201Steve Posted June 17, 2019 Report Share Posted June 17, 2019 Howdy folks, I have some issues with the trim system on my '77 J. The wheel gets very tight and hard to turn, right around the takeoff setting. I've been dealing with it for a little bit, but I know it's stressing the electric trim and it's a real nusance when trying to trim on the fly in the critical phases of flight. My Mooney mechanic traced it to the jack screw and the price for a new one is like $1,700. Any suggestions where I could perhaps source a used one? I've only had it for about 7 months so I'm not familiar with what outfits might be the Go-To on something like this. Thanks for any feedback! Quote Link to comment Share on other sites More sharing options...
Hank Posted June 17, 2019 Report Share Posted June 17, 2019 Before replacing it, just open it up and remove all of the old grease. It's probably hard and chunky. Refill with fresh grease. There should be a thread here somewhere about doing this, and maybe something on Maxwell's site, too. If your A&P is unsure, visit an MSC. Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted June 17, 2019 Report Share Posted June 17, 2019 Are we sure it needs to be replaced and cannot be repaired or relubed? There are all sorts of threads on MS about the jackscrew grease turning to rock... Quote Link to comment Share on other sites More sharing options...
RobertGary1 Posted June 17, 2019 Report Share Posted June 17, 2019 yes be sure you're really sloping on a lot of grease on both the jackscrew just behind the trim wheel and the jackscrew in the tail. Run the trip all the way in both direction and grease. -Robert Quote Link to comment Share on other sites More sharing options...
Guest Posted June 17, 2019 Report Share Posted June 17, 2019 There’s a guy on Mooneyspace with a used one, he goes by 201Steve! All kidding aside as others have said it likely needs disassembly cleaning and some new grease. Clarence Quote Link to comment Share on other sites More sharing options...
201Steve Posted June 17, 2019 Author Report Share Posted June 17, 2019 My mechanic is a MSC and did re-grease it, said that he'd never really seen one act the way mine is. You can stick your hand in there and feel that the threads are almost "sharp" compared to a normally functioning one where the threads on the screw are more smooth feeling. Quote Link to comment Share on other sites More sharing options...
Yetti Posted June 17, 2019 Report Share Posted June 17, 2019 There are about 5 u joints that are in need of a good cleaning and greasing. Also the chain on the trim wheel can be junked up with hard grease. Quote Link to comment Share on other sites More sharing options...
Vance Harral Posted June 17, 2019 Report Share Posted June 17, 2019 The thread you want to read is here: My guess is that when your mechanic "re-greased" the jack screw, he just slopped some fresh on the jack screw shaft, through the opening in the empennage. That's fine for regular maintenance, but once every 10 or 20 or 50 years, you've gotta pull that thing out, disassemble, and clean/re-grease it. Among other things, it provides an opportunity to check the bearings which the shaft goes through. 2 Quote Link to comment Share on other sites More sharing options...
Sabremech Posted June 17, 2019 Report Share Posted June 17, 2019 Just now, Vance Harral said: The thread you want to read is here: My guess is that when your mechanic "re-greased" the jack screw, he just slopped some fresh on the jack screw shaft, through the opening in the empennage. That's fine for regular maintenance, but once every 10 or 20 or 50 years, you've gotta pull that thing out, disassemble, and clean/re-grease it. Among other things, it provides an opportunity to check the bearings which the shaft goes through. You beat me to it! Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 17, 2019 Report Share Posted June 17, 2019 You don’t replace the jackscrew because it is too tight, you replace it when it is too loose! You can take the ball bearings apart, clean and re-grease them too. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.