Gear Breaker Pops

[dfgreene61]

My M20J has been popping the gear breaker on gear up when it's under 30F.  Never happens when it's warm.  The breaker pops just before the gear is full up.  Resetting the breaker completes the cycle and all is well.  ideas?

 

[DVA]

Sound like a high resistance popping, since I assume that the only time it is happening is right before the gear is fully up.

My guess is that there is either 1) a binding of the mechanical system right at that point in the swing that causes the gear motor to struggle enough to cause a high current and thus popping the breaker, or 2) you have a getting-bad gear motor.  I tend to go to the former as a hypothesis based on your comment that it only happens in cold weather. The cold will tighten everything up and if the articulating points are dirty and have old grease, they can get very reluctant to move in the cold.

 

[Hank]

When were your pucks changed last? In my C, in cold weather the gear would often not raise the last little bit, and the squall in my headset was terrible. The next summer, everything was great, then the next winter it started again, worse than before. Replaced pucks in December, everything worked like it was supposed to, my landings improved and taxiing was more pleasant.

FYI, the month and year that the landing gear pucks were made is molded into the edge. If they're over ten or twelve years old, think about replacing tbem.

[N201MKTurbo]

What kind of actuator do you have?

The actuator is telling you it is sick and needs attention.

[75_M20F]

That was happening to my M20 F a few years back. It turned out to be the electric gear motor was worn out. Mechanic sent it out to be overhauled and it has been fine since.

[jclemens]

Most likely the gear motor is in need of replacement, as others have mentioned.

[jdrake]

Very timely post.  Last weekend a friend experienced a similar situation with his 84 J.  IIRC it was the gear relay breaker that would open whenever gear up was selected.

In his case, the plane was in for annual and on jacks in a warm climate.  After scouring the gear bay for obvious faults and finding none, he accidentally discovered that the condition only happened when the glare shield was installed.  After some detective work and consultation with a knowledgeable Mooney A&P they narrowed the search to instrument panel.  Yes, the panel.

Generally speaking, there are two "panels" where instruments and radios are mounted - I don't know the technical name so let's refer to them as the subpanel and the façade that faces the pilot positions.  In his case, the façade is mounted to the subpanel using rubber mounts that dampen vibration.  I think of them like very small engine mounts.  Over time, these mounts lose their flexibility and allow the façade to sag.  In my friend's case, when the glare shield was removed, the gear behaved perfectly.  However, when the glare shield was installed, it exerted just enough downward pressure on the metal façade that it came in contact with electrical components (I think around the switch bus).  When gear up was selected, there was a spike in amperage as would be expected with a direct short and the breaker opened.

This may or may not be helpful in your case but I certainly found it to be a learning experience and hope others do to.

[mooney2201]

friend of mine had the same problem,turned out to be heim bearings dry on nose gear door..that was it, just a little oil..amazing !!!!!!!!

[dfgreene61]

Thanks for responding everyone.  I'll print this out and give it to my mech.

[Yetti]

Lube all 10000 zerks in the main and nose gear.   Should also lube the actuator.   Put it on jacks to lube the gear it makes the grease go in easier.

[NotarPilot]

Doesn't the latch on the emergency gear release lever make the CB pop if it's not locked into place? I seem to remember that happening to me once.

[ArtVandelay]

Doesn't the latch on the emergency gear release lever make the CB pop if it's not locked into place? I seem to remember that happening to me once.

Yes but OP said it doesn't happen when warm.

[dfgreene61]

It's not the em gear release, I learned that lesson shortly after buying my J.  Added checking the release as part of my pre-flight.