Question Landing Gear Actuator

[charlesual]

I have a M20F with the Vikers 20:1 actuator and I came across a Dukes 40:1 that I thought would be a nice upgrade. Is there any reason I should or should not put the Dukes in?

 

 

 

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[KSMooniac]

I would get the Dukes serviced/inspected and then put it in.  Save the other for an emergency spare.  Triple-check the emergency crank system...especially thes spline drive that goes into the gear box!  Mine failed years ago and that would have left me with the gear stuck up if my motor failed.  (My motor failed in year two of my ownership period too, but fortunately that spline worked in that instance!)

[DCarlton]

2 hours ago, KSMooniac said:

I would get the Dukes serviced/inspected and then put it in.  Save the other for an emergency spare.  Triple-check the emergency crank system...especially thes spline drive that goes into the gear box!  Mine failed years ago and that would have left me with the gear stuck up if my motor failed.  (My motor failed in year two of my ownership period too, but fortunately that spline worked in that instance!)

Would be curious to know who services or overhauls these too.  

[N201MKTurbo]

It should just work. As said above, make sure your emergency extension crank works with this actuator. I would pull the gearbox's apart, clean them and inspect the gears and repack with fresh grease. Remember the grease is a special mix of grease and MDS. I would pull the brushes and see how much life they have. You will need to chip off the epoxy seals on the brushes. I would reseal them with a dab of RTV instead of epoxy. I have seen the epoxy fall off. Other than that make sure the polarity is correct so it runs the right way.

[charlesual]

Thanks all. Very helpful. As an alternative, would it be better to swap the 20:1 for 40:1 gears in the Vickers actuator? The Vickers does seem more robust (and heavier)


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[PT20J]

I'm confused. Are those pictures of the Vickers that was removed and the Dukes you are considering installing?  The Vickers in the picture is not a 20:1 gear actuator. It is a later model design as used in airplanes built after 1978. It has been built under various names: Avionics Products, Vickers, Eaton. It has a more robust gear train and has a noback spring and a completely different emergency gear extension mechanism than the Dukes. I believe that parts for the Dukes emergency gear extension system are difficult to obtain.

[charlesual]

I'm confused. Are those pictures of the Vickers that was removed and the Dukes you are considering installing?  The Vickers in the picture is not a 20:1 gear actuator. It is a later model design as used in airplanes built after 1978. It has been built under various names: Avionics Products, Vickers, Eaton. It has a more robust gear train and has a noback spring and a completely different emergency gear extension mechanism than the Dukes. I believe that parts for the Dukes emergency gear extension system are difficult to obtain.

Now I’m really curious. There’s no logbook entry on the Vickers so I assumed it was original. You can tell by looking at the Vickers and see it’s already a 40:1? Is there a way to verify or count the rpm’s? That would really solve a lot of problems. Thanks!!


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[jetdriven]

I don't know what the ratio is, but there were a few M20F's that were built at the factory like that with the pull thing in the floor and everything. We have one we take care of like that, even has the corrugated J style elevators, but it's a 75 airplane. Now 76's and 77's didn't have that but 78 did. its almost like they wanted to  try it out for a while.

[Matthew P]

Do, there is an AD for the Dukes actuator but not for the Vickers from what I understand, regardless, you CANNOT find replacement gears for those things regardless of 20:1 or 40:1 gearsets, Mooney is REFUSING to have anymore made for its customers, my suggestion would be to put the original back in the aircraft, keep the Dukes as a spare...at some point you will either need the motor or the gears or both, Don't know of anyone who rebuilds the motors of any of them anymore.

 

Interesting tidbit, the landing gear actuators in the newer Mooneys, the ones they have parts for, should fit in the older ones, but the newer ones are 24v, not 12v, which isn't necessarily a problem depending on how many amps it draws, could always get a step up converter from 12vdc to 24vdc if 10amps or less..when I asked Mooney about it, I asked if they use the same gears, thinking that might be a way to get them, they didn't have an answer for me.

 

 

Edited June 20 by Matthew P

[PT20J]

1 hour ago, charlesual said:

You can tell by looking at the Vickers and see it’s already a 40:1?

The 20:1 / 40:1 ONLY applies to the Dukes (and similar ITT) actuators which use a worm and wheel gear arrangement. The problem with them is that the gears are small and heavily loaded. The moly grease helps reduce friction and thus wear, and the 40:1 retrofit gears are less heavily loaded than the original 20:1 gears to further reduce wear. Eventually the gears will wear out and there are currently no replacement parts available.

The Eaton (a.k.a Avionics Products, Vickers) and the similar Plessey actuators use a spur gear train that is less heavily loaded and I have not heard of issues with gear wear on these actuators. 

The Mooney electric gear has no mechanical up locks. Something has to keep the gear from falling back down when in the retracted position. The worm and wheel gear arrangement cannot be back driven, so the Dukes/ITT actuators naturally hold the gear retracted. But the spur gear arrangement on the Eaton/Vickers actuator needs a brake which is the infamous noback spring.

There have been a handful of noback spring failures in the field, most in Plessey actuators. There was one bad batch of Eaton noback springs that was recalled long ago and probably none exist in the field today. Don Maxwell told me that the Eaton noback spring is rated for 20,000 cycles. The 1000 hour replacement interval seems arbitrary and chosen because of a couple of failures or Plessey springs at around that time in service. But, time in service is meaningless. It is cycles that is important. Currently there are no new noback springs available.

If it were my airplane,  I'd keep the Vickers because I believe its a more robust design. It would also probably be a lot of work to source the parts and switch to the Dukes emergency retraction crank system.

[DCarlton]

1 hour ago, PT20J said:

The 20:1 / 40:1 ONLY applies to the Dukes (and similar ITT) actuators which use a worm and wheel gear arrangement. The problem with them is that the gears are small and heavily loaded. The moly grease helps reduce friction and thus wear, and the 40:1 retrofit gears are less heavily loaded than the original 20:1 gears to further reduce wear. Eventually the gears will wear out and there are currently no replacement parts available.

The Eaton (a.k.a Avionics Products, Vickers) and the similar Plessey actuators use a spur gear train that is less heavily loaded and I have not heard of issues with gear wear on these actuators. 

The Mooney electric gear has no mechanical up locks. Something has to keep the gear from falling back down when in the retracted position. The worm and wheel gear arrangement cannot be back driven, so the Dukes/ITT actuators naturally hold the gear retracted. But the spur gear arrangement on the Eaton/Vickers actuator needs a brake which is the infamous noback spring.

There have been a handful of noback spring failures in the field, most in Plessey actuators. There was one bad batch of Eaton noback springs that was recalled long ago and probably none exist in the field today. Don Maxwell told me that the Eaton noback spring is rated for 20,000 cycles. The 1000 hour replacement interval seems arbitrary and chosen because of a couple of failures or Plessey springs at around that time in service. But, time in service is meaningless. It is cycles that is important. Currently there are no new noback springs available.

If it were my airplane,  I'd keep the Vickers because I believe its a more robust design. It would also probably be a lot of work to source the parts and switch to the Dukes emergency retraction crank system.

The best summary I’ve seen on the subject.  Thanks.  

[charlesual]

Love Mooneyspace!!


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[Nico1]

9 hours ago, Matthew P said:

Do, there is an AD for the Dukes actuator but not for the Vickers from what I understand, regardless, you CANNOT find replacement gears for those things regardless of 20:1 or 40:1 gearsets, Mooney is REFUSING to have anymore made for its customers, my suggestion would be to put the original back in the aircraft, keep the Dukes as a spare...at some point you will either need the motor or the gears or both, Don't know of anyone who rebuilds the motors of any of them anymore.

Any updates from Mooney after collecting interest for the 40:1 gears? Wonder what their response will be!

[Matthew P]

1 hour ago, Nico1 said:

Any updates from Mooney after collecting interest for the 40:1 gears? Wonder what their response will be!

Silence, awaiting a call from CEO, Mr. Pollack...

[Nico1]

10 minutes ago, Matthew P said:

Silence, awaiting a call from CEO, Mr. Pollack...

Fingers crossed! And thanks so much for coordinating this! 

[1980Mooney]

On 6/19/2024 at 1:15 PM, charlesual said:

 

I have a M20F with the Vikers 20:1 actuator and I came across a Dukes 40:1 that I thought would be a nice upgrade. Is there any reason I should or should not put the Dukes in?

 

 

 

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If you look closely at the motor on your installed landing gear actuator, it looks like it was manufactured in 1978,  This appears to be an early version of the Avionics Products Company actuator, Serial number 817.  That actuator is superior to the Dukes,  as @PT20J highlighted.   Mooney dropped the Dukes and started using the Avionics Products Company actuator as standard in 1977 starting on the M20J with serial number 24-0378.  Avioncis Products Company, via corporate sales and dispositions, eventually became the Eaton actuatror. (see below).

However, you also have a Vickers label on it without any model number or serial numbers and a "Clutch Spring Replacement" label (that is the "No Back Spring").  I think that you have a unit that was overhauled by Vickers.  And since Eaton bought Vickers in 1999 and combined it with its Avionics Products Company (Division of Consilidated Controls) after that date, this was likely overhauled after 1999.  I would bet that this was installed in your plane in 2000 or after.

• Avionics Products Company (Denville, NJ) was owned by Consolidated Controls Corporation (CONDEC)
  • Avionics Products Company sold actuators to Mooney labeled under the name Avionics Products Company (Denville, NJ) 
    • Some are just labeled CONDEC - Consolidated Controls Corp. 
• Consolidated Controls Corporation (CONDEC) was purchased by Chicago industrialist Farley in 1984.
  • The acquisition went badly for Farley and Farley sold CONDEC to Eaton in May 1986.
    • So in 1986 Eaton inherited Avionics Products Company actuators - they changed the labeling at some point to Eaton.
      • I have seen some labeled with Eaton Valve and Actuator Div. (El Segundo, CA)
• In 1984, Libbey-Owens-Ford (L-O-F) acquired Vickers Inc., a leading maker of hydraulic and electrohydraulic systems, from the Sperry Corporation. (no relation to the Vickers PLC (UK).  L-O-F combined Vickers with Aeroquip, which they had purchased in 1968 and renames it Aeroquip-Vickers
  • In 1999 Eaton acquires Aeroquip-Vickers
    • The Vickers Aerospace Actuators and Controls Div.is located in Grand Rapids, Michigan.
      • There are Mooney actuators labeled with only the Vickers name (Vickers Aerospace Actuators and Controls Div.- Grand Rapids, Michigan)
  • It is not clear if Vickers made any actuators before the Eaton takeover.  More likely Eaton consolidated all Mooney landing gear actuator manufacturing in the Vickers division.  However, the actuators labeled with "Vickers" do no say that they are a division of Eaton.

[ArtVandelay]

Mine is very similar, same labels, except my Vickers sticker has the pertinent information stamped on it and my clutch spring has been replaced 3 times, also stamped, 3rd time it was done by Lasar I think, just after I bought the plane (it’s emergency extension cord jammed).

[charlesual]

You guys are truly amazing!

To sum it up I have a:

-Eaton actuator probably manufactured in 1978. S/N 817 (which is superior to the Dukes)

-evidently overhauled by Vickers with a Clutch spring replacement (no back spring) which has a spur gear system (less heavily loaded and more robust) and not a 20:1 installed 2000 or after.


Couple more questions?

-Since it’s not a 20:1, what is it?

- apparently there are better labels available for this actuator. Should I send it out for overhaul with updated labels? Eaton or Lasar?

-With the Eaton actuator, could I add the inner gear doors?

Lastly, since I’m now all in on the Eaton actuator, I have a spare 40:1 dukes actuator (which appears to be the same as my flap actuator)

-should I hold onto it as a spare or sell it and how much is it worth?

Hope I get to meet some of you guys at the upcoming Mooney summit. I’d love to buy you a sparkling beverage.


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[EricJ]

32 minutes ago, charlesual said:

-Since it’s not a 20:1, what is it?

It'll be either 20:1 or 40:1.    

[1980Mooney]

2 hours ago, charlesual said:

Couple more questions?
-Since it’s not a 20:1, what is it?
- apparently there are better labels available for this actuator. Should I send it out for overhaul with updated labels? Eaton or Lasar?
-With the Eaton actuator, could I add the inner gear doors?
Lastly, since I’m now all in on the Eaton actuator, I have a spare 40:1 dukes actuator (which appears to be the same as my flap actuator)
-should I hold onto it as a spare or sell it and how much is it worth?

Dukes? no idea of value. - what is the condition- Used on eBay, Overhauled, Yellow tagged?  On eBay people are asking $6,000 for used Eatons of unknown condition.  The Eaton is superior to the Dukes.  It was installed right up to the end - of course since mid-80s it was 28v.  Yes Eaton actuators can handle inner gear doors.

[1980Mooney]

@charlesual

Also @Fritz1 posted this - "the dukes actuator is known to be undersized for the job".