Pedal and Yoke Wobble on Braking

[Perilous]

Hello out there!

I'm new to the post as of today, and already I'd like to attend a posted fly-out this Sunday here in California to meet other die-hart Mooney owners.

I bought a nice 1977 J20 in August and I've enjoyed it immensely. The one problem I'm having now is a severe wobble in the peddles and yoke when I apply the brakes hard at the end of a landing run out.

I've been told it could be a warped disc, a flat spotted tire or even a loose fitting in the nose wheel. I do have a slight flat spot on the right main, but it's been that way since my first flight when I accidentally grabbed too much brake on a landing, and it hasn't gotten worse. When I spin the mains when it's jacked-up, I don't notice any dragging in the discs. So far, I'm living with the problem as it wobbles only when I apply the brakes hard while pulling back the yoke. 

Has anybody out there experienced this problem before?

I'd appreciate any feedback. Thank You, and glad to be here to network with other Mooney owner. I go by the name of "Perilous"....

 

[Andy95W]

My guess is nose wheel shimmy which is then transmitted through the rudder/aileron interconnect to the yoke.  Not applying back pressure to the yoke would load up the nose gear and may prevent the shimmy- or may make it worse.

Just a guess, the disc brake is also possible, but in my experience not as likely.

[carusoam]

Andy has nicely explained why you feel it in the yoke.  Airlerons don't typically cause this challenge at normal speeds. Flying well past VNE may be a different challenge.

the brake discs should be pretty easy to separate as a candidate from the other possibilities without even flying. Warped disks will have a pretty regular oscillation that changes as you slow.  And stops as you let off the brake.

If the tires have set from a long period (months) of time of not moving they get out of round. They usually get round after use.

The nose wheel is not attached to any brakes, but it does load up more as the mains are braked.

Find a thread regarding nose gear.  There is a new one this week.  It has all the references that will get you up to speed including pictures.  Use the search box at the top of your screen.  It is a newly enhanced feature of MS

I am only a PP, not a mechanic,

-a-

[Piloto]

Check the nose wheel to pedals linkage. When braking hard you may be having full force on the top of the pedal but not on the bottom. If there is steering backlash on the linkage it may wobble.

José

[garytex]

Mine did that, first during breaking, later whenever it felt like it. Had to replace a complicated little pivot arm part high and forward in the nose gear well that controlled stearing. Hope that's not your case, it wasn't cheap.

Gary

[N400YS]

I agree with a loose bushing on the steering horn!!! Happen to me....don't wait before it get worst!!!! It was scary for me!

I replaced mine by a lasar retrofitted one!

 

problem immediately solved

[TomHuff]

Jacking the aircraft quickly revealed that there was excessive freeplay in the nose gear. Swapped in a re-bushed and reconditioned steering horn from LASAR (with core credit) to tighten things right back up.

Tom

[carusoam]

Welcome aboard Tom.

Generous first post sharing your experience.

Best regards,

-a-