Main landing gear wheel alignment

[woodman86]

Hello I am a new Mooney owner of a 1964M 20 C I noticed on our test flight and landing it was pretty Squirrley and visually notice that the main landing gear  wheels angle out at the top pretty extreme and actually they’re both different one is a quarter inch more than the other I put a digital level on the tires is there an adjustment for this?

[Hank]

Squirrely landings are often caused by worn nose gear bushings. Google Don Maxwell's article "The 8-Second Ride" for details. 

[MB65E]

Sweet hangar!!

-Matt

[Andy95W]

Welcome aboard. My M20C is pretty close to your SN, my right main gear looks similar to yours. 

There is not an adjustment for that angle.  If your A&P doesn’t understand Mooney landing gear and tries to adjust it, he will screw up the gear rigging tension and the landing gear will collapse.

Like Hank said, squirrelly behavior on landing is a result of the nose gear.  Either the angle of the lower leg is off (this can be adjusted by a different size spacer above the nose gear shock discs) or the nose wheel to rudder rigging is off.

[Prior owner]

Definitely look at your rudder to nose wheel rigging. Also, what tires pressures are you running…? 30 psi for all three tires?

[carusoam]

Welcome aboard Woody!

Keep in mind…

1) a single test flight is pretty hard to judge a plane…. Unless you have a lot of Mooney flying experience beforehand…

2) Often… People buying a Mooney… have a Pre-purchase inspection completed before committing to the purchase… 

3) Following a well organized purchase… Transition Training is highly recommended…

4) These actions are done with highly Mooney skilled people…

 

This way you don’t get surprised with…

5) Is it me?

6) Is it the machine?

7) Was it the squirrelly winds?

 

Sounds like you have a lot to figure out… and plenty of time to learn about your new machine…

8) Has the plane seen a Mooney specific mechanic in its recent lifetime?

9) Fortunately, you have come to the right place…. You have a lot to learn, and there is no place like MS who has a lot of knowledge to share…

10) Share some of your background, ask dozens of questions…

You won’t be the first person to wonder why their wheels look a bit funny….

 

Go MS! 

Best regards,

-a-

[woodman86]

I did reed the 8  second article that was good, I haven’t checked the pressure yet haven’t got all my tools together but it seems like the caster or camber of both tires should be the same if your car was like that you’d never be able to keep it on the road

[carusoam]

1 minute ago, woodman86 said:

I did reed the 8  second article that was good, I haven’t checked the pressure yet haven’t got all my tools together but it seems like the caster or camber of both tires should be the same if your car was like that you’d never be able to keep it on the road

If your car does anything a Mooney does…

You are going to be pleasantly surprised!

Caster and camber are critical for holding corners doing 1g turns…

We probably don’t do 1g turns in the Mooney… unless your were really cornering hard during your landing?

-a-

[woodman86]

As a matter of fact my car is fast like a Mooney  and starts with a M, lol

[carusoam]

Woody,

has your plane been to Lasar at all?

Lake Aero Styling…

It may have been to the home of a really good Mooney Service Center…

Its possible that Lasar has moved locations…

 

Check your logs…

Be on the look out for what has been changed…

Every decade or so… the rubber donuts get changed…

If yours have been there too long, or something strange is occurring…. It may be time to put in some new parts…  there is a steel tube hiding under the donuts… if it is original… it may want to get out…

PP thoughts only, not a mechanic…

Best regards,

-a-

[Prior owner]

8 hours ago, woodman86 said:

I did reed the 8  second article that was good, I haven’t checked the pressure yet haven’t got all my tools together but it seems like the caster or camber of both tires should be the same if your car was like that you’d never be able to keep it on the road

Sounds like you need to jack the whole plane, confirm that the tire sizes are correct, tire pressures, check wheel bearing tightness and condition, nose wheel/rudder/pedal alignment, nose gear pivot bolt bushing condition & torque, steering horn condition, condition of steering rod ends, nose gear truss for play/ proper shimming, main gear bushing wear, condition of Lord discs (did someone replace the discs on only one main gear? (I have seen this done, and don’t recommend it).

The addition of the nose gear strut spacer kit isn’t a magic bullet- it will only work if caster is the reason for your woes…almost all of the time I have been able to correct tracking issues without installing the spacer. Investigate- Good luck!

[N201MKTurbo]

The main wheels used to be vertical. There was a service bulletin back in the 60s that made them angled. They are all angled now.

[A64Pilot]

Land only on the mains, if the problem is with them it will be squirrely.

But if the misbehavior begins when the nose touches down, it’s likely there.

That angle is called camber and I would be very surprised if it’s causing an issue, but there are a few things with the nose wheel that can.

https://en.wikipedia.org/wiki/Camber_angle

 

Edited February 15, 2022 by A64Pilot

[carusoam]

@Joshua Blackh4t seeing if Josh is in this neighborhood…

-a-

[Joshua Blackh4t]

2 hours ago, carusoam said:

@Joshua Blackh4t seeing if Josh is in this neighborhood…

-a-

Haha, yep, following this as well.

As others are saying, depends on what kind of squirrel. 

I'm trying to track down pure shimmy. Its either there or not and a sharp input can stop it. I'm so ready for it now that passengers wouldn't even know it happened. It gets worse if I have forgotten to check tyre pressure and it gets down to half. 

The tyre is old and will be replaced asap. Hoping that fixes it. 

I'll be trying my digital level on the nose rig this weekend and will post results.

Not sure woodman86 has the same issue as me, but from my ultralight time, mains seem to get away with all sorts of things, nose wheels are just about always the problem. 

 

 

[Bartman]

On 2/16/2022 at 4:33 AM, Joshua Blackh4t said:

Haha, yep, following this as well.

As others are saying, depends on what kind of squirrel. 

I'm trying to track down pure shimmy. Its either there or not and a sharp input can stop it. I'm so ready for it now that passengers wouldn't even know it happened. It gets worse if I have forgotten to check tyre pressure and it gets down to half. 

The tyre is old and will be replaced asap. Hoping that fixes it. 

I'll be trying my digital level on the nose rig this weekend and will post results.

Not sure woodman86 has the same issue as me, but from my ultralight time, mains seem to get away with all sorts of things, nose wheels are just about always the problem. 

 

 

Thats exactly what mine did before I sent the nose truss to LASAR for rebuild and got a new steering horn.  

[cliffy]

On 2/14/2022 at 10:05 PM, woodman86 said:

As a matter of fact my car is fast like a Mooney  and starts with a M, lol

Mine just keeps Rolling along like my Mooney

[Jim Peace]

On 2/14/2022 at 11:56 PM, carusoam said:

8) Has the plane seen a Mooney specific mechanic in its recent lifetime?

I found this really has no bearing on whether or not the plane is "right."

Some of the worst mx my airplane has received has been at a MSC.  The list of issues is long but I will just stick to the gear for now.

I had a MSC do an annual for me.  They worked on the gear preloads (which felt fine prior to the annual) and did whatever they had to do. My first flight after annual I could not get the gear down (Johnson bar) with one hand.  I had to struggle with two hands and at one point I did not know if I could do it.  I took a break and then resumed the struggle with two hands and finally got it locked down.  

I took it back to them and they still could not get it right.  I asked them if they swung the gear after working on it and all I got was a shoulder shrug.  These MSC have so many people working in them that nobody knows who is doing what...

I had a friend who is a non Mooney mechanic.  Actually it was his first time working on a Mooney and I suggested he call LASAR on how to fix it.  I am a good customer with them and they were okay with spending 15 minutes with him on the phone.  Less than 30 minutes later we did a gear swing and it felt right again.  Its been great ever since.  

Not all MSCs or Mooney mechanics are created equal.  Be careful out there.

 

[Utah20Gflyer]

During my planes first annual we found there was a 1/4 to 3/8 side to side play in my main landing gear.  The cause was some worn parts and lack of adequate tension.  I was fortunate to get the problem fixed before the gear collapsed on me.  I would suggest jacking up the plane, check for potential damage/wear and correct tension as that is quick and inexpensive insurance against a very expensive gear collapse.   

[carusoam]

10 hours ago, Jim Peace said:

I found this really has no bearing on whether or not the plane is "right."

Some of the worst mx my airplane has received has been at a MSC.  The list of issues is long but I will just stick to the gear for now.

I had a MSC do an annual for me.  They worked on the gear preloads (which felt fine prior to the annual) and did whatever they had to do. My first flight after annual I could not get the gear down (Johnson bar) with one hand.  I had to struggle with two hands and at one point I did not know if I could do it.  I took a break and then resumed the struggle with two hands and finally got it locked down.  

I took it back to them and they still could not get it right.  I asked them if they swung the gear after working on it and all I got was a shoulder shrug.  These MSC have so many people working in them that nobody knows who is doing what...

I had a friend who is a non Mooney mechanic.  Actually it was his first time working on a Mooney and I suggested he call LASAR on how to fix it.  I am a good customer with them and they were okay with spending 15 minutes with him on the phone.  Less than 30 minutes later we did a gear swing and it felt right again.  Its been great ever since.  

Not all MSCs or Mooney mechanics are created equal.  Be careful out there.

 

Jim,

How long have you known me? 

I hear ya…. But….

 

Read closer…

Mooney specific mechanic… the guy with the wrench… I didn’t actually mention the MSC…

MSC… The building that some mechanics work in… not all mechanics in the MSC are Mooney related or even aircraft related….  

 

I probably wasn’t too specific when I wrote that paragraph…

Best regards,

-a-