Gear won’t swing

[Jocbay]

78 J model. Last week in the pattern. I lowered the gear and the the gear down light on the floor didn’t illuminate. The circuit breakers for both the gear actor and gear down light were popped.   Ammeter showed normal. I followed the emergency gear down procedure and was only able to move the t-handle 6”.   Long story short, after several low passes, the gear was confirmed down and I landed without incident. 
We have it up on jacks and get this.  Both circuit breakers in, and gear won’t raise.  Don’t hear the gear motor. Gear safety bypass light  and horn come on when we put the gear handle up.  When we push the gear safety bypass button it trips the 15 amp gear actuator cb. 

A&P and I are hoping for help from the ms brain trust. Thanks 

[A64Pilot]

I’d disconnect the motor and see if it still trips. if it doesn’t, then I’d suspect the motor or actuator binding, if it trips with the motor not connected then of course you have a short.

However your story of having difficulty getting them down manually seems to point to a mechanical problem, unless they were almost fully down when the problem occurred.

How old is the no back spring?

On edit I don’t have a lot of Mooney experience, this was just general troubleshooting and the question about that spring was just out of curiosity more than anything 

 

Edited August 14, 2021 by A64Pilot

[Jocbay]

Most appreciated a64. Upon further inspection, we believe the cable or the clutch is bound. The t handle is tight and will not move even a fraction of an inch.  As u might guess the whole clutch assembly has very tight access.  We are off to do some research. Laser was recommended as an info source, but of course it’s Saturday. Here’s a pic if the gear assembly.  I believe we will be dealing with everything aft of the silver colored gear motor. 
There is a spline inside the conical part with the cap on it  anyone know it’s purpose?

[Jocbay]

There is a spline inside the conical part with the cap on it  anyone know it’s purpose?

im guessing the no back spring is original. 

[Yetti]

The spine gear is the emergency down cable.  It is speedometer cable so you don't go backwards with it.

The gear will be in tension down due to overcenter locks.

STart with lubing all the gear.

Pull gear actuator and lube it

The boden cable is your e gear actuator.

Put a vom or test light on the relays and make sure power is going.

Mine started working just fine after a good lube.   Been working for 4 years.

Make sure you get all the shims right in the actuator.  ie take pictures.

you are going to need a ground down socket 7/16 to get to one of the bolts.

[EricJ]

Could be a faulty relay, too.   The circuit that is popping the breaker has an overcurrent (e.g., short) condition somewhere, which could be an exposed wire, loose connector contacting surrounding ground, etc.   Should be able to isolate it by disconnecting things sequentially along the circuit.    Starting at the motor isn't a bad idea.   You can also see if the gear/actuator is mechanically jammed and preventing the motor from turning.

 

[ArtVandelay]

I’m the same year, I don’t know how much it matters but you seem to be missing a spring:



I’d fixed that first before you do anything.
It also looks like it has been serviced only once, you’ll notice mine has been serviced 3 times. Might be a good time to have it overhauled.

[PT20J]

I believe that spring keeps the emergency extension clutch mechanism fully disengaged. Full engagement will jam the motor and pop the breaker. Partial engagement may allow the the motor to chew up the clutch mechanism. 

If it were mine, I wouldn’t trust it until it had been IRAN’d. Any issue with the motor, gearbox, or clutch that can prevent the jack screw from rotating will prevent lowering the gear by any means.

Glad you were able to get it down and land safely.

Skip

[Guest]

8 hours ago, john buhrman said:

78 J model. Last week in the pattern. I lowered the gear and the the gear down light on the floor didn’t illuminate. The circuit breakers for both the gear actor and gear down light were popped.   Ammeter showed normal. I followed the emergency gear down procedure and was only able to move the t-handle 6”.   Long story short, after several low passes, the gear was confirmed down and I landed without incident. 
We have it up on jacks and get this.  Both circuit breakers in, and gear won’t raise.  Don’t hear the gear motor. Gear safety bypass light  and horn come on when we put the gear handle up.  When we push the gear safety bypass button it trips the 15 amp gear actuator cb. 

A&P and I are hoping for help from the ms brain trust. Thanks 

Check that you didn’t overextend the gear and run the ball nut on the actuator into full contact with the actuator.  This would lock the gear not allowing it to retract.

Clarence

[A64Pilot]

I’d still disconnect the motor and ensure the CB doesn’t pop and if it doesn’t check for voltage, I bet there will be and something mechanical has the motor bound up, but that’s just my guess. Unfortunately I don’t believe the motor brushes are replaceable, or I’ve been told they aren’t anyway.

Being as I don’t trust myself enough to overhaul the actuator myself, I’d send it to LASAR.

‘I don’t have the belly pan off of mine, but I can confirm the presence of a spring, that you don’t seem to have. 81 model J

If I understand the system, the emergency gear extension will only operate if there is an electrical fault, any mechanical fault and your not getting the gear down, that’s why I wouldn’t attempt to overhaul / service the actuator myself, no room for error.

I don’t know if no back springs are available or not, if you call and hear they are send me a PM please or post as I need to get one in hand as apparently they sell out quickly and there are gaps when they aren’t available, I think they are $1,000 for a little spring, but what option do you have?

I’ve not bought one, nor have I ever had my actuator out, heck I’ve only owned a Mooney for a few months, but I plan on having the actuator gone through this annual.

But if it’s what I think it is, you ought to go out and buy a Lottery ticket, because you did indeed get lucky.

But then I only think I know how the system works, I’ve only dug into the electrical half myself so far.

Edited August 15, 2021 by A64Pilot

[Ragsf15e]

On 8/14/2021 at 9:19 AM, john buhrman said:

78 J model. Last week in the pattern. I lowered the gear and the the gear down light on the floor didn’t illuminate. The circuit breakers for both the gear actor and gear down light were popped.   Ammeter showed normal. I followed the emergency gear down procedure and was only able to move the t-handle 6”.   Long story short, after several low passes, the gear was confirmed down and I landed without incident. 
We have it up on jacks and get this.  Both circuit breakers in, and gear won’t raise.  Don’t hear the gear motor. Gear safety bypass light  and horn come on when we put the gear handle up.  When we push the gear safety bypass button it trips the 15 amp gear actuator cb. 

A&P and I are hoping for help from the ms brain trust. Thanks 

This scares me.  The gear isn’t that complicated, but it’s just complicated enough and requires some special tools to check… I can see mechanics not familiar with it setting it up wrong, destroying the gear motor, or having no idea how to troubleshoot it.  Could all be while you’re stuck away from home.

At least the engine is pretty much the same as others in the current fleet.  Flight controls are similar too…

Edited August 15, 2021 by Ragsf15e

[Yetti]

1 hour ago, Ragsf15e said:

This scares me.  The gear isn’t that complicated, but it’s just complicated enough and requires some special tools to check… I can see mechanics not familiar with it setting it up wrong, destroying the gear motor, or having no idea how to troubleshoot it.  Could all be while you’re stuck away from home.

At least the engine is pretty much the same as others in the current fleet.  Flight controls are similar too…

It's not a complex system.  

https://youtu.be/CL_yO7fKhh8

 

[sleeper-319]

While doing gear swings during the pre buy inspection, we cycled the emergency/manual gear deployment (hadn’t been exercised in many years). When I lifted the t-handle, the cable adjuster screw slipped a little bit and slackened the actuator cutoff just enough, and it resulted in exactly the symptom you’re having.

This cable adjuster screw is right at the spot where @ArtVandelay says you’re missing a spring (although it’s obscured slightly in his photo). 

We have different actuators and different emergency gear deployment setups, so this may not be related to your situation at all, but figured I’d mention it if you’re still troubleshooting. Easy to check. 

 

 

[A64Pilot]

I’m going to throw out one possibility, gear functioned normally and extended fully, but an open circuit in the down limit switch didn’t turn off the actuator so the CB’s popped.

Then as M20Doc said using the manual system bound up the gear, as evidenced by the emergency cable only moved 6” or so, maybe just enough to bind the system up.

The missing spring would have me concerned though, because while I have never disassembled an actuator it’s logical that it’s purpose is to hold the clutch completely disengaged.

All speculation of course

[ArtVandelay]

It’s far overdue to be serviced, no matter what, I’d have it overhauled.
Obviously I get a new spring, probably get that from overhaul shop.
While it’s shipped off, I’d manually checked all limit switches and motor relays, and manually swing the gear to check that it’s not binding.
Landing gear is not something that can be “probably Okay”.

[A64Pilot]

1 hour ago, ArtVandelay said:

Landing gear is not something that can be “probably Okay”.

https://youtu.be/EMgA-y2nRWE

[Jocbay]

Pulled this bundle of joy today. Took me and my mechanic about 2 1/2 hrs to get it out.  An offset 5/8” open end wrench (which we didn’t have) would make it go much faster.  Now it’s off to Lasar.  Gear swings with no binding so I guess I’m making progress. 

[carusoam]

Nice gear actuator pic John!

Do the decals give any hint of service history or anything?

Just not enough resolution to see it from here…   

Best regards,

-a-

[Jocbay]

Nope, no record of service on the unit.