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Johnson bar hard to secure into lower socket


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Hi guys. This may sound funny, but i'm having a little trouble with my johnson bar when retracting the gear. I'm having trouble 

getting it to go into the lower socket, it's not easy. Can this be an indication of the gear being out of adjustment or something else. 

I do try to twist the handle while stowing in the socket, but I don't think it should be the difficult. 

Thanks for the help 

Ron 

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8 minutes ago, M20D6607U said:

Hi guys. This may sound funny, but i'm having a little trouble with my johnson bar when retracting the gear. I'm having trouble 

getting it to go into the lower socket, it's not easy. Can this be an indication of the gear being out of adjustment or something else. 

I do try to twist the handle while stowing in the socket, but I don't think it should be the difficult. 

Thanks for the help 

Ron 

Twisting the handle is not necessary or beneficial in any way that I can imagine. Is this a new problem with the plane or is this a new plane for you?

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Also check whether a shift in your carpet near the boot that might be binding the movement. I had this problem after I changed the center carpet.  If it’s not something obvious,  it’s probably worth the shop putting on jacks to check out the whole system.

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New carpet, or anything under the carpet, or on top of the carpet...  biggest challenge for the ‘up’ lock block on the floor...

See if you have any wires for headsets and things like that getting crushed there...

See if the carpet is showing compression signs near the base of the J-bar...

PP thoughts only,

-a-

 

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Does the handle slide freely down when you unlock to go gear up? Can you make it slide on the spring real easy between the up and down locks? As mentioned above, anything blocking the handle going down to the floor? Is the mouse boot bunching up by being pushed down into the hole around the lower part of the gear handle? Just a few things to look at next time in the air or on jacks. 

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I had a lot of difficulty getting mine into the uplock socket when the little knot on my boot retaining rope was facing down towards the floor ( I ended up cutting the rope off and discarding it)...it’s amazing how little clearance there actually is between the bar and the floor! A simple carpet shift or the boot folding on itself is all that it takes to foul it up.

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Doesn't sound funny. A client recently bought a C with the opposite issue. Getting it into the retracted lock is no problem, but getting it out of the extended lock took two hands. 

Solution (hopefully) is the same as others mentioned - lubrication. Being done with a few other tweaks. We'll see...

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First, make certain that the bar and its holder are well lubricated.  I had trouble seating the bar in its panel holder and lubrication solved the issue.

The other thing to check is the Johnson bar boot.  It is secure, or is it riding up the bar?  it can get in the way as well.

Edited by steingar
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If it is at all possible, diagnosis this while the plane is sitting on jacks on the ground. Futzing with the gear while taking off is a less than desirable time to do diagnostic work, and trying it after getting up to altitude just makes it worse.

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When I rebuilt my plane, I had a real problem getting the gear up.  It required two hands.  Two MSC's claimed it was because the parts were new and rebuilt.  We first tried to put plastic bushings on the retraction rods to compress the main springs more.  The gear worked much better.  Then we went to the factory and perused the original drawings and found that there were three different length retraction rods during that era (even tough there were only two different body lengths at the time).   We found a pair of the longest retraction rods, bought new springs and now the gear goes up with two fingers.   My guess is there is a problem with insufficient assist spring tension or a heim bearing is binding or something is bent or out of alignment.

John Breda

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On 3/25/2019 at 5:26 PM, Igor_U said:

Did you inspect the socket for obvious damage and wear? Maybe take a picture and post it here?

I know LASAR is selling down-lock socket but I'm not sure if they have upgraded up-lock one.

Thank-you for the recommendation. I will inspect the socket and then I'm going to put the plane on jacks and swing the gear

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3 hours ago, M20F-1968 said:

When I rebuilt my plane, I had a real problem getting the gear up.  It required two hands.  Two MSC's claimed it was because the parts were new and rebuilt.  We first tried to put plastic bushings on the retraction rods to compress the main springs more.  The gear worked much better.  Then we went to the factory and perused the original drawings and found that there were three different length retraction rods during that era (even tough there were only two different body lengths at the time).   We found a pair of the longest retraction rods, bought new springs and now the gear goes up with two fingers.   My guess is there is a problem with insufficient assist spring tension or a heim bearing is binding or something is bent or out of alignment.

John Breda

Thank-you John! I will check that. 

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1 hour ago, SheryLoewen said:

Sounds like the gear doors a rigged to tight.

Paul

Hi Paul! You know this plane well. Rudy Gonsalves N6607U. The gear doors are rigged perfectly. I called up and left a message for Robert the other day and am waiting for a call back. I would like to take it up to your place (Lasar) and have the experts check it out. I did not know the sockets should be lubed. I can jack it up and swing the gear. 

Ron 

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On 3/25/2019 at 5:43 PM, M20D6607U said:

Hi guys. This may sound funny, but i'm having a little trouble with my johnson bar when retracting the gear. I'm having trouble 

getting it to go into the lower socket, it's not easy. Can this be an indication of the gear being out of adjustment or something else. 

I do try to twist the handle while stowing in the socket, but I don't think it should be the difficult. 

Thanks for the help 

Ron 

I had the same problem with my ‘65C when I first acquired it. I sprayed some lubricant onto the handle of the Johnson bar and it hasn’t given me any more problems.

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 Can someone point me to the section in the maintenance manual that covers Johnson bar lubrication? What is the approved lubricant in this application? Our airframe has ~3600 hours on it and has been in the family for 3500 of them. There is not nor to my knowledge has there ever been lubricant on the Johnson bar or socket.  The only folks I’ve seen mention this are @steingar and @midlifeflyer. This begs the question, if these birds are requiring lubricant where many others are not (and never have in my case), is there another problem being masked ?

Edited by Shadrach
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Sorry, this is one I left up to my mechanics.  I had the panel holder replaced (old one got pranged in my little incident).  The new one got stiff.  Based on advice from the board I sprayed it with Tri Flow.  That solved the problem for awhile, but when it came back it did so with a vengeance, the holder got so sticky that I thought I was going to have to gear up my aircraft.  That's when I involved my mechanics, who lubed the system up so nicely that the bar now springs of its own volition into both of its holders.

But sorry, I don't know what they used, though they told me they disassembled everything.

Edited by steingar
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I recently started having a problem securing the gear in my 67 F (Johnson Bar) after dozens of successful gear operations.  I thought it could be any number of issues and was concerned about the gear retract issues on take off.  Turns out that I was waiting just a second or two too long in raising the gear and the airspeed was an issue in getting the gear secured.  Once I raised the gear earlier after rotation I have not had any issues since.  Try flying and raising the gear closer to rotation speed and that might solve the issue.

Good luck and keep us posted. 

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There is a sweet spot where the gear should move relatively easy. Airspeed, Mooney dip, technique, rigging, hardware etc all play a part. If your gear is difficult to move and/or latch it most likely needs attention. It's a simple system but it takes someone who understands it

Sent from my SM-T350 using Tapatalk

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14 hours ago, Shadrach said:

 Can someone point me to the section in the maintenance manual that covers Johnson bar lubrication? What is the approved lubricant in this application? Our airframe has ~3600 hours on it and has been in the family for 3500 of them. There is not nor to my knowledge has there ever been lubricant on the Johnson bar or socket.  The only folks I’ve seen mention this are @steingar and @midlifeflyer. This begs the question, if these birds are requiring lubricant where many others are not (and never have in my case), is there another problem being masked ?

I've mentioned it a few times.  I use silicone spray on the slider (the same stuff you spray on brake calipers slider pins and the starter throw-out gear shaft).  Works great.

I've never seen a specific reference in the Service Manual for the Johnson Bar slider lubrication, all that's really called for on the landing gear is the standard low temperature oil lube (TriFlow or LPS-2).

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