Papa K Posted January 27, 2022 Report Posted January 27, 2022 Had my first flight in my M20J today. The only issue I have so far is the electric trim is not working. Any suggestions where to start troubleshooting? Yes, the elevator trim switch was on. Quote
201er Posted January 27, 2022 Report Posted January 27, 2022 5 minutes ago, Papa K said: Had my first flight in my M20J today. The only issue I have so far is the electric trim is not working. Any suggestions where to start troubleshooting? Yes, the elevator trim switch was on. Trifow into the yoke mounted trim switch. Quote
Papa K Posted January 27, 2022 Author Report Posted January 27, 2022 13 minutes ago, 201er said: Trifow into the yoke mounted trim switch. ok - like a contact cleaner spray to see if the switch is making good contact. I'll try that. Thanks Quote
EricJ Posted January 27, 2022 Report Posted January 27, 2022 A trick I had to learn was to push the button down to make it work. This also disengages the autopilot on my airplane, so it wasn't initially intuitive. The airplane I was flying before just need the switch pushed forward or back, so it was new to me to have to push it down as well. Quote
Bolter Posted January 27, 2022 Report Posted January 27, 2022 Check the performance of your autopilot. On my J (so I assume all of them) the electric trim is through the AP, whether the AP is engaged or not. If you engage your AP and it is able to control pitch (you can see the trim wheel moving), then the problem is most likely your yoke switch and not something more drastic. FYI: Similarly, if you remove your AP for service, your electric trim will not work anymore. 1 Quote
ZuluZulu Posted January 27, 2022 Report Posted January 27, 2022 6 hours ago, Papa K said: Had my first flight in my M20J today. The only issue I have so far is the electric trim is not working. Any suggestions where to start troubleshooting? Yes, the elevator trim switch was on. Which trim system do you have? Quote
Papa K Posted January 27, 2022 Author Report Posted January 27, 2022 5 hours ago, ZuluZulu said: Which trim system do you have? Good question - I don't know. I figured it was factory. There is a trim switch on the left side of the yoke. Other than that, I will have to check the logs to see if there was a post-production trim put on. Quote
skykrawler Posted January 27, 2022 Report Posted January 27, 2022 Your absolute lack of knowledge will work against you. There must be some documentation that came with your airplane. A fundamental start would be what kind of autopilot is installed in your airplane? Typically J models all have an autopilot. Quote
OR75 Posted January 27, 2022 Report Posted January 27, 2022 4 hours ago, skykrawler said: Your absolute lack of knowledge will work against you. There must be some documentation that came with your airplane. A fundamental start would be what kind of autopilot is installed in your airplane? Typically J models all have an autopilot. not said in the nicest way ... but i agree with you Quote
skykrawler Posted January 27, 2022 Report Posted January 27, 2022 5 hours ago, OR75 said: not said in the nicest way ... but i agree with you True, but this airplane is flying with discrepancy. I apologize. 1 Quote
Papa K Posted January 28, 2022 Author Report Posted January 28, 2022 11 hours ago, skykrawler said: Your absolute lack of knowledge will work against you. There must be some documentation that came with your airplane. A fundamental start would be what kind of autopilot is installed in your airplane? Typically J models all have an autopilot. FYI - I've only owned it 2 weeks. It is the first airplane I've ever owned. That's why I'm here looking for help Autopilot is original Century 21. Quote
BravoWhiskey Posted January 28, 2022 Report Posted January 28, 2022 In my case the trim had no lubrication and trim required excess torque which burned out the servo... had servo and AP repaired and trim adjusted and lubricated. Quote
carusoam Posted January 28, 2022 Report Posted January 28, 2022 Often… The grease used to lube the trim system gets old… and needs to be cleaned out. The grease used, has a tendency to get wiped and collect at the ends of the ‘usual’ range a particular pilot has…. Very much a WnB issue… load the plane a different way… and the trim may need to break through some old cruddy grease… Old cruddy grease can turn into rocks… and pretty much make trimming a challenge…. There is a gear box in the system that may have decades old grease… PP thoughts only, not a mechanic… Best regards, -a- Quote
1980Mooney Posted January 28, 2022 Report Posted January 28, 2022 (edited) Did you see the comment above about pressing the rocker switch down while rocking it forwards or back? Pressing down energizes the trim. I looked at your panel pics on Aircraft.com. It looks like you have a yoke mounted switch like on my Century 41. Century 21 Manual https://www.centuryflight.com/images/operating-manuals/68S805.pdf Century 41 Manual https://www.centuryflight.com/images/operating-manuals/CENT41.pdf This description of the switch is from the Century 41 Manual. Edited January 28, 2022 by 1980Mooney 1 Quote
carusoam Posted January 28, 2022 Report Posted January 28, 2022 @Papa K check out the note above from 1980… -a- Quote
1980Mooney Posted January 28, 2022 Report Posted January 28, 2022 5 hours ago, Papa K said: FYI - I've only owned it 2 weeks. It is the first airplane I've ever owned. That's why I'm here looking for help This may help you. Service mooney.free.fr/Manuels M20J/M20J/Mooney Service Manuel M20J Vol. 1 of 2.pdf mooney.free.fr/Manuels M20J/M20J/Mooney Service Manuel M20J Vol. 2 of 2.pdf Parts mooney.free.fr/Manuels M20J/M20J/Mooney M20J Illustrated Parts Catalog.pdf POH - 2 one older that matches your plane and one newer which has some additional and better presented information. M20J-POH.pdf (nqac.com.au) M20J_3203B (e-monsite.com) Quote
65C_flier Posted January 28, 2022 Report Posted January 28, 2022 (edited) On 1/27/2022 at 1:02 PM, EricJ said: A trick I had to learn was to push the button down to make it work. This also disengages the autopilot on my airplane, so it wasn't initially intuitive. The airplane I was flying before just need the switch pushed forward or back, so it was new to me to have to push it down as well. +1. First flight after buying a 78J with Century III I thought the elec trim wasn't working until reading the Century Manual. After figuring out how to use it I decided it was too course and it annoyed me disconnecting the ROLL or HDG modes if I needed to trim. So now I just trim manually and leave the elec trim switch off. AP still works in all modes including ALT hold. Trim switch still disengages all AP modes. Edited January 28, 2022 by 65C_flier 1 Quote
Davo Posted February 19, 2022 Report Posted February 19, 2022 First posting on this forum. I just purchased a 1988 M20J. Electric trim went inop. 1 hour after taking possession during the flight home. Yoke switch appears to be working. KS-179 trim motor whirrs when switch selected but not turning the gear. Manual trim smooth and easy to adjust. First thoughts is shear pin or possibly a clutch? Anyone have experience troubleshooting this? Thanks in advance for your thoughts and sharing your experience. Dave Quote
Steve Dawson Posted February 23, 2022 Report Posted February 23, 2022 I had the same issue when I owned my J. Before you start spending money on repairs, open the inspection door on the side and locate where servo to trim tube is. There's a chain connecting the two and it sometimes starts to seize or just needs lubrication. Or when its cold it will contract. Try spraying some lubrication on it and manually exercise the trim wheel and see if that helps. I think I spend a couple AMU's until I figured that out. Quote
N201MKTurbo Posted February 23, 2022 Report Posted February 23, 2022 The trim servo has two circuits. One to run the motor and one to engage the clutch. It seems the clutch circuit isn’t working. I wouldn’t replace anything, I would find the broken wire or bad connection and fix it. Quote
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