Vibration on Landing

[bakerde36]

About 3 hours/landings ago I started getting bad vibration/shaking on landings and doesn't stop until I get about taxing speed. This just started so I am not sure what to look for.
Thanks for any info Densil

[kmacht]

Tail wheel or tri-gear, how many hours on the plane, and is the vibration immediately upon touching down with two wheels or only after all 3 are on the ground?

If you have a bunch of hours, one place to look is at the axle/gear leg intersection. I know a few higher time Sonex that wallowed out the bolt hole in the axle tubing. The fix was to just weld a washer to the outside of the axle to give the bolt some more meat to rub against.

Keith
#554

[bakerde36]

I have around 24 hours and it started a few landings ago, I will check the bolts tonight. It seems to happen after I have all three wheels on the ground almost immediately.
Thanks for your help

[mike.smith]

Does it happen when braking, of does it happen even if you are not applying any brakes?

[fastj22]

I have around 24 hours and it started a few landings ago, I will check the bolts tonight. It seems to happen after I have all three wheels on the ground almost immediately.
Thanks for your help

Check your wheel bearing races. Chances are you didn't get them seated properly and they have moved. My guess is your bearings are a bit slacked.

[mike.smith]

I have around 24 hours and it started a few landings ago, I will check the bolts tonight. It seems to happen after I have all three wheels on the ground almost immediately.
Thanks for your help

Check your wheel bearing races. Chances are you didn't get them seated properly and they have moved. My guess is your bearings are a bit slacked.

That's a possibility. The bearings need to be seated further than you might think.

This was my first post (see the top photo). Note the gap between the wheel and the dust cover, exposing some of the bearing. This is wrong!
http://www.mykitlog.com/users/display_l ... 665&row=59

See the top photos here. Note the dust cover is flush with the wheel and you cannot see any of the bearings.
http://www.mykitlog.com/users/display_l ... 85&row=617

[NWade]

Note: The wheel bearings are slightly different now - I found this out when my Aerobrakes didn't fit quite right. Sonex quietly changed over to selling wheel bearings with an integral rubber cover. If you use the metal dust-cover on top of that, the bearings will stick out beyond the sides of the wheel, even with the bearing races fully seated.

Fun fact: the AeroBrakes assume that you are using these newer style of bearings, that stick out further! If you don't Use them, there will be a gap between the brake body and the wheel bearing that may allow the wheel to move slightly (which could account for some shimmy/wobble).

Which is not to say you shouldn't check the races! Give them a few raps and see if they "ring" and don't move. Just don't beat the snot out of them if they don't wind up looking exactly like Mike's photo (which I believe are the older bearings without the integral rubber seal).

--Noel

[Jim B]

I developed a bad shimmy/vibration on my plane both on take off and landing. It turned out to be I had worn my tires out. I put new tires and tubes on and the shimmy/vibration was gone.
Jim

[bakerde36]

I have also worn out my tires new tires on the way and I will check the bearings. It is a tail wheel and only happens on landings. Thanks everybody for the things to check

[jeff0196]

My kit came with the non-sealed wheel bearings that have the metal dust cover ring. I too found that the races were not installed all the way into the wheels how I received them. I pressed the races in until fully seated in the wheels when assembling them for the first time. The metal dust cover lined up with the outside of the wheel how it should (Completely flush - I used a bearing/seal driver and a hydraulic press-worked great!). I later bought from Sonex the rubber sealed bearings. They still instructed me to use the metal dust covers on the outside of the rubber sealed bearings. They might sit just slightly wider then the non-sealed bearings, but just slightly. They visually look very similar. You may need to drill new holes for the cotter pin if you didn't have the races pressed in all the way, and now you do.