Steve Hughes Posted October 21 Report Posted October 21 We're in for our first annual and on our squawk list to check is the Johnson bar doesn't seem to spring up into the down-lock holder completely. We physically have to lift and twist to get it to the point where it engages the gear down light. Our A&P isn't seeing information on how the bar operates or how to disassemble it to check its function. Anybody have any experience on how it works or how to free it up to spring into place like it should?
Flyler Posted Tuesday at 11:37 PM Report Posted Tuesday at 11:37 PM Check the bore hole of the down lock block to make sure it doesn't have a step worn into it. You want to get a good look at it anyways, to make sure it isn't too oval-shaped from wear. There have been some gear collapses due to this. 2
AdamJD Posted Wednesday at 01:11 AM Report Posted Wednesday at 01:11 AM Are you saying the spring that extends the grip and top button isn’t pushing the button up enough to seat firmly in the gear down block? If that’s the case, a new gear down block probably won’t fix that. Maybe @jetdriven knows how to disassemble the handle to inspect the spring. Also, when you say to have to do that to get it to engage the gear down light, is it otherwise firmly in the gear down block? If so, maybe the metal arm that engages the light is bent? It’s unlikely but I’d check it. However, if it’s barely engaging that arm, I’d be concerned about it the gear bar coming out of the block.
takair Posted Wednesday at 01:17 AM Report Posted Wednesday at 01:17 AM As Tyler suggested, the block may have a step. Next time you are flying with gear up, reach a finger in there to feel for it on the near side of the block. You can also cell phone photo it. My guess is that a little extra forward pressure on the bar would get it past the step and it will snap up. The spring in the gear handle does not have significant force to overcome at step or misrigging.
hammdo Posted Wednesday at 01:42 AM Report Posted Wednesday at 01:42 AM Besides the egg shaped block, a bent j-bar can also make it hard to engage. Put a straight edge on it to make sure it is straight… -Don
Jim Peace Posted Wednesday at 04:49 PM Report Posted Wednesday at 04:49 PM 15 hours ago, hammdo said: a bent j-bar There may be a pill or a procedure for that... 5
Immelman Posted Wednesday at 05:11 PM Report Posted Wednesday at 05:11 PM A crafty A&P/IA might be able to take it apart while the airplane is jacked with the gear broken over, and adjust the spring force, perhaps with a new spring, perhaps a washer stack or similar. 1
Steve Hughes Posted Thursday at 06:15 PM Author Report Posted Thursday at 06:15 PM Our A&P found that "lip" and sanded it a bit to smooth it out. I read about gear collapse after landing due to the oval shape. I'll check that issue next flight.
MikeOH Posted Thursday at 07:49 PM Report Posted Thursday at 07:49 PM 1 hour ago, Steve Hughes said: Our A&P found that "lip" and sanded it a bit to smooth it out. I read about gear collapse after landing due to the oval shape. I'll check that issue next flight. Hmm, I hope that doesn't INCREASE the odds of it 'popping out' and causing a gear-up! 1 1
Aviationist Posted Saturday at 01:04 AM Report Posted Saturday at 01:04 AM That ... doesn't sound like a thing you should have done.
Bart Chilcott Posted 19 hours ago Report Posted 19 hours ago (edited) I recently had to replace my J bar on my 65 E. Taking the handle assembly apart isn’t difficult. Your spring may be too compressed overtime and lost its strength or the interior may have become corroded and creating drag that don’t allow the handle to slide as it should. I may have the interior parts (handle, spring etc..) parts from my old one if you find you need any of it. If you’re sanding the inside of the lock block, do yourself a favor and replace it ASAP. Edited 19 hours ago by Bart Chilcott
Steve Hughes Posted 2 hours ago Author Report Posted 2 hours ago 17 hours ago, Bart Chilcott said: I recently had to replace my J bar on my 65 E. Taking the handle assembly apart isn’t difficult. Your spring may be too compressed overtime and lost its strength or the interior may have become corroded and creating drag that don’t allow the handle to slide as it should. I may have the interior parts (handle, spring etc..) parts from my old one if you find you need any of it. If you’re sanding the inside of the lock block, do yourself a favor and replace it ASAP. Thanks, Bart. Yeah, what you describe is kind of what I'm thinking part of our issue might be, in addition to the block. Very doubtful about corrosion given the plane came from San Diego and Arizona before that, but the spring inside the handle could be compressed, so I may want our A&P to have a look. And, yeah replacing that block(s) is a priority; unfortunately Lasar says they don't have any and no restocking in sight. Any other places carry them?
47U Posted 2 hours ago Report Posted 2 hours ago 17 minutes ago, Steve Hughes said: Any other places carry them? A search on controller.com shows a used one for sale at Dawson Aircraft… they’ll probably send you a pic so you can see how worn it is. https://www.controller.com/parts/search?SearchType=Start&PartNumber=560046 One of the salvage yards would likely have a serviceable down lock block.
Skates97 Posted 38 minutes ago Report Posted 38 minutes ago Put the plane on jacks, raise the gear and look up in the down lock to make sure it isn't wallowed out as others have suggested. It is also very easy to take the button off and remove the spring and locking mechanism. Clean and lube it. It can get gunked up and not operated smoothly. I would check both of these items before shopping for parts. If the down lock has never been replaced there's a 99% chance it is wallowed out and needs to be replaced.
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