How many hours before overhaul of landing gear mechanism?

[RobertE]

I'm completely up to speed on the no back spring clutch issue and am also aware of the need to change brushes in the motor after what sounds like about 3,500 hours to be prudent.  

Mine has 3500 on the motor and all the rest of the assembly and 2000 hours on the spring so I'm going to have the motor overhauled and spring replaced soon (like many of you I'm a little concerned about infant mortality on the new spring but figure 2000 hours sort of splits the difference between 1000 recommended and never. I'll report to this forum the condition of the old spring when I inspect it) so my question concerns the rest of the mechanism.  Should I have the jackscrew and everything else done at the same time?

[carusoam]

Robert,

There is a thread around here somewhere where we covered the number of hours that that motor actually runs in your life time.  

The calculation was based on the length of time it runs per activation and the number of activations per flight, flights per year and the years of ownership...

It hardly gets used at all, hardly enough time to wear out the brushes.  But all things are possible with how old they are...

Best regards,

-a-

[Hank]

It never hurts to clean the trim jackscrew and get rid if all the old, hard grease. A recent thread recommended cleaning chain on the trim mechanism, too. I'd be shocked if there is significant wear on the brushes.

[Joe Larussa]

My 77 201 had about 3800 when my gear got stuck partially up. When we pulled the motor there was nothing left of the brushes. Only the springs that hold them in!

[ArtVandelay]

7 hours ago, Joe Larussa said:

My 77 201 had about 3800 when my gear got stuck partially up. When we pulled the motor there was nothing left of the brushes. Only the springs that hold them in!

This reinforces what Robert said, 2000 probably a good max, I would use 1000 if the plane is subject to pattern work.

[ArtVandelay]

Does the actuator require any service at annual? Lube? What about flaps actuator?

[Seth]

I'll have to check my logbooks to see if the spring was done on my aircraft.  I'll have to check.  What is the price of a new spring?

 

-Seth

[RobertE]

The kit is about $800 and I've been quoted another $1,200 in labor at Lasar, for $2K in total.  Amazing how costly a little spring can be, eh?

[carusoam]

Joe has a nice data point for how long the brushes last on the gear motor that doen't get a lot of time....

Best regards,

-a-

[Godfather]

1 hour ago, carusoam said:

Joe has a nice data point for how long the brushes last on the gear motor that doen't get a lot of time....

Best regards,

-a-

I wonder if it's the 40 years or the number of cycles?  If the armature started forming rust it might use up the brushes very quickly.

[carusoam]

GF,

I know of the one data point...

A few weeks ago, we calculated the total time that motor actually runs by seconds per cycle and cycles per flight and flights per year.  It is in the realm of a few hours per decade... Surface Oxidation and dirt are possibly large factors in this wear...

Best regards,

-a-

[Seth]

On April 2, 2016 at 0:35 PM, RobertE said:

The kit is about $800 and I've been quoted another $1,200 in labor at Lasar, for $2K in total.  Amazing how costly a little spring can be, eh?

Wow.  Makes me think of Bonanza parts!!  Kidding, kind of, the Bo is a good airplane.

I'll bring it up to my shop and again need to check the logbooks.

-Seth