Flap Motor Grease Removal
Good Morning,
There has been a number of instances of Van’s flap motor quitting as a result of the lubricating grease getting into the motor housing and gumming up the brushes. This causes the motor to fail. Pilots have had the motor fail in all positions. This can be an awkward situation that tends to present itself either in the beginning of your flight or at the end. I think that it would be most dangerous during a missed approach where you need to get the flaps up to achieve a positive rate of climb on the overshoot.
My friend Gary Wilcox just posted a great article on vansairforce.net that shows how to take the motor and linear actuator apart to remove the excess grease. I will re-post his article below.
Build Smart and Fly Safe
Dave
Once again I find my flap motor not wanting to go down, oh well, better than not going up after take off. I had cleaned the shaft of the motor before, but did not fully disassemble the unit to clean it out of grease. So, out to the hanger I go to resolve this issue with hopefully a better result than the last time, it lasted 45 hours. First remove the flap assembly from the plane, hard to see in this pic, but there is quite a bit of grease on the shaft. Some is good, but this was to much.
Remove the two screws from the top of the motor.
Gently pry off the motor cap.
Pull off center body that has the magnets. You can see on the top of the motor where the brushes contact the shaft, all gummed up with oily goop.
Remove two Allen screws from bottom of housing and remove screw unit.
The larger hole was full of grease, this is what works up into the motor to stop the brushes from working properly. Clean out the excess grease.
Clean off as much grease as you can, but be sure to leave some on the shaft that comes out of the housing and attaches to your flap weldment. Also, there are tiny bearings at each end of the motor, don’t put anything in them to remove the grease in them. Clean off the ends of the brushes and shaft where the brushes touch. I used a light touch with a Scothbrite pad. Assemble the unit, putting a drop of Lock-Tite on the Allen screws (was on them when removed) and be careful not to bend the little springs that hold pressure on the brushes. People have different ways to hold these in when reassembling, I just used my fingers, no big deal. Re-install and test. Mine worked fine. Hopefully, by doing the full grease removal it will last a long time.
Best part, it was only an hour job, start to finish.
This was how I did this fix and in no way am an expert. This info is worth what you paid for it. Use it wisely. Your mileage may vary.
Gary