chan65 Posted August 15, 2019 Report Share Posted August 15, 2019 Trouble finding this maybe someone knows - what should be the movement on this chain? Is their adjustment , can’t find in manuals and tech support hasn’t called back in several days J model 79 Quote Link to comment Share on other sites More sharing options...
carusoam Posted August 15, 2019 Report Share Posted August 15, 2019 Adjustment is on the other side of the floor... You may find a dead spot about an 1/8” after a few thousand hours of use... there is a thread with pics and probably procedures... Followed by bigger challenges, old grease chunks in the system... including its gearbox in the back... What tech service did you call? There is also a maintenance manual and a parts manual that give some good hint at what this looks like... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Guest Posted August 15, 2019 Report Share Posted August 15, 2019 2 hours ago, chan65 said: Trouble finding this maybe someone knows - what should be the movement on this chain? Is their adjustment , can’t find in manuals and tech support hasn’t called back in several days J model 79 It’s in the maintenance manual chapter 27. Clarence Quote Link to comment Share on other sites More sharing options...
carusoam Posted August 16, 2019 Report Share Posted August 16, 2019 Way to go, Doc! Thanks for sharing the details. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
PT20J Posted August 16, 2019 Report Share Posted August 16, 2019 Ever notice how Clarence's answers frequently point to the Maintenance Manual or IPC? There's a message there somewhere Maximum tension without binding. Now there's a specification for you! Actually, it tells you something about the design -- this is not a precision piece of equipment. First, the trim wheel shaft bushing is not a standard oilite bushing as you might expect. It's a custom Mooney part made of hardened brass (I asked) with no provision for lubrication. The chain force causes the steel shaft to wear the bushing oblong which will result in noticeable wobble of the wheel and also makes the chain adjustment less precise. I replaced mine, but even the new bushing is a fairly loose fit. Adjustment is done from underneath. You have to loosen the four gearbox mounting screws and then turn the adjusting cap screws. Then you have to climb up in the cockpit and check the tension. Back and forth a few times -- good exercise. Better to get a helper. But wait -- there's more. When you get it just right you tighten the mounting screws and it changes the tension. Arrrrrrrrrrgh!. After a few tries, you think it's right and then you rotate the wheel through its range to try it out and guess what? The sprockets are ever so slightly eccentric so it's tight on one side and loose 180 degrees out. Mooney says to lubricate the chain with grease. That makes no sense as the grease won't get into the chain rollers. Some light oil on the chain and shaft works well. Check it every annual. There's a chain in the back for BK elevator trim too and there is a carrier bearing there which is supposed to get greased annually and is often overlooked. Mooney factory folks respond best to email, I've found. Skip 1 Quote Link to comment Share on other sites More sharing options...
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