Noe wheel shimmy & Nose Fork

Noticed a shimmy recently with our 7A at low speed during landing rollout.

Checked the tire pressure and it was low so added air and rechecked. Shimmy was much reduced but still present.

Lifted the nose off the ground and noticed lateral slop side to side when pushing on the tire.

Does the WD-630-1 fork have bearings ? Also noticed that I cannot buy a fork from Van's. Is there an aftermarket source ?

Thanks
Kevin

?Lateral slop side to side?. Can you describe this further, do you mean the wheel bearings are loose on the axle, or the fork is loose on the end of the gear leg?
Have you checked if this plane conforms to the Vans Service Bulletin on nose wheel forks?
Nose forks are available thru Vans, have you called their parts desk?

Check the breakout force. This was never a problem for my -7A for the first several years. I then had a shimmy incident on landing. I found the breakout force to be substantially different than the spec. Tightened it up to spec and the shimmy stopped. I check it at every annual condition inspection. I believe the force is 22lbs measured at the axle bolt.

Ralph Inkster said:

?Lateral slop side to side?. Can you describe this further, do you mean the wheel bearings are loose on the axle, or the fork is loose on the end of the gear leg?
Have you checked if this plane conforms to the Vans Service Bulletin on nose wheel forks?
Nose forks are available thru Vans, have you called their parts desk?

Click to expand...

Hi Ralph, not sure if is fork or wheel bearings as I have not taken it apart. No one home at Van?s till Wednesday. I was concerned asi could not find them at the online store. Day job will keep me bustY TIL FRIDAY. WILL UPDATETHEN. Thanks again and Merry Christmas
Kevin

Breakout force

I second the simple job of weighing the tail down and putting a simple fish scale on the nosewheel. When I bought my -10 the breakout force was VERY low. It is easily tightened and will almost certainly eliminate your shimmy. Our nosewheels are simple and easy to work on....

The fork does not have bearings and is available for purchase from Vans (see the nose gear leg and fork SB for part numbers). Be sure you have the new setup, especially if you ever plan to land on grass.

As mentioned above, the break-out force is your likely issue.

The fork has two replaceable shouldered bushings inside of it (press fit). Lateral play of the nose wheel could be wheel bearings, fork bushings (least likely) or slop in the leg/engine mount interface (most likely). You need to push back and forth on the wheel and observe each interface point to identify the slop.

All of this assumes that you are referring to a tilting type of side to side play and not referring to the rotating movement of the wheel/fork about the gear leg, as designed.

Larry

Problem solved. Bolt holding nose strut to engine mount had lost torque. Replaced with new bolt and nut. We had checked this at each condition inspection but just recently saw shimmy.
Phelps