Gear unsafe light

[BlueDun]

2 minutes ago, kortopates said:

Indeed it happens a lot more than you'd think. But these tubes aren't that hard to source from the factory, same tubes are used by many models and I've been able to get them in 2-6 weeks. In fact I don't  think it actually took upto 6 weeks.

Yes, and I suspect some owners don't know it and a fair number of mechanics don't notice the slight bend.

Anyway, the factory did help us and, once contacted, after the holidays last year, I think it took 4-6 weeks. We were originally told 20, if not in stock.

[Ragsf15e]

20 minutes ago, kortopates said:

Indeed it happens a lot more than you'd think. But these tubes aren't that hard to source from the factory, same tubes are used by many models and I've been able to get them in 2-6 weeks. In fact I don't  think it actually took upto 6 weeks.

Seems like one more reason to prefer a j bar.  Along with no Ad on the 40/1 gears, no airspeed switch and no impossible to find emergency crank cable.

How hard is it to convert one back? Mine was built with a j bar, modified at the factory after.

[EricJ]

20 minutes ago, Ragsf15e said:

Seems like one more reason to prefer a j bar.  Along with no Ad on the 40/1 gears, no airspeed switch and no impossible to find emergency crank cable.

How hard is it to convert one back? Mine was built with a j bar, modified at the factory after.

Pick your poison.   I've not heard of an electric gear system collapsing on the ground like the J-bars do.   These bent rods are a much cheaper fix. 

[N201MKTurbo]

[EricJ]

2 hours ago, N201MKTurbo said:

That gives you an idea of what's gonna give if the motor doesn't stop.   I wonder now if the motor didn't stop because the paddle was displaced or the paddle got displaced because the motor didn't stop.   

Also, that's a mighty fine-lookin' emergency gear cable you got there. 

[PT20J]

There seems to have always been a mechanical up stop. The mechanical down stop seems to be a feature added to the Eaton actuator. Not sure about the Plessey. The Dukes doesn’t appear to have a mechanical down stop. So I guess if the down limit switch fails, you get bent tubes. 

[kortopates]

There seems to have always been a mechanical up stop. The mechanical down stop seems to be a feature added to the Eaton actuator. Not sure about the Plessey. The Dukes doesn’t appear to have a mechanical down stop. So I guess if the down limit switch fails, you get bent tubes. 

It’s a very fine line between compressing the springs to get the required pre-load and fully compressing the springs. I recall the MM calling for 1/4 to 3/8” gap in adjusting the mechanical down stop. That’s a big enough gap that when the limit switch fails it could still fully compress the springs and bow a tube.
Because of the geometry, the left tube will be first to bow so you won’t necessarily loose both tubes. plus limit switches don’t necessarily fail completely but may require further throw and pressure to close.


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[T. Peterson]

On 12/23/2023 at 7:41 AM, Kerrville said:

I need to pull everything apart now. Can’t find parts. Another airplane for the scrap heap?  

Several have recommended that you call one of the Mooney Centers. Since Don Maxwell is only an hour away I would call him. I believe he will have a workable solution and it won’t include scrapping the plane. But in this case you must call. He has ways of sourcing parts well beyond our capabilities, but can’t help at all if you don’t call. Mooneyspace is a wonderful resource but in this case you need more. 

[PT20J]

2 hours ago, kortopates said:

It’s a very fine line between compressing the springs to get the required pre-load and fully compressing the springs. I recall the MM calling for 1/4 to 3/8” gap in adjusting the mechanical down stop. That’s a big enough gap that when the limit switch fails it could still fully compress the springs and bow a tube.
Because of the geometry, the left tube will be first to bow so you won’t necessarily loose both tubes. plus limit switches don’t necessarily fail completely but may require further throw and pressure to close.


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According to the M20J Service Manual, for the Eaton style actuator, the distance between the ball screw barrel nut and the mechanical stop when the gear is down should be .050 - .100 inches. I'm not sure what that translates to in linear motion of the retraction rods -- depends on the mechanical advantage of the bell crank -- but I doubt the rods would get bent if everything were adjusted correctly and the down limit switch failed. The manual allows up to a 325 in-lb preload torque when the gear is electrically lowered (this is higher than the 250 - 280 in-lb when manually lowered to allow for some overrun). But, if it is true, as it appears to be, that there is no mechanical down stop on a Dukes actuator, then a failed down limit switch and resulting overrun would bottom out the bungee springs out at the gear wells. When setting up the gear, the starting preload on the springs is set by only two turns of the rod ends on the retraction tubes -- not much linear distance.

Skip

[201Mooniac]

BTW, @Alan Fox is parting out a 1983 M20J, he might have the tubes you need.

[1980Mooney]

@Kerrville  This salvage fuselage may still have what you need.

https://azairsalvage.com/product/1978-mooney-m20j-3538-9-aftt-lycoming-io-360-a3b6d-776-smoh-project-aircraft/

[Alan Fox]

3 hours ago, 201Mooniac said:

BTW, @Alan Fox is parting out a 1983 M20J, he might have the tubes you need.

Yes I have the tubes , in all flavors... 

[Kerrville]

Sent a message to Alan. Some have mentioned the factory. I thought it was out of business.  

[EricJ]

7 minutes ago, Kerrville said:

Sent a message to Alan. Some have mentioned the factory. I thought it was out of business.  

They still make parts.    If there's an airframe part that you can't find, they may have it or be able to make it.   Usually you go through an MSC, i.e., ask an MSC for the part number.   IIRC the factory also has an MSC on-site that does annuals and such things, so you may be able to ask them for the part.   Lead times may be long if they don't have one laying around.

[PT20J]

Factory service center does maintenance and repairs but does not sell parts. The only way to get new parts from Mooney is through a MSC. 

Frank Crawford will verify parts numbers and Mooney stock, but not parts pricing since each MSC sets its own markup. 

[Kerrville]

19 minutes ago, PT20J said:

Factory service center does maintenance and repairs but does not sell parts. The only way to get new parts from Mooney is through a MSC. 

Frank Crawford will verify parts numbers and Mooney stock, but not parts pricing since each MSC sets its own markup. 

Unfortunate. 

[Alan Fox]

I have had gear doors on order for over 18 months , Intake boots and no back springs on order for over a year , Good luck waiting on the factory...

 

[Pinecone]

1 hour ago, Alan Fox said:

I have had gear doors on order for over 18 months , Intake boots and no back springs on order for over a year , Good luck waiting on the factory...

 

Intake boots and no back springs are not made by the factory.  They need to get enough orders to order a batch.  IIRC, the minimum order from Eaton for the NBS is 50.

[PT20J]

1 hour ago, Kerrville said:

Unfortunate. 

Mooney has not sold parts direct for 30 years.

[LANCECASPER]

2 hours ago, Kerrville said:

Unfortunate. 

General Motors doesn’t sell parts to customers. You go through a GM dealer.

[1980Mooney]

1 hour ago, LANCECASPER said:

General Motors doesn’t sell parts to customers. You go through a GM dealer.

Actually they do….Direct….No Dealer - no middleman. You have the option of having the parts delivered to your home or a dealer if you want. 
 

https://www.freep.com/story/money/cars/general-motors/2022/01/18/gm-parts-sale-online/6562278001/

https://www.caranddriver.com/news/a38819559/gm-maintenance-repair-parts-online-selling/#

https://www.gmpartsdirect.com
 

 

 

[LANCECASPER]

1 hour ago, 1980Mooney said:

Actually they do….Direct….No Dealer - no middleman. You have the option of having the parts delivered to your home or a dealer if you want. 
 

https://www.freep.com/story/money/cars/general-motors/2022/01/18/gm-parts-sale-online/6562278001/

https://www.caranddriver.com/news/a38819559/gm-maintenance-repair-parts-online-selling/#

https://www.gmpartsdirect.com
 

 

 

Ok bad example on my part - GM never used to do that. They respected their dealers.

Mooney has no ability to sell parts individually to 7000 Mooney owners. +/- 50 Mooney Service Centers is a stretch.

Your third example however,  Gmpartsdirect.com is a dealership in Winston-Salem NC.

[1980Mooney]

2 hours ago, LANCECASPER said:

Ok bad example on my part - GM never used to do that. They respected their dealers.

Mooney has no ability to sell parts individually to 7000 Mooney owners. +/- 50 Mooney Service Centers is a stretch.

Your third example however,  Gmpartsdirect.com is a dealership in Winston-Salem NC.

Good point. It is hard to tell who one is buying from.  So GM sells parts direct ....competing with dealers....and then dealers set up websites that look like "GM Diret".....competing with GM's direct parts sales.  I wonder if GM retaliates against the dealer behind "Gmpartsdirect"?!  

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[Kerrville]

IA said that I should test this down limit switch. There are 6 wires coming from it. Any ideas on how to check its proper operation. Looks like a bit of a pain to remove, so I’m thinking the best way to check it may be simply to press it once it’s up on jacks and see if it works.

 

if I go the multimeter route, does anyone know how I can identify which wires should show continuity or not based on switch position?

[KSMooniac]

You'll need to get the wiring schematic from the service manual for your serial number, and then trace the wires in the schematic.  From the schematic, you can see where the wires go, and hopefully find a connector that you can disconnect and use a multimeter there.  I don't know if these have power applied directly, but if so, you might need to use a power supply to power it while you have it disconnected.