ITT Landing gear actuator overhaul/replacement?

[Nico1]

Looks like my ITT landing gear actuator on my 76 F is on its way out. In flight, retracting gear the CB tripped. Luckily putting selector down and pushing in CB lowered and locked the gear.

Plane was jacked and gear swings worked fine, though applying a little resistance on LG caused the CB to trip. My mechanic also said the noise it makes is unusual and lubrications looked ok. He suggests sending it out for overhaul. Problem is, are there any shops that do that? Called LASAR and they aren't doing it due to lack of parts. They suggested calling Pifer Aeromotors but cannot find their contact anywhere. Any suggestions are welcome!

[Marauder]

  On 11/9/2021 at 12:59 AM, Nico1 said:

Looks like my ITT landing gear actuator on my 76 F is on its way out. In flight, retracting gear the CB tripped. Luckily putting selector down and pushing in CB lowered and locked the gear.

Plane was jacked and gear swings worked fine, though applying a little resistance on LG caused the CB to trip. My mechanic also said the noise it makes is unusual and lubrications looked ok. He suggests sending it out for overhaul. Problem is, are there any shops that do that? Called LASAR and they aren't doing it due to lack of parts. They suggested calling Pifer Aeromotors but cannot find their contact anywhere. Any suggestions are welcome!

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Before you yank the motor, I would make certain that it is the motor. When my breaker was popping, it turned out to the a problem with the alternator and not the gear motor. Also, if the landing gear isn't rigged correctly or has not been properly maintained (built up grease sludge), the extra work can cause the breaker to pop. As well, those Klixon breakers do go bad and in the 31 years of ownership, I have replaced a number of them, including the gear breaker. 

I seem to recall George's in California was doing ITT motor rebuilds. I'll see if I can find their information in my logs.

[EricJ]

+1 to check the gear rigging first.   If something is binding it could be causing the drag on the motor that is making the breaker pop.

[Nico1]

  On 11/9/2021 at 3:03 AM, Marauder said:

Before you yank the motor, I would make certain that it is the motor. When my breaker was popping, it turned out to the a problem with the alternator and not the gear motor. Also, if the landing gear isn't rigged correctly or has not been properly maintained (built up grease sludge), the extra work can cause the breaker to pop. As well, those Klixon breakers do go bad and in the 31 years of ownership, I have replaced a number of them, including the gear breaker. 

I seem to recall George's in California was doing ITT motor rebuilds. I'll see if I can find their information in my logs.

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Thanks for the suggestions!

The LG doesn’t seem to be binding. Partially retracting the gear there looks like gear moves freely and all fittings are well lubed. 
 

discarded bad breaker: jpi shows amp draw of like 80 before it pops (its a 15A breaker). 
 

noticed that ITT actuator doesn’t have a fitting to grease like dukes does.. so wonder how to lube it correctly?

from reading the forums looks like George closed earlier this year  

Edited November 9, 2021 by Nico1

[JWJR]

There is a guy in Naples that specializes in Comanche gear. I think that’s the name of his website. He rebuilds dukes actuators and has 20:1 gears if you need them assuming you can’t get help from the Mooney sources. He also rebuilds the motors or has a good source that does. A call to him for advice might help. Google Comanche gear. Also Alan Fox has a itt actuator from a 76F one on eBay. I think he’s on Mooney space The add says working when removed.
Mine was serviced and all good however I’m considering buying another set of 20:1 gears now just to have on hand as future availability is in serious doubt.

[JWJR]

https://www.ebay.com/itm/Mooney-electric-gear-motor-and-transmission-from-76-C-Model-/113898808847?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0


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[Marauder]

  On 11/9/2021 at 3:16 PM, Nico1 said:

Thanks for the suggestions!

The LG doesn’t seem to be binding. Partially retracting the gear there looks like gear moves freely and all fittings are well lubed. 
 

discarded bad breaker: jpi shows amp draw of like 80 before it pops (its a 15A breaker). 
 

noticed that ITT actuator doesn’t have a fitting to grease like dukes does.. so wonder how to lube it correctly?

from reading the forums looks like George closed earlier this year  

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Hopefully one of the IAs will give you confirmation or the right answer but I believe the ITT needs to be disassembled to grease it. I would try to do a manual extension of the gear to make sure it is moving smoothly through the full extension. If the rigging is off or binding, it can pop the breaker. Also, keep in mind there are a number of relays in this gear circuit. There could be an issue with a relay causing that huge amp draw. 80 amps is a lot for a motor to pull without going up in smoke.

Speaking of the breaker... My breaker is a 20 amp breaker. I also have the ITT actuator in my 75 F. Wonder why they are different.

Here is the link to the service bulleting site: https://www.mooney.com/contact-2/#technical-publications

SB 189A shows a picture of the ITT installed.

[Nico1]

  On 11/9/2021 at 4:40 PM, Marauder said:

Hopefully one of the IAs will give you confirmation or the right answer but I believe the ITT needs to be disassembled to grease it. I would try to do a manual extension of the gear to make sure it is moving smoothly through the full extension. If the rigging is off or binding, it can pop the breaker. Also, keep in mind there are a number of relays in this gear circuit. There could be an issue with a relay causing that huge amp draw. 80 amps is a lot for a motor to pull without going up in smoke.

Speaking of the breaker... My breaker is a 20 amp breaker. I also have the ITT actuator in my 75 F. Wonder why they are different.

Here is the link to the service bulleting site: https://www.mooney.com/contact-2/#technical-publications

SB 189A shows a picture of the ITT installed.

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Thanks Marauder!

Manual extension worked smoothly. Voltage at motor up and down was fine, so unlikely a bad relay.

Looking at the original electric schematics for my s/n the breaker there is 15A. But look at SB 189A, there the breaker is 25A in the schematics (thought the description never mentions changing the breaker). weird...!

 

Edited November 9, 2021 by Nico1

[Nico1]

  On 11/9/2021 at 4:08 PM, JWJR said:

There is a guy in Naples that specializes in Comanche gear. I think that’s the name of his website. He rebuilds dukes actuators and has 20:1 gears if you need them assuming you can’t get help from the Mooney sources. He also rebuilds the motors or has a good source that does. A call to him for advice might help. Google Comanche gear. Also Alan Fox has a itt actuator from a 76F one on eBay. I think he’s on Mooney space The add says working when removed.
Mine was serviced and all good however I’m considering buying another set of 20:1 gears now just to have on hand as future availability is in serious doubt.

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Thanks! Will look into that

[EricJ]

  On 11/9/2021 at 4:40 PM, Marauder said:

Hopefully one of the IAs will give you confirmation or the right answer but I believe the ITT needs to be disassembled to grease it. I would try to do a manual extension of the gear to make sure it is moving smoothly through the full extension. If the rigging is off or binding, it can pop the breaker. Also, keep in mind there are a number of relays in this gear circuit. There could be an issue with a relay causing that huge amp draw. 80 amps is a lot for a motor to pull without going up in smoke.

Speaking of the breaker... My breaker is a 20 amp breaker. I also have the ITT actuator in my 75 F. Wonder why they are different.

Here is the link to the service bulleting site: https://www.mooney.com/contact-2/#technical-publications

SB 189A shows a picture of the ITT installed.

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I have a J and mine is 25A!   One difference on a J is the inner doors, which adds load, so that might explain that.   My understanding is that the motor is actually a high-current motor that is significantly derated for this application.   A momentary 80A draw at startup before popping the breaker may not be hurting the motor.

  On 11/9/2021 at 4:53 PM, Nico1 said:

Thanks Marauder!

Manual extension worked smoothly.

Looking at the original electric schematics for my s/n the breaker there is 15A. But look at SB 189A, there the breaker is 25A in the schematics (thought the description never mentions changing the breaker). weird...!

 

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What does the IPC for your airplane show for that breaker?   If you have the ITT actuator as described in the SB then the SB can be a basis for having the 25A breaker shown there.   FWIW, my airplane will reliably blow the 25A breaker if I try to retract the gear above about 90-95 kts, but I have the inner doors that add aero load.   If there is no binding and your wiring all looks healthy, that 15A breaker may be too small.  Consult your IA, but it may be worth just trying the larger breaker.

 

Edited November 9, 2021 by EricJ

[Nico1]

  On 11/9/2021 at 5:03 PM, EricJ said:

If there is no binding and your wiring all looks healthy, that 15A breaker may be too small.  Consult your IA, but it may be worth just trying the larger breaker.

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Thanks Eric! Will bring this up. Though this did not seem to be a problem before, so wonder what started to cause this now. I'm afraid it might not be addressing the cause ultimately.