Difficulty installing landing gear truss

[Hradec]

Hi, 

I'm a bit frustrated after renovating my landing gear and rebushing the truss and the link. I installed the right main landing gear with the trust and the link attached to the main landing gear.

The truss is about a half an inch away from being bolted to the spa. I know that this area can accept a thin Shim as well as shimming the landing gear fore and aft movement. But this will definitely not close the half inch Gap. What am I doing wrong?

The truss and the link we're rebushed  using recommended clearances of .002" by Dan at Lasar.

I was going to work on the left main landing gear tomorrow to see if I have the same problem there. Any recommendations? Is the clearance on the truss and Link too tight? Is slop required in order to attach the Truss to The Spar?

Thanks 

Glenn

1964 m20e

Trying to finish up the aft stub spar and upper spar cap replacement 

 

 

[Kelpro999]

Have you verified any left vs right parts have not been interchanged?

[47U]

13 hours ago, Hradec said:

The truss is about a half an inch away from being bolted to the spa.

I’m having trouble visualizing your problem… got a picture?  (Sorry if I’m a little dense.)

[McMooney]

yeah, i don't truss your description, send a pic

[Kelpro999]

21 hours ago, Hradec said:

Trying to finish up the aft stub spar and upper spar cap replacement 

Interesting, Is this a corrosion repair or failed structural issue?

[hammdo]

One of many posts of what’s been done:

 

[Hradec]

Well I pretty much have it resolved, however now I have interference elsewhere.

The truss pivot bolt head is hitting. Parts manual calls for an6H21a

Service  bulletin m20-212 replaces there bolts with NAS1306 bolts,these have a considerably thinner head but the length called out for in the sb is too short. I want to replace bolt A.. remove an6h-17a install nas1306-21h. Will be too short. My goal is to replace an6h21a bolt with an Nas equivalent but with a thinner head. Specs say nas1306-26h is the one to use for my 1964 m20e sn 311. Any one run into this bolt interfering. This is not the an26-17 with the thin castle nut that hits. I have this resolved.

 

Thx

Glenn

[47U]

13 hours ago, Hradec said:

Any one run into this bolt interfering.

I’m going to try to be helpful, but I’m pretty sure I won’t be.  

First off, SB M20-212 doesn’t apply to the E model.  Applicability starts with the M20F sn 660003 and runs into the early J models.  That notwithstanding, I wouldn’t think there’s any harm in swapping the AN hardware for NAS hardware.  There’s another (probably irrelevant) point, your MLG pn is 520000- and the SB MLG pn applies to 520001-.  Not sure of the significance… probably none?  Lastly, have you put new bushings in the linkages.  Worn bushing can contribute to sideways movement (elementary, please forgive).

Good luck, please let us know your progress.

[Kelpro999]

15 hours ago, Hradec said:

Well I pretty much have it resolved

Curious what change made up that much difference in truss position?

[Hradec]

On 6/8/2024 at 2:17 PM, Kelpro999 said:

Curious what change made up that much difference in truss position?

Most likely the truss and link bushing replacement. 

[mooniac15u]

On 6/7/2024 at 11:23 PM, Hradec said:

Well I pretty much have it resolved, however now I have interference elsewhere.

The truss pivot bolt head is hitting. Parts manual calls for an6H21a

Service  bulletin m20-212 replaces there bolts with NAS1306 bolts,these have a considerably thinner head but the length called out for in the sb is too short. I want to replace bolt A.. remove an6h-17a install nas1306-21h. Will be too short. My goal is to replace an6h21a bolt with an Nas equivalent but with a thinner head. Specs say nas1306-26h is the one to use for my 1964 m20e sn 311. Any one run into this bolt interfering. This is not the an26-17 with the thin castle nut that hits. I have this resolved.

 

Thx

Glenn

I can’t tell from your description exactly what’s interfering so I’ll throw this out there. There’s a small bracket that should have been replaced when your landing gear was converted to the new style of shock discs but I’m not sure this always happens and I think if there’s enough play in older gear it might not cause a problem. It’s described in Mooney service bulletin M20-139 https://www.mooney.com/wp-content/uploads/2020/12/SBM20-139A.pdf. On page 4 item 8 describes the bracket that needs to be replaced. On page 6 under “Main Gear Parts to Install” item 6 is a note that the gear won’t retract unless this bracket is replaced.

 

I’m not saying this is necessarily your problem but it seems worth confirming that you have the new bracket.

[Hradec]

7 hours ago, mooniac15u said:

I can’t tell from your description exactly what’s interfering so I’ll throw this out there. There’s a small bracket that should have been replaced when your landing gear was converted to the new style of shock discs but I’m not sure this always happens and I think if there’s enough play in older gear it might not cause a problem. It’s described in Mooney service bulletin M20-139 https://www.mooney.com/wp-content/uploads/2020/12/SBM20-139A.pdf. On page 4 item 8 describes the bracket that needs to be replaced. On page 6 under “Main Gear Parts to Install” item 6 is a note that the gear won’t retract unless this bracket is replaced.

 

I’m not saying this is necessarily your problem but it seems worth confirming that you have the new bracket.

Thanks for the input. Somewhere I have seen it read that you could modify the existing  part by machining the corners off of this bracket 510046. My bracket has been changed or modified 

To the proper status. So many new parts and and adjustments. Not much room for all that monkey motion. Gear is in and clearances good now. New shock disks installed. She will be sitting on her gear in a week or two.  First time in 4 yrs.

Thanks

Glenn

 

[Kelpro999]

22 hours ago, Hradec said:

Somewhere I have seen it read that you could modify the existing  part by machining the corners off of this bracket 510046.

 Cutting 0.3” off the end of p/n 510013 can be done in place of p/n 510046-000, however, this modification is only applicable through m20B models and not beyond. I’ve contacted Mooney about this and no reason other than it’s not listed in later service bulletins. I believe there may be more early “C”s running around with modified xxxx13 brackets than with xxxx46-000. If your larger dia. Disc top plate clearance is good then it works.