Control Tube Panel Bushings

[wa4jr]

On a recent flight I noticed that the elevators were binding...so much so that landing the aircraft was not very easy. All sorts of horrible pictures of frayed/stretching cables and frozen pulleys were going through my mind when I had an idea. I looked at the control tubes going through the panel bushings and found them to be bone dry with track marks of some black material. I sprayed each tube with a good coat of WD-40 wiped the tubes down, cleaning away the track marks and then reapplied a light coat of WD-40. That did the trick! All the binding was in the teflon/nylon ball bushings. I thought these were suppose to never need lubrication? Wonder what other folks have applied to their tubes to keep them lubricated through the bushings. WD-40 does not last very long.

[logsdon]

At each annual inspection I clean the tubes and apply a light coating of white lithium grease.

[mschlender]

Are you sure that the balls are able to float in the housings? Mike

[n1410d]

I had the same problem with my bushings several years ago. Wag Aero sells the bushings. If your bushings are white in color then they are the new type. I think the orgional bushings were black or graphite in color. Also make sure that the bushings can float inside the panel. When I installed my new bushings I put a washer between the socket and the panel. With the control shaft removed you should be able to move the bushings with your finger and feel just a slight amount of resistance from the panel. I use food grade silicone grease on my control shaft to keep things slippery. Why food grade silicone?? It doesn't collect dirt very easily, it doesn't stain if you get it on you, and it works well. You can get it at a SCUBA shop or sporting goods store.
Be careful on your first flight after you install those bushings. My elevators were so sesitive that I was porposing all over the sky for the first few minutes.

Patrick Mahaffey
C170A
N1410D
Grand Prairie, TX (Across from Joe)

[wa4jr]

Yes, my balls are floating....er the round bushings are indeed floating in the panel fixings. I have the white bushings, but I suppose nobody ever bothered to lube the tubes during annuals and they finally began to bind. Thanks for all the tips fellas!

[flyguy]

OOOHH BOY SUMA YOU GUYS IS GONNA GIT AXTRIXED!

No, I wont go on with that. The white bushings are teflon and should be free as a w... in dec. Oh heck I have a hard time resisting such opportunities.....

The original bushings were phenolic and over the years absorbed dust and moisture causing binding both on the inside and outside. The newly manufactured "white" bushings are "Teflon" material and should not need any additional lube. If there is stiffness in the movement it usually indicates binding balls ........