Nose Wheel Shimmy

[jayrobinson1942]

My 1967 M20C has developed a significant nose wheel shimmy on landing roll out.  All linkage seems tight with little or no play in the rod end bearing.

[Piloto]

Have you check the wheel balance? Verify the tire air valve is line-up with a red mark on the inner perimeter of the tire.

José  

[Sven]

Check out the folowing threads. Don't ignore it. I blew a tire on landing because of this. I've been told I was lucky as a few planes have had the nose gear send them over runway lights or through fences.

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=2&threadid=1097

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=2&threadid=1180

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=2&threadid=1120

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=2&threadid=1120

I know it's a lot of reading but I hope it helps.

-Sven

 

[takair]

Sven points out lots of good info.  I have a 64 E model.  I had what I would consider a "darting" on both take off and landing, especially at rotation.  This can also manifest itself as shimmy if conditions are right.  You can check the rudder for play.  If you have lots of free play, left/right you may have worn nose gear steering linkage. (can't recall the limits). The thing that compounds this is the collar that many people speak of.  I seem to recall that my collar was symetrical.  You can get a shim to fix this.  Mooney has an SB to correct this condition.  See http://www.mooney.com/images/pdfs/sb-pdf/sbm20-202.pdf.  From my experience look at both the steering linkage and the SB 20-202 to correct this condition.  Age/condition of the shock pucks can also play into this.  I flew mine way too long without correcting it.  It was like a new airplane after I fixed it.  Good luck.

[ReggieM]

In addition to what takair mentioned above, here's an article written by Don Maxwell about the SB:

http://www.donmaxwell.com/publications/MAPA_TEXT/M20-202%20-%20Eight-Second%20Ride/EIGHT_SECOND_RIDE.HTM

- Reg