Johnson Bar retainer

[Raymond Ritter]

The Johnson bar on my '62 M20C takes two hands to raise and lower the gear. the problem is with the block and release button. I can't do it smoothly with one hand but it takes a monumental effort with two hands to raise the gear. Needless to say having my hands off the yoke on departure is not ideal! Efforts to lower the gear are equally difficult. Just had it up on chocks, the gear tension is in spec. All agree it is the receiving block mounted under the panel (recently replaced with a new Lasar unit). The floor retainer is functioning fine. I have 500 hours in a '61 M20B and never had problems putting the gear up or down with one hand.  It's grounded unless I want to fly it gear down.

[Jim Peace]

This happened to me.  I have a 64 C that had flawless gear tensions.  Sent it in for annual at the local MSC and it took two hands to get the gear down.  I almost thought I was going to have to land gear up.  The issues was not the block although that was new.  The issue was during the lowering process.  MSC said it was done by the book.  Of course there was something wrong.

I took it to a friend who never even worked on a mooney.  I asked him to call LASAR and get instructions.  I am a good LASAR customer so they spent 15 min with him on the phone for free.  He adjusted some stuff under the belly and it has worked perfect ever since......

[carusoam]

If everything is perfect…

1) Check the carpet… a few MMs of extra carpet in the wrong place can be problematic…

2) installing the block incorrectly is really hard to do… but that doesn’t mean it can’t be done…

3) Try to explain what is difficult about it…. The button push, the sliding mechanism, or moving the bar….

4) was it the same while up on jacks?

5) Was it only the lock block that was changed?

6) lots of pics of the block installed may be helpful…

7) After that… see Jim’s post above… who did  the gear adjustment, from what manual…

8) The only thing left… any chance the J-bar got bent?  Uncontrolled swings through the cabin can do that…

 

My 65C was difficult to lock the bar down… the carpet fibers were a bit too tall near the hinge point…

Best regards,

-a-

[chriscalandro]

Make sure there’s nothing getting it caught up on the floor. In front of the Johnson bar. 

[RLCarter]

Get an A&P with the rigging tools and the latest Service Bulletin (instructions & SPECs) and adjust your gear… as mentioned above verify the bar isn’t pinching the carpet at floor/wheel well area…

[Skates97]

37 minutes ago, carusoam said:

If everything is perfect…

1) Check the carpet… a few MMs of extra carpet in the wrong place can be problematic…

3) Try to explain what is difficult about it…. The button push, the sliding mechanism, or moving the bar….

My 65C was difficult to lock the bar down… the carpet fibers were a bit too tall near the hinge point…

Best regards,

-a-

I had problems like two of the ones you mentioned. 

1) I had this exact problem when I replaced the block. They get sort of egg shaped when they wear which means the bar doesn't go quite as far. Somewhere along the way someone covered the wheel well with carpet, which was great until the new block was installed and the bar needed to go all the way forward. I trimmed the carpet there and problem solved. I also put bright yellow duct tape where I removed the carpet which stands out while the gear is retracted. 

3) A different time it was getting harder and harder to slide up and lock into place. I removed the button and pin, cleaned them and the hole it slides in well, lubed and reassembled, and was amazed at how easy it was to slide up in afterwards. 

[carusoam]

Great details Richard!

Thanks for sharing them!

Best regards,

-a-

[chriscalandro]

As an alternative test I have a black anodized set of up and down blocks I can sell you. It comes with a the documentation you need for you and your mechanic to go over and compare against what you have to meet the requirements of an owner produced part. 
 

it’s possible the one you have was not manufactured properly. 

Edited February 9, 2023 by chriscalandro

[BDPetersen]

Check gear rigging tensions and downlock block for wear. Had same issues.

[cliffy]

Lets determine exactly where the issue is-

Can you push the unlock button easily with your thumb to raise the gear? How about when the bar is not in the block?

If so-  can you slide the top of the handle down easily to disengage it from the block?

Do you have to push real hard fwd on the Johnson bar to get the top to slide down to disengage?

Does the slide work easily or is it hard to slide when not engaged in the upper block?

With the change of the block on the panel it (being a tighter circular hole now and not elongated toward the aft)

may require more forward movement of the top of the Johnson bar to get engagement with the block. than what you have been used to. 

As mentioned above check the carpet on the aft side of the nose wheel well to see if that is keeping the gear bar from moving foreword enough without excessive force.

Also check the hole at the bottom of the Johnson bar to see if the material in the hole is now bunching up and blocking the movement.

Also check the weld at the bottom on the Johnson bar to see if it might be cracked and not allowing the bar to go forward enough to engage the block  THIS HAS HAPPENED!

There might be a couple of other things to check but lets get through these first. 

DO NOT DO ANYTHING WITH THE JOHNSON BAR UNLESS THE AIRPLANE IS ON STABLE JACKS!

DON'T MESS AROUND WITH IT IN FLIGHT!

Edited February 9, 2023 by cliffy
add

[N201MKTurbo]

It is probably rigged wrong. I can guarantee that you can have it in spec according to the preload tools and be totally wrong.

A properly rigged Johnson Bar system takes very little effort to operate. 

The Johnson bar nose wheel adjustment is kind of tricky. There are many more ways to get it wrong than right. And it will still pass the rigging tool test.

I would suggest removing the links to the main gear so you can just work the nose. 

Start by disassembling both eccentrics and cleaning the years of crud from them so they can actually be finely adjusted. 

Then with one nose rod installed, adjust the eccentric to a preload near the bottom of the range. Then remove that rod and hook up the other one and adjust it as close as you can to the same preload as the first one. Then hook up both and check the preload.  If it is in range move on to checking the preloads with the mains hooked up.

The mains are easier because they have springs. If you observe the springs in the retract rods while the gear is swung, you want then to be just shorter than the springs completely compressed as the overcenter link goes through center. If you do this, the mains will be within the preload range unless something is broken.

After you do all this, recheck all the preloads if they are in range you are done. If the nose wheel is out of range (it shouldn't be) start from the beginning and adjust your single rod preload accordingly.

[Guest]

What about if the Johnson bar is bent? The gear tensions can be correct but tha handle still be difficult to engage or disengage.  Plain old lack of cleaning and lubrication comes to mind.

[N201MKTurbo]

5 minutes ago, M20Doc said:

What about if the Johnson bar is bent? The gear tensions can be correct but tha handle still be difficult to engage or disengage.  Plain old lack of cleaning and lubrication comes to mind.

How can it possibly be lubrication? it is required to be lubed every 100 hours? 

[cliffy]

6 minutes ago, M20Doc said:

What about if the Johnson bar is bent? The gear tensions can be correct but tha handle still be difficult to engage or disengage.  Plain old lack of cleaning and lubrication comes to mind.

Yes like I noted a few other things can be wrong but we need a starting point.

[Guest]

1 minute ago, cliffy said:

Yes like I noted a few other things can be wrong but we need a starting point.

I think we’re all in agreement.  I’d start with jacks, but that would be a whole new controversy.

[Sabremech]

15 minutes ago, M20Doc said:

What about if the Johnson bar is bent? The gear tensions can be correct but tha handle still be difficult to engage or disengage.  Plain old lack of cleaning and lubrication comes to mind.

You beat me to it! Been there on the one I use to own. 

Edited February 9, 2023 by Sabremech

[N201MKTurbo]

I've never seen a bent Johnson bar or a broken weld on a Johnson bar. I'm not saying they don't exist, but how did they get that way? Other than a gear up, I would imagine that they started with someone "adjusting" the rigging.

[0TreeLemur]

21 minutes ago, N201MKTurbo said:

I've never seen a bent Johnson bar or a broken weld on a Johnson bar. I'm not saying they don't exist, but how did they get that way? Other than a gear up, I would imagine that they started with someone "adjusting" the rigging.

They are pretty darn strong.  Early in my Mooney experience while going missed on a practice approach I tried to raise the gear while going 90+ knots.  I pushed on that bar as hard as I could- to no effect.  Then my instructor told me to pull back to slow a bit then unload the wing, and the gear came up easily.

[Fly Boomer]

11 hours ago, Raymond Ritter said:

The Johnson bar on my '62 M20C takes two hands to raise and lower the gear. the problem is with the block and release button. I can't do it smoothly with one hand but it takes a monumental effort with two hands to raise the gear. Needless to say having my hands off the yoke on departure is not ideal! Efforts to lower the gear are equally difficult. Just had it up on chocks, the gear tension is in spec. All agree it is the receiving block mounted under the panel (recently replaced with a new Lasar unit). The floor retainer is functioning fine. I have 500 hours in a '61 M20B and never had problems putting the gear up or down with one hand.  It's grounded unless I want to fly it gear down.

Raymond,

I'm not a J-bar gear guy, but your description of the problem has elicited quite a range of suggestions.  I think you will get closer to isolating the problem if you follow the diagnostic procedure from @cliffy above.  Your answers to those questions may generate new questions, but you will be closer to a resolution.  Keep working the problem until you figure it out.

[N201MKTurbo]

1 hour ago, 0TreeLemur said:

They are pretty darn strong.  Early in my Mooney experience while going missed on a practice approach I tried to raise the gear while going 90+ knots.  I pushed on that bar as hard as I could- to no effect.  Then my instructor told me to pull back to slow a bit then unload the wing, and the gear came up easily.

When I owned a J Bar Mooney, I found if you kick a little rudder it will come up easier if you are going too fast.

[Fly Boomer]

2 minutes ago, N201MKTurbo said:

When I owned a J Bar Mooney, I found if you kick a little rudder it will come up easier if you are going too fast.

Before I bought my airplane, I thought I wanted an E or an F.  Flew two different M20Es about 10 hours each, and never was able to get the almost effortless retraction that some report.  Didn't seem to matter what my speed was or my technique.  Since I had trouble with two different airplanes, it was probably operator error.

[Culver LFA]

1 hour ago, 0TreeLemur said:

They are pretty darn strong.  Early in my Mooney experience while going missed on a practice approach I tried to raise the gear while going 90+ knots.  I pushed on that bar as hard as I could- to no effect.  Then my instructor told me to pull back to slow a bit then unload the wing, and the gear came up easily.

Just imagine all the stress the electric gear Mooneys are experiencing in those instances. Those pilots have no physical gauge of how their climb/speed is putting the gear components under so much pressure because the switch on the panel feels the same either way

On a serious note, if going missed in cruddy weather/IMC, you could always consider leaving the gear down and climb out until there is more more distance between you and the ground.  You can do the 'push' to assist the gear swing but honestly there is plenty of time to swing the gear on the way to the hold and these airplanes climb really well with the gear still hanging out.

[Sabremech]

2 hours ago, N201MKTurbo said:

I've never seen a bent Johnson bar or a broken weld on a Johnson bar. I'm not saying they don't exist, but how did they get that way? Other than a gear up, I would imagine that they started with someone "adjusting" the rigging.

The Johnson bar is bent by someone accidentally kicking the handle out of the uplock in flight and it slamming forward into the instrument panel and down lock. This isn’t a new issue but something few people think about. 

[phxcobraz]

The gear speed is 120mph but I find about anything over 100mph needs a bit of right knee to get the bar back into the geardown lockblock. Gear up is just a matter of getting it done before going too fast. As others stated carpet and/or Jbar boot can get bunched up and give some grief.

[carusoam]

21 hours ago, Fly Boomer said:

Before I bought my airplane, I thought I wanted an E or an F.  Flew two different M20Es about 10 hours each, and never was able to get the almost effortless retraction that some report.  Didn't seem to matter what my speed was or my technique.  Since I had trouble with two different airplanes, it was probably operator error.

Speed is important…

Very easy while going slowly…

By the time we reach the altitude where many want to raise the gear…

We can potentially be going too fast to make this easy…

 

there is a small driving force to lift the gear as soon as practical…

The opposite is also true… there is another speed that makes putting the gear down easy…

Experiment with small steps in speed…  the force on the J bar increases dramatically with speed…

PP thoughts only… not a CFI…

Best regards,

-a-