This look ok to you?

[RLCarter]

20 minutes ago, PT20J said:

I'm still puzzled since the Service Manual doesn't show a max rearward dimension. Here's a thought: The new Mooney website has a forum with a section for Technical and Maintenance Tips which they have promised to monitor. Why not post this there and see what happens?

Skip

Would it matter, seeing how handling would only get better the farther back? Also as the discs (biscuits, doughnuts) wear it would move farther aft as well..... correct?

[PT20J]

2 hours ago, RLCarter said:

Would it matter, seeing how handling would only get better the farther back? Also as the discs (biscuits, doughnuts) wear it would move farther aft as well..... correct?

I think you are right and it should be fine. I’m assuming since there is no aft spec in the SB or my M20J service manual that it doesn’t matter. But still it would be interesting to see what the factory says.

[carusoam]

Some thoughts to sum up some of the issues...  a triple some/summary... 

1) The plumb bob tells everything... too far forward, steering can get wild... aka the 8 second ride...

2) As the donuts compress with time... the bob moves back...

3) The further back the bob moves, the more stable the steering is...

4) the aft limit seems to be running out of space during the retract...

5) Interesting note That skip posted... the reversible block with the off-center hole... pic by Rob.

6) Some nose gear geometries require a spacer... which doesn’t seem to be known by everyone... Gus did a fine job of documenting the plumb bob movement with pics...

7) Nose gear truss wear is the dangerous situation that puts the plumb bob forwards...

8) Rob also reported below... excess caster, or the bob moving too far back also comes with shimmy

Being merely a PP, and not a mechanic... and haven’t replaced a nose gear truss before... use this list solely to make sure you have most of the concerns covered...

Let’s also include @M20Doc in this fine holiday conversation... 

+1 for copying a link with this summary to the Mooney.com site...

Best regards,

-a-

[takair]

If the caster is too far aft, you may be prone to shimmy as the steering mechanism gets sloppy...so, if the gear goes up without interference and there is no shimmy, likely good handling qualities. If you get some shimmy, then look at the steering and the possibility of too much caster. 

[Nukemzzz]

The prop height I just measured at 10” which is the top of the limit. This is because my mains are squatting because I haven’t changed those donuts yet. I believe the consensus here it should be ok but be on alert if it doesn’t handle well during my first landings.  I have a good understanding of motorcycle and 4 wheel care steering and suspension dynamics but a tricycle gear with the nose wheel seeming to be trailing is new to me. I need to draw this out and think on it more. 
 

I think this wheel is still like a motorcycle. The rake is fixed. It isn’t changing when the shock disks compress. But the trail is getting longer. It’s below it and the distance between the two changes as the wheel compressed. On a motorcycle increasing the rake angle, stretching it, makes the bike more stable but harder to corner. What’s hard to picture here is the fact that the axle isn’t on the steering shaft centerline. I don’t yet understand why having a shorter trail (pre shim) makes it less stable and I don’t know why you would get a shimmy (instability in the mechanism) with an increased trail.  I suspect that increased trail makes it more stable at high speeds and less stable at low speeds. I’ll think on this some more. Lol

[RLCarter]

1 hour ago, Nukemzzz said:

I think this wheel is still like a motorcycle. The rake is fixed. It isn’t changing when the shock disks compress. But the trail is getting longer. It’s below it and the distance between the two changes as the wheel compressed. On a motorcycle increasing the rake angle, stretching it, makes the bike more stable but harder to corner. What’s hard to picture here is the fact that the axle isn’t on the steering shaft centerline. I don’t yet understand why having a shorter trail (pre shim) makes it less stable and I don’t know why you would get a shimmy (instability in the mechanism) with an increased trail.  I suspect that increased trail makes it more stable at high speeds and less stable at low speeds. I’ll think on this some more. Lol

Stretching (longer wheelbase) does increase stability if the “Trail” stays in check. Here’s a website I used HERE to get bikes to handle correctly. The nose gear on our Mooneys are more like a “Springer” front end than conventional suspension, there’s a guy on the west coast (Sugar Bear) that is the springer guru. 
 

You mention the mains have old disk, changing them out will change the Rake which changes........ lol

[Trenta]

I just delt with this when replacing the pucks. We did not install the additional laser collar when we did the new pucks on the front gear as it didn’t show in any diagrams that we could see however 1 trip around the pattern showed that there were huge ground controllability issues from the front wheel yanking the plane one side to the other and same on landing. Make sure that you refer to the correct directions weather it’s stock or the Lasar mod. 
 

-Trent 

[Nukemzzz]

Updated. During one landing it handled well. However I’m not entirely sure that the wheel isn’t hitting the top of the wheel well when retracted. That last inch of motion took some pushing. Need to get it back on jacks and double check that. 

[RLCarter]

You can look up in the wheel well with out jacking, shiny aluminum is the telltale sign

[Nukemzzz]

3 minutes ago, RLCarter said:

You can look up in the wheel well with out jacking, shiny aluminum is the telltale sign

I do see a black mark that has lines on it like the tire. That’s why I’m kinda wondering if it is touching. Maybe it’s an old mark. 

[jaylw314]

On 12/25/2020 at 8:27 AM, Nukemzzz said:

The prop height I just measured at 10” which is the top of the limit. This is because my mains are squatting because I haven’t changed those donuts yet. I believe the consensus here it should be ok but be on alert if it doesn’t handle well during my first landings.  I have a good understanding of motorcycle and 4 wheel care steering and suspension dynamics but a tricycle gear with the nose wheel seeming to be trailing is new to me. I need to draw this out and think on it more. 
 

I think this wheel is still like a motorcycle. The rake is fixed. It isn’t changing when the shock disks compress. But the trail is getting longer. It’s below it and the distance between the two changes as the wheel compressed. On a motorcycle increasing the rake angle, stretching it, makes the bike more stable but harder to corner. What’s hard to picture here is the fact that the axle isn’t on the steering shaft centerline. I don’t yet understand why having a shorter trail (pre shim) makes it less stable and I don’t know why you would get a shimmy (instability in the mechanism) with an increased trail.  I suspect that increased trail makes it more stable at high speeds and less stable at low speeds. I’ll think on this some more. Lol

My understanding is that shimmy is a problem with damping, not stability.  More trail gives you more stability (increased centering force) without necessarily increasing damping.  I don't understand enough about suspension geometry to know what factors increase damping.

[RLCarter]

3 hours ago, Nukemzzz said:

I do see a black mark that has lines on it like the tire. That’s why I’m kinda wondering if it is touching. Maybe it’s an old mark. 

Verify you have the correct tire pressure, get it up on jacks, disconnect the gear door rods and retract the gear, you should be able to spin the nose wheel. If you don’t have access to jacks or don’t feel like jacking the aircraft, clean the suspect area and put masking tape over the area and go fly, the tape will now show the telltale if it’s rubbing. There are adjustable bushing that dictate how far up in the well the nose gear goes, service manual walks you through the process if needed