Johnson bar issues

[Tim Loftus]

Hello all,
I was recently flying by 1968M 20 C and had a terrible time locking my landing gear in place. When we finally got the landing gear up, we continued to our destination and then had a stressful and difficult time Locking the gear down. There are no obvious problems with the Johnson bar, but something is clearly wrong. The difficulty seem to be getting the bar to lock in place both when raising the gear and lowering the gear. Moving the bar backwards and forwards was normal. Does anyone have any comments or ideas?

Thanks!

Tim L

[Jim Peace]

I had a MSC give me this exact problem. It took an older school mechanic to call LASAR and spend about 15 minutes with them on the phone to diagnose and fix. Had something to do with “pre sets” on some sort of tension component. Shows you what I know, I just write checks. 
 

Just a few turns of some tension adjustments in the belly and it was fixed. The MSC had no clue what they were doing nor did they swing the gear after messing with them during the annual.  Mine was so bad I had to use both hands and really muscle the bar to get it down and I was very concerned about it staying down if I hit a bump. 

[Matthew P]

1 hour ago, Jim Peace said:

I had a MSC give me this exact problem. It took an older school mechanic to call LASAR and spend about 15 minutes with them on the phone to diagnose and fix. Had something to do with “pre sets” on some sort of tension component. Shows you what I know, I just write checks. 
 

Just a few turns of some tension adjustments in the belly and it was fixed. The MSC had no clue what they were doing nor did they swing the gear after messing with them during the annual.  Mine was so bad I had to use both hands and really muscle the bar to get it down and I was very concerned about it staying down if I hit a bump. 

Sounds like your MSC is on OTA (On their azz) as they missed an AD or two. Might be time to find a reputable shop.

[Jim Peace]

13 minutes ago, Matthew P said:

Sounds like your MSC is on OTA (On their azz) as they missed an AD or two. Might be time to find a reputable shop.

That was years ago....as of now they are still banned form working on my plane....

[bonal]

Last couple of flights I had a hard time getting it to lock into the lock down block.  Believe me I really tugged on it on short final green light was on and no issues.  Next flight I brought some spray lubricant and shot it under the slider and into the block. Next gear cycle it went into the block and locked with zero effort.  Try the simplest solution first.

 

[Hradec]

Having gone through my entire gear several months ago myself.  There is a lot going on in the landing gear system and lots of clearances to balance. read the manual look at the parts diagram. get a set of Jacks and the mooney tools and torque wrench to measure the downlock break over.  I believe the manual has you disconnect some rods and has you check for binding in each of the gear. this is a good time to lube because you can move each gear by hand. find all the grease fittings. lube all the rod ends. make sure nothing is excessively worn. you should do all this before making any adjustments. 

check the adjustment with break over tools and torque wrench. when you start making adjustments everything changes ( torque, how far gear retracts and door closing) The gear is ingenious and once you understand it it is beautiful  in its simplicity. If there is excessive effort, something is wrong. the tubes are thin they might have some corrosion. you are asking for trouble if you have to muscle the gear. I found that maintaining momentum of the gear handle and the proper airspeed for gear operation also helps a lot. A correctly lubed and adjusted gear should give years of trouble free ops once you sort it out correctly

 

[MikeOH]

If this was a sudden change WITHOUT just coming out of maintenance, look for something jamming the mechanism.  The one time this happened to me (with a rental M20B) was when a plastic pen had become stuck in the floor opening (yeah, the boot was trashed).

[47U]

5 hours ago, Tim Loftus said:

The difficulty seem to be getting the bar to lock in place both when raising the gear and lowering the gear.

Is the problem with sliding mechanism of the handle into the block?  Or is the problem with the throw of the bar that you cannot get it far enough to try to engage the sliding handle into the block?

That might be unusual to have issues on both the up-lock and down-lock functions.   @Hradec is correct, it’s not overly complicated, but does require understanding of how the system operates to get it dialed in.  An adjustment on one gear will affect the adjustment of the other two.  Best practice is to use a dial indicator torque wrench when checking/adjusting preloads (in my opinion).  You also might want to check for bent tubes.

[Hradec]

The entire system needs to be checked also an worn out up and down lock that the top of the handle locks into. Make sure its not worn out. What I was trying to express with my post, check the whole system don't put on a bandaid that masks other problems

[201Steve]

Heresy. J bars never have issues. 
-Anyone on the internet with a J bar

[Skates97]

8 hours ago, Matthew P said:

Sounds like your MSC is on OTA (On their azz) as they missed an AD or two. Might be time to find a reputable shop.

Agree, pre-loads are supposed to be checked every annual. 

7 hours ago, bonal said:

Last couple of flights I had a hard time getting it to lock into the lock down block.  Believe me I really tugged on it on short final green light was on and no issues.  Next flight I brought some spray lubricant and shot it under the slider and into the block. Next gear cycle it went into the block and locked with zero effort.  Try the simplest solution first.

 

I had a similar issue once early on with my plane. Jacked the plane up, released the gear, took out the thumb button which was all gunked up and cleaned, lubed, and replaced along with the shaft where the handle slides up and down. Made a big difference.

I agree with the others that if it suddenly became difficult without any maintenance performed I would look for something jamming the mechanism.

[Jim Peace]

3 hours ago, Skates97 said:

pre-loads are supposed to be checked every annual. 

That’s funny right there….

remember almost everyone who knows how to work on these planes is either retired or beyond…..

[Hradec]

5 hours ago, Jim Peace said:

That’s funny right there….

remember almost everyone who knows how to work on these planes is either retired or beyond…..

I learned a lot in my 6 yr project. Im an A&P IA. Not retired and I don't think I'm dead yet.  After rigging my flight controls with travel boards. I decided to help rig a plane that had been through 2 owners and at least a decade of annuals, flew slow and needed a heavy foot on the rudder at cruise. Logbook showed many adjustments.

Apparently I'm the only one that jacked the plane, leveled it and used the travelboards. Obviously this had nrver been done before. Ailerons were horribly off.  Plane gained 6 knots and flew straighter. Be careful who you trust to work on your plane. The only thing that makes some one po professional is they charge you for the mess they cause.. same goes for landing gear. It takes time, knowledge, tools and patience to do it right. After my 6 yr wing off project, only needed to adjust the prop governor after the test flight. 

[Z W]

Just a thought since you said you were new to flying this plane - make sure you are raising the gear at slow speeds. It should come up at 80 MPH KIAS. It gets significantly harder to raise and lock it if you accelerate past that due to aerodynamic forces on the gear.

[bonal]

On 7/21/2025 at 1:17 PM, Hradec said:

The entire system needs to be checked also an worn out up and down lock that the top of the handle locks into. Make sure its not worn out. What I was trying to express with my post, check the whole system don't put on a bandaid that masks other problems

I don’t know if this was in reference to my comment about spraying lubricant on the bar slider and lock blocks.  I agree that there are many moving parts that could cause a problem and hopefully they are being checked during every annual.  Having said if I lubricated the bar and it continues to be difficult to lock I would consider other issues.  As it was the problem went away after applying triflow under the slider and on the blocks so since nothing else was touched I think it is safe to say that’s where the problem was.  
just saying 

[Gary0747]

I have been having a similar issue with my Johnson bar release button   It seems harder to release as easily when compared to the 34 years I have owned and flown this plane.  I have participated in nearly every annual in the past and the preloads have remained constant and never needed adjustment.  The lock down block was replaced around 10 years ago and everything is well lubricated.  With the bar out of the socket I can feel the tip of the release pin point that engages the Johnson bar.   There is some slight burring or deformity of the point that engages the top of the Johnson bar.   This may be entirely normal and the problem be elsewhere    Has anybody noticed and dealt with anything similar?

[LardLad]

Probably not your problem, but I had a similar issue once that turned out to be my beat up carpet getting tangled up around the base of the johnson bar.  This was remedied by a new checklist item to take a close look at the floor before takeoff for carpets, water bottles, ipads, or anything else you're about to smash into the mechanism.

In any case, if you have a rough time getting the gear up I'd suggest trying to get it back down and come back to the airport to have a look.  I didn't in the flight I'm talking about above, I just said "why is this so dang hard today" and forced them up.  Seems like a pretty dumb thing to do after you think about it for a minute though, just too focused on performing the flow check and staying out of the terrain I guess.