Door Latch Adjustment / Re-Keying For Single Key

[RLCarter]

After putting it off for several years I finally decided to adjust the cabin door, it now has a very positive over-center and holds the top latch secure. Since I’ve owned my Mooney the door has never really had a positive feel when rotating the interior handle forward to latch the door closed and the exterior handle always stuck out farther than I thought it should have. I’ve never had the door come open in flight but I did get a ton of wind noise around the top of the door. Another thing that I didn’t like was having separate keys for Ignition switch, Cabin Door and Baggage Door. I didn’t take any photos but I do have the drawing out of the Parts Catalog along with a few I did for replacing the Door locks. The following drawing is from the 1965~1967 M20C, 1965~1966 M20D, 1965~1967 M20E and 1967 M20F Parts Catalog. The first thing was to remove the plastic cover from the cabin door, and in typical Mooney fashion I ended up with a pile of screws. After the cover was removed and the door open I was able to find part of the problem, there was pink fiberglass insulation packed in and around the interior door handle up inside the door (Area “A”). Once the insulation was removed rotating the interior handle forward felt a lot more positive but still no over-center that I could tell. I knew my top latch needed adjusting due to the wind noise so I started there. The upper latch assembly (#6) comes out as a unit, start by loosening the jam nut on the clevis (#24), then remove the small screws that holds the assembly in place, there are 2 machine screws that come in from the top. Care should be taken when removing the cotter, washer and clevis pin from #24, don’t drop them in the door. Once the latch assembly was out I got a better idea as how it all worked, item #18 is a stop, keeping it from going to far over-center. I turned # 24 2 full turns in (shorter) and re-installed the assembly (#6). I could now feel in the handle it going over-center but it was more pressure than I liked. Removing #6 and turning #24 in 2 more turns did the trick. The interior handle now has a positive lock and the outside handle fits nicely with the door. With the door closed and latched I wasn’t able to pry the top of the door away with my finger tips as before and it felt very secure.

 

                                                                       

 

The next thing was to look at the locks for the Cabin & Baggage doors. Ideally I want just 1 Key that works the Ignition and both door locks. I removed the lock assemblies from the doors but was unable to remove the cylinders to key them the same as the ignition. I stopped by a local Locksmith shop to see if they had any lock assemblies that could be keyed to my ignition key but they had just sold all 20 something they had in stock (figures). I stopped by Lowe’s to see what they had but no joy, Home Depot was my next stop and it was a score, Gate House # 0252974 looked like they would foot the bill but I wanted to make sure my original Bendix ign. key would fit the new locks. A clerk came by and asked if I needed help and told him I want to see if this key fit in that lock, he opened that package and the key went right in, plus the key cut was very close to mine. Once home I removed the cam which allowed the cylinder to be removed from the body. The way most locks work is the body of the lock has a keyway (these have 4) and the wafers/pins are spring loaded into that keyway, keeping the cylinder from turning (unlocking), when the key is inserted into the cylinder the cut of the key allows the wafers/pins to be pulled into the cylinder out of the keyway which allows the cylinder to turn. These were never meant to be re-keyed and the wafers were not removable. By inserting my ignition key in the cylinder I could see which wafers stuck up past the cylinder. The drawing below shows what I’m talking about. The wafers are brass and easily filed down to the radius of the cylinder allowing it to rotate in the body. Filing is done with the key inserted (fully), once they are filed down insert the cylinder with the key installed and check that it rotates freely in both directions completely. Once all the filing is done clean out all the metal filings and reassemble. I had to modify the cams to match the originals but its fairly straightforward looking at them side by side. Pay close attention to your old locks on orientation in the locked and un-locked positions, the new locks can be set by how the “Rotation Washer” is installed. Once I had both new locks keyed and correct (after a test fit & try) the cam is held on with a screw, which was removed and installed back with thread locker (loctite). As an added measure once the locks were in place and tightened I verified that they worked as needed, I then added several dabs of RTV on the nut/body/door skin and the screw/cam for safety. I now have 1 key that works the ignition switch and both door locks……..Hope I explained this well enough and if not shoot me a message and I’ll try to explain it better.

                              

 

Edited October 17, 2019 by RLCarter

[carusoam]

That was really clear...

And very interesting...

The end result is even better...

1) One Key for all three locks.

2) Door closure mechanism now works as designed.

That had to take a lot of time...

Thanks for sharing the details, Robert!

Best regards,

-a-

[RLCarter]

Just now, carusoam said:

That had to take a lot of time...

Not too long, maybe 6 hrs over 2 days, but well worth it. My prop is off for IRAN so I haven't flown it to see if the noise level has gone down, but it should......

[jamesm]

Nice write up on the door & locks. On my '67C in the door  lock linkage has welded abutments. I took one end of a spring attached to one of the welded abutments then attached the other end of the  spring to door frame near front passagener's elbow is. That way there is constant  tension on the door handle. The spring tension is very slight, I think it is something like 2 lbs pull. It has always bugged me  when taking first time passengers up having to explain to them why I was reaching over to the door handle  to make sure the door wasn't going to open in flight after large power changes. I think the door has open on me in flight maybe twice because my passenger (co owner at the time) was messing with handle on climb out. Both times where when he was in the front passenger seat.  I  have always very hesitant to mess with the door rigging afraid that I  would make it worse.

[rbridges]

great write up.  Thanks for taking time to post it.

[RLCarter]

6 minutes ago, jamesm said:

 I  have always very hesitant to mess with the door rigging afraid that I  would make it worse.

I was the same, I couldn't find much in the service manual or elsewhere, the parts manual gave a better idea of what needed to be done

[0TreeLemur]

I will be really interested to hear if it stops the noise from your upper door.   We've got the same issue and a seal replacement didn't fix it.   One difference is that our door seems to be well adjusted in terms of over-center and appropriate required pull to actuate the handle.    Thanks for sharing!

[RLCarter]

8 hours ago, 0TreeLemur said:

I will be really interested to hear if it stops the noise from your upper door.   We've got the same issue and a seal replacement didn't fix it.   One difference is that our door seems to be well adjusted in terms of over-center and appropriate required pull to actuate the handle.    Thanks for sharing!

will let ya know in a few weeks when my prop comes back. What door seal did you use?, mine has the one on the frame (cant remember manufacture) but its junk, will be going back with OEM seal (door mounted) in a few months

[0TreeLemur]

I went with the expensive door seal from knots2u.com   It is a good seal.   We got good seal action everywhere but about the 10-11 o'clock position on the door.  I think adjustment of the top latch might be the ticket, but not sure.  Everything else about the door seems great.   I'll wait for your pirep before taking any action.

 

[RLCarter]

On October 17, 2019 at 10:44 AM, 0TreeLemur said:

I will be really interested to hear if it stops the noise from your upper door.   We've got the same issue and a seal replacement didn't fix it.   One difference is that our door seems to be well adjusted in terms of over-center and appropriate required pull to actuate the handle.    Thanks for sharing!

Kinda late getting back with you, with the top latch adjusted correctly made a HUGE difference in cabin noise. Went up this morning spent  1.7hrs with my CFI and he made several comments on how much quieter it was which reminded me that I hadn't reported back. Today I also removed my headset which I hadn't done post adjustment and it wasn't too bad

[carusoam]

Great follow-up RLC!

Best regards,

-a-

[RLCarter]

2 hours ago, carusoam said:

Great follow-up RLC!

Best regards,

-a-

Better late than never.....

[FastTex]

On 10/17/2019 at 10:45 PM, 0TreeLemur said:

I went with the expensive door seal from knots2u.com   It is a good seal.   We got good seal action everywhere but about the 10-11 o'clock position on the door.  I think adjustment of the top latch might be the ticket, but not sure.  Everything else about the door seems great.   I'll wait for your pirep before taking any action.

 

I made the same mistake buying the "frame" seal and, as @RLCarter stated, it's junk. It sticks well but it's all coming apart piece by piece. Did you also use the remover and glue suggested by knots2u.com? I'm thinking to re-replace mine...

[ArtVandelay]

I went with the expensive door seal from knots2u.com   It is a good seal.   We got good seal action everywhere but about the 10-11 o'clock position on the door.  I think adjustment of the top latch might be the ticket, but not sure.  Everything else about the door seems great.   I'll wait for your pirep before taking any action.
 

Does the door still remain flush with the fuselage?
I had what looked like is the same seal, and my door would not close completely because the seal was too bulky.


Tom

[0TreeLemur]

My door is flush.  I've asked the shop doing the annual to try and adjust the top hook to close the gap that remains based on some hissing that is happening at the ~10 o'clock position looking outward.

[0TreeLemur]

6 hours ago, FastTex said:

I made the same mistake buying the "frame" seal and, as @RLCarter stated, it's junk. It sticks well but it's all coming apart piece by piece. Did you also use the remover and glue suggested by knots2u.com? I'm thinking to re-replace mine...

yes I used the tank sealant remover from knot2u that has a citrus smell.   Worked well.

[Fry]

Hi there,

I am contemplating to do the same to my M20J. Does anyone know if the locks are the same between F and J?

Thanks,

Fry

[Mooney-Shiner]

On 10/17/2019 at 12:02 AM, RLCarter said:

After putting it off for several years I finally decided to adjust the cabin door, it now has a very positive over-center and holds the top latch secure. Since I’ve owned my Mooney the door has never really had a positive feel when rotating the interior handle forward to latch the door closed and the exterior handle always stuck out farther than I thought it should have. I’ve never had the door come open in flight but I did get a ton of wind noise around the top of the door. Another thing that I didn’t like was having separate keys for Ignition switch, Cabin Door and Baggage Door. I didn’t take any photos but I do have the drawing out of the Parts Catalog along with a few I did for replacing the Door locks. The following drawing is from the 1965~1967 M20C, 1965~1966 M20D, 1965~1967 M20E and 1967 M20F Parts Catalog. The first thing was to remove the plastic cover from the cabin door, and in typical Mooney fashion I ended up with a pile of screws. After the cover was removed and the door open I was able to find part of the problem, there was pink fiberglass insulation packed in and around the interior door handle up inside the door (Area “A”). Once the insulation was removed rotating the interior handle forward felt a lot more positive but still no over-center that I could tell. I knew my top latch needed adjusting due to the wind noise so I started there. The upper latch assembly (#6) comes out as a unit, start by loosening the jam nut on the clevis (#24), then remove the small screws that holds the assembly in place, there are 2 machine screws that come in from the top. Care should be taken when removing the cotter, washer and clevis pin from #24, don’t drop them in the door. Once the latch assembly was out I got a better idea as how it all worked, item #18 is a stop, keeping it from going to far over-center. I turned # 24 2 full turns in (shorter) and re-installed the assembly (#6). I could now feel in the handle it going over-center but it was more pressure than I liked. Removing #6 and turning #24 in 2 more turns did the trick. The interior handle now has a positive lock and the outside handle fits nicely with the door. With the door closed and latched I wasn’t able to pry the top of the door away with my finger tips as before and it felt very secure.

 

                                                                       

 

The next thing was to look at the locks for the Cabin & Baggage doors. Ideally I want just 1 Key that works the Ignition and both door locks. I removed the lock assemblies from the doors but was unable to remove the cylinders to key them the same as the ignition. I stopped by a local Locksmith shop to see if they had any lock assemblies that could be keyed to my ignition key but they had just sold all 20 something they had in stock (figures). I stopped by Lowe’s to see what they had but no joy, Home Depot was my next stop and it was a score, Gate House # 0252974 looked like they would foot the bill but I wanted to make sure my original Bendix ign. key would fit the new locks. A clerk came by and asked if I needed help and told him I want to see if this key fit in that lock, he opened that package and the key went right in, plus the key cut was very close to mine. Once home I removed the cam which allowed the cylinder to be removed from the body. The way most locks work is the body of the lock has a keyway (these have 4) and the wafers/pins are spring loaded into that keyway, keeping the cylinder from turning (unlocking), when the key is inserted into the cylinder the cut of the key allows the wafers/pins to be pulled into the cylinder out of the keyway which allows the cylinder to turn. These were never meant to be re-keyed and the wafers were not removable. By inserting my ignition key in the cylinder I could see which wafers stuck up past the cylinder. The drawing below shows what I’m talking about. The wafers are brass and easily filed down to the radius of the cylinder allowing it to rotate in the body. Filing is done with the key inserted (fully), once they are filed down insert the cylinder with the key installed and check that it rotates freely in both directions completely. Once all the filing is done clean out all the metal filings and reassemble. I had to modify the cams to match the originals but its fairly straightforward looking at them side by side. Pay close attention to your old locks on orientation in the locked and un-locked positions, the new locks can be set by how the “Rotation Washer” is installed. Once I had both new locks keyed and correct (after a test fit & try) the cam is held on with a screw, which was removed and installed back with thread locker (loctite). As an added measure once the locks were in place and tightened I verified that they worked as needed, I then added several dabs of RTV on the nut/body/door skin and the screw/cam for safety. I now have 1 key that works the ignition switch and both door locks……..Hope I explained this well enough and if not shoot me a message and I’ll try to explain it better.

                              

 

Thank you, Rob. I used your method to replace main door lock that had no key. I used the same lock you mentioned  and I picked it up at Lowes. I inserted the old cargo hatch key and shaved off the excess from pins and then inserted the cylinder into old body. It worked great, but I think I might have shaved too much, because from the rattle of taxing the lock MAY have wobbled into lock position and locking me and co-pilot up inside the airplane, hahaha. Luckily, my wife was nearby and unlocked us. Another embarrassing story for FBO scuttlebutt. I will test this theory out again tomorrow and see if i just need.

Separately, I wonder if anyone developed a method to unlock the cargo hatch from inside. It seems like a good idea to have dual egress route. 

[carusoam]

9 minutes ago, ukrsindicat@yahoo.com said:

Thank you, Rob. I used your method to replace main door lock that had no key. I used the same lock you mentioned  and I picked it up at Lowes. I inserted the old cargo hatch key and shaved off the excess from pins and then inserted the cylinder into old body. It worked great, but I think I might have shaved too much, because from the rattle of taxing the lock MAY have wobbled into lock position and locking me and co-pilot up inside the airplane, hahaha. Luckily, my wife was nearby and unlocked us. Another embarrassing story for FBO scuttlebutt. I will test this theory out again tomorrow and see if i just need.

Separately, I wonder if anyone developed a method to unlock the cargo hatch from inside. It seems like a good idea to have dual egress route. 

Time to learn about your baggage door...

They all can be unlocked from the inside...

If not, there is a hardware kit that can be purchased... to perform the update...
 

Since the 90s the unlock for the baggage door is pretty well marked...

I refuse to lock it...  As if I believe in luck...  

There is probably a few threads that cover this issue...

Best regards,

-a-

[RLCarter]

46 minutes ago, ukrsindicat@yahoo.com said:

Thank you, Rob. I used your method to replace main door lock that had no key. I used the same lock you mentioned  and I picked it up at Lowes. I inserted the old cargo hatch key and shaved off the excess from pins.................. 

Well glad it worked (kinda) for you, it does sound like the cylinder is able to turn in the body with the key out. Definitely don't want that to happen..... If too much had to be removed it might be time to get a new set and start over 

[Ross Taylor]

Thanks @RLCarter for the detailed write-up.  I didn't change out my ignition, but I did change my door and baggage locks last year...so that they are now the same.  I put in barrel (round) locks, but the interior was the same as you described.  Now I'm down to just two keys. 

My interior door handle functions well and the overcenter seems right and secure.  But, I didn't quite dig enough into the mechanism (like you did) to understand the top latch.  My top latch is angled up enough that it's possible for it to slide over the top of the door frame (onto the painted "roof" if that makes sense).  The paint there is chipped and worn, so it's not a new issue.  Is there an adjustment for the angle or positioning of the upper latch, that you can describe for me?

Thanks!

Ross

[carusoam]

Ross,

The maintenance manual should have the adjustment technique for the door details...

They seam to get out of whack every decade or two...

Most PICs don’t allow anyone else to operate the door... too many variables to allow first timers to close the door and get it right...
 

Best regards,

-a-

 

[Mooney-Shiner]

40 minutes ago, RLCarter said:

Well glad it worked (kinda) for you, it does sound like the cylinder is able to turn in the body with the key out. Definitely don't want that to happen..... If too much had to be removed it might be time to get a new set and start over 

Thats fine, I haven't put all the trim together yet. Plus I will be applying foam under trim anyways. 

I hope that I'm wrong and the cylinder didn't spin locked without the key from engine vibration.

[Ross Taylor]

Thanks @carusoam - I'm with you on the door operation.  My wife is the only person, besides myself, who operates that now...and she knows what to watch for.  But the latch is clearly aggressively high and it's been over the top.  I'll look for instructions.  

[RLCarter]

@Ross Taylor I don't think there was an adjustment to keep the "hook" (top of door) from going over the top of the cabin. Sounds like it may have gotten bent some how