Another gear rig question

[Taracka]

 have a C model and I’m curious, with the preloads set correctly per spec, how far from the latch socket do you start feeling preload resistance in the J-bar ( when lowering the gear) before you push the bar the rest of the way to the latch socket. I’m getting about a finger width between the J-bar and latch socket and wondering if that is typical.

thanks ,

  Rich

[RLCarter]

I saw about the same, took another 1/2 turn on the rods and was still in specs but took very little to get the J-bar latched

[Taracka]

I took another half turn (lengthened) on each rod and that caused the preload to be below spec so I returned it to the previous position.  It stands to reason that if the j-bar goes into the latch socket with no resistance past gear down, then there would be no preload, right?  Again, I’m seeing about 5/8-3/4 inch of travel between where the gear is down and where the j-bar hits the latch socket.  Since I inspect Mooneys on occasion And Since the maintenance manual doesn’t mention this, I’d like to have it straight in my head what is right,

[jasona900]

It sounds to me like you are in dangerous territory.  If the preloads are not set correctly, you could suffer from a gear collapse.  When you adjust one of the landing gear rods, you must check the preloads on all three landing gear.  I strongly suggest you have someone who is familiar with the correct setup of the gear check your work. 

[Taracka]

Guess i should’ve made my question more clear.  I checked all preloads and they are within spec.  I am an IA and have worked on Mooneys for 10 years.  My question (which isn’t answered in the Maintenance manual) is how much preload should be felt in the j-bar when the preloads are set within the correct range.  When I lower the gear and the j-bar initially stops, I get about an index finger space between the back of the j-bar and the latch socket seat before I push the bar the rest of the way to engage.  I’m looking for data from other j-bar Mooney owners more out of curiousity than anything else.  

 I have heard of gear collapses as a result of j-bar failure at the base and curious if the failure was determined to have been caused by incorrect adjustment and overstress of the j-bar at the weld joint or if maybe corrosion was a factor.

[takair]

I have never measured it at the J-Bar, but what you describe "feels about right".  J-bar starts to get stiff near end of travel, just before going in block.  Be sure that the springs on the main gear pushrods are compressing.  I had one that had seized up and getting pre-load correct was hard and the load on the J-Bar would go up drastically.  Both springs should compress roughly the same amount and that is some of what you feel as you get near the block with the J-bar.  I forget where they added springs to the nose gear, that may only be electric gear planes.

[1964-M20E]

IF you just bring the J-bar to the gear down position and leave it un-latched it will hover right a the locking block.  You then have to push it the remaining distance to lock it in.  The force needed is not that great to get it to latch.  Should you need to use your leg to assist you in getting it home in the block you probably have an issue somewhere.  If you just need to lean into is some with your upper body you are probably good..

As an IA I am sure you have sufficiently lubricated all the moving parts of the gear system.  Once on my former E model I started having trouble getting the bar into the gear down lock so after lubricating parts of the gear system that went away.

 

 

[Taracka]

Thanks guys for the helpful info and yes I lube and clean the gear religiously since I operate from a grass field and things get dirty quick.  Once The J-bar gets to the point where it starts to build resistance, I am able to latch it with one hand without much trouble and I don’t consider my arm to be particularly strong.  It might be interesting to measure with a scale for reference sake.  If I had to guess I’d say it takes maybe 25 pounds to reach the latch point but I’d just be guessing.