VG-21 Squadron



MAINTENANCE ITEM #31 - Newsletter #59

(by Lee Beery)
Recently, during our aircraft annual, I disassembled, cleaned and inspected the nose gear assembly. I then replaced the 0-rings (2) and installed a new oil seal. (See Maintenance Item #23.) I then installed the correct amount of hydraulic oil and reinstalled the assembly. Then I added the bearings lubricating oil (I use chain saw “bar” lube). Before I reinstalled the screw in the bearing lubrication port of the outer cylinder, I removed the nose gear support. With the aircraft weight now on all three gears, I pulled down and pushed up on the propeller to cycle the nose gear to achieve maximum travel. When I did this, I could hear rushing in and out of the lubrication port.

I explained all of this to Max Bishop and we think we may now know what it is so hard to keep that lubrication oil in the gear assemblies. When the aircraft becomes airborne, the springs extend the gears, increasing the air capacity of the assembly. The easy route for the air to enter is past the oil seal. When the aircraft lands, the air in the cylinder is compressed and with oil sitting on top of the oil seal when the air is forced out past the oil seal, it takes some oil with it.
This is just a theory but I am in the process of testing this theory and will report my findings in future newsletters.