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MB65E

Changing the AFT most rudder idler bushing?

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So I'm debating changing the bushing in the aft most rudder idler in the tail cone.  The play in the system is otherwise tight at all the rod ends.  This aft idler is where the slop is.  The idler rocks laterally a good 3/16", however all the play is not transmitted to the rudder itself.  Last annual I wanted to take it apart to see what I could shim up.  I had my hands twisted up there, bent wrenches with a torch to make something grab the flats on the hardware, and then I got smart.  I  realized I had no way to rethread the nut, let alone pull the -40 bolt out the other-side thru the skin.  How does one change the bushing?  I was thinking of cutting a 1/2" hole in the skin to pull the bolt and allow access to the nut.  Then placing a rubber plug, or a stainless wilkie button in the hole.  Anyone ever remove this idler before? Item # 27 in the picture.

 

It also appears that Mooney switched to needle bearings on the later models… I have a K idler I grabbed off of ebay thinking it would fit, the throw was not the same. It had the bearings. If anyone has had one apart recently I'd like to know if the 65's had the needle bearings.

 

Thanks Again,

-Matt

 

 

 

 

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.  How does one change the bushing?  I was thinking of cutting a 1/2" hole in the skin to pull the bolt and allow access to the nut.  Then placing a rubber plug, or a stainless wilkie button in the hole.  Anyone ever remove this idler before? Item # 27 in the picture.

 

-Matt

 

 

 While I cant answer the question of how to, might I suggest you really reconsider poking a hole in the skin? I know I would reject the plane as a purchase candidate if I saw a stainless wilkie button in the skin somewhere and not a proper patch and documentation of why the patch was there. All that said, speak to a pro who has done it before like Clarence or DMax and decide if you even want to tackle this after weighing everything.

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Thanks Mike, that's why I stopped last year. I'll see what I can find. The idlers are really buried back there. I wouldn't be suprisrd if they were installed at the factory before the aft skin went on.

Cheers,

-Matt

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I changed that arm in my B model to get the extra travel , there is a hole , it was a bitch to get the wrenches into the tail , and I used a bent nose needle nose to walk the bolt out and into the elevator , that bolt is about 4 inches long .....

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So I'm debating changing the bushing in the aft most rudder idler in the tail cone.  The play in the system is otherwise tight at all the rod ends.  This aft idler is where the slop is.  The idler rocks laterally a good 3/16", however all the play is not transmitted to the rudder itself.  Last annual I wanted to take it apart to see what I could shim up.  I had my hands twisted up there, bent wrenches with a torch to make something grab the flats on the hardware, and then I got smart.  I  realized I had no way to rethread the nut, let alone pull the -40 bolt out the other-side thru the skin.  How does one change the bushing?  I was thinking of cutting a 1/2" hole in the skin to pull the bolt and allow access to the nut.  Then placing a rubber plug, or a stainless wilkie button in the hole.  Anyone ever remove this idler before? Item # 27 in the picture.

 

It also appears that Mooney switched to needle bearings on the later models… I have a K idler I grabbed off of ebay thinking it would fit, the throw was not the same. It had the bearings. If anyone has had one apart recently I'd like to know if the 65's had the needle bearings.

 

Thanks Again,

-Matt

Matt, I've done this job before, it is a real challenge but can be done. The one we changed had the bolt seized into the bushing. Once we got the nut off we were able to pull the bolt back far enough to cut the head off the spread the rudder and elevator links wide enough to cut the bolt in half, then everything was able to be removed.

The two walking beams had Torrington B-47 needle bearings pressed into each end, once those were replaced and new bushings were installed we were able to slip a new bolt in from a lightening hole in the rib. Getting the washers and nut back on and tight was a challenge but it is possible.

An abundance of patience is required.

Clarence

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Matt, I've done this job before, it is a real challenge but can be done. The one we changed had the bolt seized into the bushing. Once we got the nut off we were able to pull the bolt back far enough to cut the head off the spread the rudder and elevator links wide enough to cut the bolt in half, then everything was able to be removed.

The two walking beams had Torrington B-47 needle bearings pressed into each end, once those were replaced and new bushings were installed we were able to slip a new bolt in from a lightening hole in the rib. Getting the washers and nut back on and tight was a challenge but it is possible.

An abundance of patience is required.

Clarence

Any special Canadian words needed to augment the typical yank A$P vocabulary, Clarence? 

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So a lightning hole in the but rib of the elevator!!! Haha! Got it!

I have 4 nice B-47 bearings and 2 bushings that came out of the M20K idlers I have. They are in good shape! Hopefully, My idler is not too far gone.

Thanks Clarence!!

Also, Canadian question for you... Do you know any Techs that worked at Cold Lake in the 419TS in the NDT back shop? I need some Canidian NDT manuals for another project.

Cheers!!

-Matt

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Matt,

I have a 65 E in the shop at the moment, I'll take a look at it tomorrow to see if it's the same.

Don't know any airforce guys, I signed up in the early eight's, by the time they had an opening I was established in this career and never went in.

Clarence

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Matt,

I have a 65 E in the shop at the moment, I'll take a look at it tomorrow to see if it's the same.

......

Clarence

 

Mine

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So I'm debating changing the bushing in the aft most rudder idler in the tail cone.  The play in the system is otherwise tight at all the rod ends.  This aft idler is where the slop is.  The idler rocks laterally a good 3/16", however all the play is not transmitted to the rudder itself.  Last annual I wanted to take it apart to see what I could shim up.  I had my hands twisted up there, bent wrenches with a torch to make something grab the flats on the hardware, and then I got smart.  I  realized I had no way to rethread the nut, let alone pull the -40 bolt out the other-side thru the skin.  How does one change the bushing?  I was thinking of cutting a 1/2" hole in the skin to pull the bolt and allow access to the nut.  Then placing a rubber plug, or a stainless wilkie button in the hole.  Anyone ever remove this idler before? Item # 27 in the picture.

 

It also appears that Mooney switched to needle bearings on the later models… I have a K idler I grabbed off of ebay thinking it would fit, the throw was not the same. It had the bearings. If anyone has had one apart recently I'd like to know if the 65's had the needle bearings.

 

Thanks Again,

-Matt

Man, I love Mooneyspace for this. I've been trying to track down the last bit of sloppiness in my rudder and lo and behold, this is it. Now on my list for next year's annual.

Matt, I've done this job before, it is a real challenge but can be done. The one we changed had the bolt seized into the bushing. Once we got the nut off we were able to pull the bolt back far enough to cut the head off the spread the rudder and elevator links wide enough to cut the bolt in half, then everything was able to be removed.

The two walking beams had Torrington B-47 needle bearings pressed into each end, once those were replaced and new bushings were installed we were able to slip a new bolt in from a lightening hole in the rib. Getting the washers and nut back on and tight was a challenge but it is possible.

An abundance of patience is required.

Clarence

And now I know this trick to do it with less than normal colorful language.

Thanks, all!

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Just wanted to resurrect this thread for a follow up as I replaced these parts during my last Annual.

Over the past few years I've been tracking down the last bit of play in my rudder/nose wheel steering.  This bushing and needle bearing inserts gave the most payoff for the least amount of time and money in eliminating sloppiness when you wiggle the rudder back and forth.  2 needle bearings and a new bushing was about $10 from LASAR.

This was in addition to replacing 2 heim bearings and having LASAR overhaul the nose steering truss, as well as oversized LASAR bushings at the nose gear retract points.

There is a link in the original post that shows where and what I'm talking about.

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Dumb question, how do you test for rudder play and what constitute as out of tolerance?

And would you be able to point out on the diagram the "numbers" of the parts you are referring to, Andy?

Thanks! 

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The part in question is in the tail section.  The problem is tha Mooney never sealed the hole in the upper horizontal stabilizer skin where the vertical fin spar passes through.  This allows water to drip right on to the walking beam for the rudder and elevator which share the same location and axle bolt.

It's item 61 in the top right corner.

Clarence

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Andy- want to do mine? I gave up. Lol. More important things to work on.  I think the -47 bearings from the K idlers would fit if I got it apart.  

I didn't see the hole in the skin from the factory to pull the bolt out. I might borscope the stab ribs and see what's there. 

Thanks,

-Matt

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7 hours ago, Tommy said:

Dumb question, how do you test for rudder play and what constitute as out of tolerance?

And would you be able to point out on the diagram the "numbers" of the parts you are referring to, Andy?

Thanks! 

The test for rudder play is to stand at the back with the nose wheel straight and wiggle the rudder left and right.  You will feel when the linkage begins to exert resistance on the rudder.  The allowable play is when your inspector (me, in this case) says, "hmm, that seems a little loose."  There is probably something definite written somewhere that Clarence can dig up, but often it is up to the comfort level of the maintenance technician.

On the diagram from the link in the original post, it is #27, and the bolt that everyone hates is #28.  Clarence's reference page is from a different year/serial number, so that's why his says #61.  Its the same part.

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2 hours ago, MB65E said:

Andy- want to do mine? I gave up. Lol. More important things to work on.  I think the -47 bearings from the K idlers would fit if I got it apart.  

I didn't see the hole in the skin from the factory to pull the bolt out. I might borscope the stab ribs and see what's there. 

Thanks,

-Matt

The hole is in the left inboard rib that allows the bolt to be pushed into the horizontal stab.  It is barely visible until you pull off the tail cone  and remove the elevator bungees and linkages.  Then, when you start sliding the bolt out, you'll say, "oh that's what that hole is for!"

I allotted myself a half day to do the job, it actually took about 2 hours of work not including head scratching and water breaks.  Most of that was disassembly and removal of the elevator bungees and linkages and keeping everything labeled and sorted.

At least we have a tail cone that comes off.  I think for airplanes with the full length rudder you might have to remove the rudder itself.

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I've never been able to find a spec for free play in the manual, so as Andy says its up to the maintainer to come up with a limit.  I will wiggle the rudder and start looking for the worn parts and then decide the course of action.

Mooney with its many rod bearings and linkages can have a small bit of wear in many spots which leads to larger movement at the flight control.

Clarence

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Sloppy controls and risk of flutter. I'm not too sure how much a vertical surface is effected by flutter, vs a lifting surface. 

To me, probably more sensitive due to the fact it's loading is similar in cruise both right and left sides. I don't want to find out and prefer tighter controls if I'm able to improve them.

-Matt

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There is no risk of flutter as long as the control surface is balanced.

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Because the tail always makes down force, the trim jack screw is always in compression in flight. So the play in the jack screw doesn't matter when flying. The elevator always has a balance between the aerodynamic force on it and either the spring bungees or the bob weight. Any slop in the controls forward of that will just manifest itself in a dead band in the control response.

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10 hours ago, Tommy said:

What is the potential danger of having a lot of play?

Poor spin recovery, requiring a parachute, which means you're a Cirrus pilot!!

Clarence

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2 hours ago, M20Doc said:

Poor spin recovery, requiring a parachute, which means you're a Cirrus pilot!!

Clarence

Now I can see why some people think chute will encourage maintenance corner-cutting...

Tempting :D 

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