Nose Gear Woes!

[CharlesHuddleston]

Ok, so after a recent landing, had a horrible shimmy in the nose wheel, that settled once we slowed way down. Taxied on in, at first afraid of a flat tire. Noticed I had lost rudder input for steering so had to use differential braking to park. On exam, the steering horn was dangling free, and it appears that the bolt between it and the nose-gear frame was gone, and it had snapped off the lug coming from the tubular cross-beam in the top/front of the nose wheel well. My A&P is going to look at it, but as they have a Mooney as well, he recommended reaching out to the community to see if anyone could add some guidance. Going to put it on the Mooney FB page as well. Wondering if the lug can be re-welded on the cross-member. Tried to include some pics, and circled the lug location. Thanks for any input!

[carusoam]

Nicely handled impromptu steering challenge...

Since hardware alignment is usually important for the normal steering method...

Add getting a used / rebuilt device to your list of Possible solutions...

While trying to sort out what could have caused this particular failure...

Broken steering parts or landing gear rods are usually caused by something over stressing them...

Find out what did the overstressing...

PP thoughts only, not a mechanic...

 

Best regards,

-a-

[RLCarter]

Looks to be a lot of corrosion, looking where it’s broken off should shiny but it’s dark in color which indicates it’s been cracked (failing) for some time. Looking at the photos I would have the entire nose gear assembly and mounting points inspected, big bucks if it collapses...

[Yetti]

Looks like the weld did not fail, but right below the weld the metal fatigued.  It looks to be a steering point, not a retractable gear thing.  Don't have any letters behind my name, but I would grind off the remaining nub and find a welder that can weld a new post back on.     Baring that, you could grind it off the nub and fit a half piece of tubing with matching ID with a post welded with bolts to either side to fasten to the original tubing.

Edited January 10, 2020 by Yetti

[Yetti]

Or just remove all that linkage and pretend you have Cirrus with caster nose steering.

[tmo]

3 hours ago, RLCarter said:

Looks to be a lot of corrosion

You mean to the right of the red circle in the first photo?  Genuinely asking so I know what to look for, because otherwise it looks to my untrained eye like it's mostly dirt and grease.

[N201MKTurbo]

That bolt was either a welded pivot pin or a bolt through a boss. Yours looks like it may be the bolt. You may just need to drive the rusty bolt out and replace it.

[CharlesHuddleston]

1 hour ago, tmo said:

You mean to the right of the red circle in the first photo?  Genuinely asking so I know what to look for, because otherwise it looks to my untrained eye like it's mostly dirt and grease.

In the first picture, with the red circle, the stub is what I believe is left. Tried to use pictures from the illustrated parts catalog to compare. 

[PT20J]

My M20J IPC calls out 2 different studs depending on serial number (I have no way of knowing what the difference is but a MSC might be able to tell from the Parts Portal) and the K is probably similar. If it were me I would measure the pieces and have one fabricated since the factory is closed and it doesn’t seem like a part that a MSC would stock. It’s welded to a structural tube, and the geometry is going to be critical, so I’d want to make sure that I got someone that knows what they’re doing to replace it. I’d consult with Don Maxwell or Tom Rouch - they’ve seen just about everything.

Skip

[Guest]

I thought that LASAR has a kit to replace the broken pin with a clamp that mounts on the tube with a new pin.

Clarence

[Yetti]

Looks like it might be a bolt.  item 16

 

[chriscalandro]

3 hours ago, tmo said:

You mean to the right of the red circle in the first photo?  Genuinely asking so I know what to look for, because otherwise it looks to my untrained eye like it's mostly dirt and grease.

It's just dirt, oil, and grime.  I don't see any corrosion.

Edited January 11, 2020 by chriscalandro

[RLCarter]

 

6 hours ago, tmo said:

You mean to the right of the red circle in the first photo?  Genuinely asking so I know what to look for, because otherwise it looks to my untrained eye like it's mostly dirt and grease.

Ok, doesnt look as bad on a computer screen as it did outside on my phone

[Guest]

It looks like the pin which is welded to the forward cross tube is broken off and is stuck in the steering tee, as shown in photo 1&3.  Charles did someone that the bolt out of the tee or did it break off and fall out?

 

[MB65E]

Frustrating that it’s a welded stud on the J. 
the older airplanes had the boss with the bolt. Some even had bearings. 
-Matt

[larrynimmo]

Here are pictures from my m20j

[CharlesHuddleston]

4 hours ago, M20Doc said:

It looks like the pin which is welded to the forward cross tube is broken off and is stuck in the steering tee, as shown in photo 1&3.  Charles did someone that the bolt out of the tee or did it break off and fall out?

 

I am assuming that it either fell out or broke and then fell out. I believe once it was out and lost, it allowed the stress to break the steering pin. Ugh... the joys of plane ownership!

[CharlesHuddleston]

Thanks @larrynimmo, that is the million-dollar shot I was looking for! Shows it offset on the leading edge of the cross-member. Now to find someone that can re-create it!

[carusoam]

See what is in the store... Nose steering parts...

@Alan Fox

@acpartswhse

@SheryLoewen
 

-a-

[PT20J]

I wonder what caused the stud to shear? Doesn’t seem like it should be heavily loaded; it’s just a pivot point in line with the centerline of the nose gear truss. Corrosion? Fatigue due to shimmy or some other vibration? Lack of lubrication? 

Has anyone else seen this failure?

Skip

[N201MKTurbo]

If there was something wrong with the pivot that the steering horn rotates around during retraction, it could tear the pin off while the gear was swinging.

[larrynimmo]

Is the broken spindle still inside the arm?

close examination should give you a clue as to what caused it to shear.

like pt20j stated, there should be very little stress on the fixed spindle....I almost think somehow it became cocked and created a twisting load to create a snapping force....a chain is only as strong as it weakest link 

I’m sure you already know that it will be extremely difficult to weld a new spindle in place...however, it should be easy to grind the old one off

[PT20J]

28 minutes ago, N201MKTurbo said:

If there was something wrong with the pivot that the steering horn rotates around during retraction, it could tear the pin off while the gear was swinging.

Great thought! I re-read the original post and looked at the pictures again. The bolt (34 in the diagram in Clarence's post) is missing. It looks like if the nut came off, the bolt would be vertical and head down when retracted and could fall out. So if the bolt fell out when retracted, things might jam up on the subsequent extension. The missing bolt and nut would have fallen out when the gear doors opened. Think I'll check the torque on my bolt.

Skip

[N201MKTurbo]

If you remove the SS panel at the bottom center of the firewall, you actually have good access to the pivot post.

[CharlesHuddleston]

As an afterthought, I’m just glad the gear came down and locked! Again, it was fairly easy to steer with it free-wheeling, but it could have been real bad had the steering horn got caught in the way of the gear extension. Also, reading the parts catalog sub-heading, the bolt that is missing was supposed to have a cotter pin. It all starts with one thing missing. BTW, does anyone have any info on how long that bolt is? Parts catalog just a lists it as an AN4-21, but doesn’t give length. Would like to go ahead and order that part for sure.