. DO NOT OVER TORQUE. REMOVE NUT AND SAND, OR SURFACE GRIND SEVERAL THOUSANDTHS AT A TIME OFF THE WASHER OR NUT. WHEN ALIGNED, INSTALL COTTER PIN AND TRIM PIN.

5. BOLT THE STARTER BOLTS TO THE STARTER PAD WITH THE BOLTS PROVIDED. TORQUE TO 15 FT. LBS. THE STARTER CONTAINS A STARTER SOLENOID AND AN EXTERNAL ONE IS NOT REQUIRED. CONNECT YOUR (+) POSITIVE BATTERY TERMINAL TO THE LARGE POST ON THE STARTER. THE SMALL TERMINAL GOES TO YOUR START SWITCH.

6. IF YOU EVER NEED TO DISASSEMBLE THE TORQUE CONVERTER (RUBBER DOUGHNUT ON DRIVE SHAFT), THE 3 SOCKET HEAD CAP SCREWS ARE NOT REUSABLE. THE TORQUE FOR THESE NUTS IS 120 FT. LBS. THEY HAVE A SPECIAL LOCKING COMPOUND ON THE END OF THEM TO RETAIN THEM IN THE DRIVE SHAFT AND ARE CONSIDERED SINGLE USE ITEMS.

7. WHEN YOU ORDER A PROP, BE SURE TO TELL THE PROP MAKER THAT YOU ARE USING GREAT PLAINS AIRCRAFT REAR DRIVE SYSTEM THAT DRIVES OFF THE FLYWHEEL END OF THE VW ENGINE. ALSO BE SURE TO TELL THEM IF IT IS A PUSHER OR TRACTOR APPLICATION. THE HUB IS THE STANDARD VW PATTERN, 6 EACH 5/16" HOLES, 4" ON CENTER WITH A 2" DIAMETER PROP PILOT THAT IS 1/2" LONG. USE GRADE 5 BOLTS TO ATTACH THE PROP TO THE PROP HUB.

8. THE REAR BRACKET IS SIMPLY DRILLED OUT FOR 10MM SCREWS PROVIDED AND BOLTED TO THE ENGINE. THE ALTERNATOR BOLTS ON TO THE BRACKET. THE PULLEY IS SECURED TO THE ENGINE WITH THE BOLT PROVIDED. TORQUE TO 43 FT. LBS. BECAUSE OF SLIGHT DIFFERENCES IN OIL PUMP COVER PLATES, SOME PLATES REQUIRE A LITTLE METAL REMOVAL FOR THE BRACKET TO FIT AROUND THE OIL PUMP COVER PLATE.

REAR DRIVE TIPS:

The housing is generally heated on the bearing end to ease bearing installation.

The tailstock on the drive shaft is made for both Type 1 and Type 4 installations. For Type 4 installations the length is correct. For Type 1 installation cut off about .250" from the stub shaft. We suggest that you do an actual measurement as each installation will be slightly different. Place the drive shaft stub in the flywheel gland nut and place housing over drive shaft and take a measurement. The flange for the bearing should be about .010" to .030" behind the bearing seat area when you are finished trimming the drive shaft.



IF YOU HAVE ANY QUESTIONS, PLEASE CONTACT US BY E-MAIL AT gpasc@earthlink.net OR 800-922-6507 or 402-493-6507 OR FAX AT 402-493-3846.

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