landing gear locked in down postion

[btbunch]

I have flown my 1965 M-20-C, 5798Q, for 20 years. Yesterday, The johnson bar locked in the gear down position and won't budge. The release button moves, but the sleeve will not slide down. I tried everything I couls , but no-go. What has broken in the release mechanism/ I know I'm lucky to have locked gear down, but...

[gsxrpilot]

How many times have you lubed the johnson bar in those 20 years? 

 

[btbunch]

i have lubed it every annual. The majority of the annuals were done by a Mooney A&P/IA. who is unfortunately no longer with us. The aircraft has gotten very good maintainance , but is 52 years old. When the release button is depressed the u-shaped pin moves right buy the sleeve will not slide down the bar.

[DXB]

 I know from past experience that sleeve can bind - in my case it was  hard to slide up. If it's too inconvenient to jack it, I'd try spray lubing the heck out of that component on the ground and try one more time at slower speeds while straight and level in the air - perhaps with someone else flying from the right seat to avoid distraction while you try to mobilize the sleeve. I doubt there's much risk you won't be able to get it locked down again if the sleeve does mobilize, but others can weigh in - I've posted stupid ideas here before  - may be safest to just jack it.

[btbunch]

Thanks, DXB, after reading the first reply, I got my spray lube out and started getting ready to go out to the hangar and do just that. If only it is as simple fix as a little grease I would be one happy Mooney  man!

[mooniac15u]

12 minutes ago, DXB said:

 I know from past experience that sleeve can bind - in my case it was  hard to slide up. If it's too inconvenient to jack it, I'd try spray lubing the heck out of that component on the ground and try one more time at slower speeds while straight and level in the air - perhaps with someone else flying from the right seat to avoid distraction while you try to mobilize the sleeve. I doubt there's much risk you won't be able to get it locked down again if the sleeve does mobilize, but others can weigh in - I've posted stupid ideas here before  - may be safest to just jack it.

Messing with it in the air could turn a minor problem into a really bad day.  Sorting out the problem on jacks seems prudent.

[Andy95W]

I had the exact same issue as Dev- difficulty locking the slider up.

I used silicone spray on my and it works fantastic.  Using an oil like LPS-2 or even Tri-Flow likes to pick up dust and just gets gummy over time.

I agree, I would definitely do this up on jacks, with the belly panels off, rather than risk your engine and prop.  (This is a perfect case to ask how you would explain this to an FAA inspector or your insurance agent.)

 

[Bob_Belville]

After 20 years I'm sure you know how the parts fit together and that you've pushed the bar forward and twisted the handle to free it. 

I suspect that you will need to get the plane on jacks so that you can really wrestle with it. The Button that you push can be screwed off. That might allow a little more travel for the pin that fits the groove around the top of the handle. 

The threaded rod that the long spring in on that holds the sleeve up goes through a hole in a "washer" welded inside the main tube. There's a nut on the bottom of the threaded rod.If that has gotten jambed it might help to rap on the tube. For that matter, once you have it on jacks tap on the sleeve. You should be able to tell if it's just stuck or if it's catching on something. 

If you've been lubing the sleeve annually but have not had it apart it would be good to take it apart and clean the accumulated grime. When reassembling be careful that the nut on the threaded rod is run up the correct amount. You want the spring compressed enough to put good pressure on the sleeve but it need to allow full travel.   

[btbunch]

Many thanks to all who have replied. The advice has been informative. My A&P/IA is out of town until next week, so if do fly, I guess I'll be flying it as a M-20-d below 120 mph. This is a great board and I hope I'll be able contribute to it in the future. Again, thanks to all.

[MBDiagMan]

TWIST the handle while pulling down and I bet it will come down.

[Tommy]

I don't know much about the Johnson bar and how it operates. But one thing I do know is never to take off when a critical component of your plane is not functioning as it should. Why take the risk? Put it on the jack and swing it. Your life is worth a lot more than a 3-hour bill from your mechanic. 

"My A&P/IA is out of town until next week, so if do fly, I guess I'll be flying it as a M-20-d below 120 mph" 

The NTSB report will read like a classic "Swiss cheese" story...