Rick Britton Posted January 7, 2016 Report Posted January 7, 2016 Shortly after purchasing a 67 F Model I experienced severe nose wheel shimmy on takeoff. Removed wheel and inspected tire, bearings and reinstalled. Next flight shimmy came back on landing roll out with no braking. Removed wheel, rebalanced, same result. Installed new tire, same. Prior to this we did 6 take off/landings with no shimmy and no prior history. Shimmy has been only on landing since first incident. Would appreciate any input to helping solve the issue. Quote
takair Posted January 7, 2016 Report Posted January 7, 2016 There are a few threads on the topic. Likely a combination of slop in you steering linkage. If you can move the rudder significantly on the ground, then the nose gear link likely has slop. The other thing is the castor of the nose gear. There is a Mooney SB out there to measure and correct this with a simple washer. It seems unlikely to work, until you do it. Typically the shimmy will occur when slightly light on the nose gear, like in flare. Search for shimmy and you will find threads with the call out for the SB. If you can't find it, feel free to PM and I will pull it up when I'm in the office. Quote
carusoam Posted January 7, 2016 Report Posted January 7, 2016 Welcome aboard Rick. This is sounding like a familiar challenge related to worn nose gear issues. Fortunately, the nose gear can be rebuilt if that is your problem. The search box is your friend.... be looking for the key words like... - Eight second ride - Lasar Mooney Service Center - Nose gear truss If you are experiencing the eight second ride, an overhaul of the nose gear truss may be the solution. Lasar is a place that can get that done for you. I am a private pilot, not a mechanic. Hope that helps, -a- Quote
tony Posted January 8, 2016 Report Posted January 8, 2016 Jack the airplane up, take the belly skins off (if you need to), and grab the front tire and move it side to side. See where the slop is. I would be willing to bet its the steering horn. LASAR has rebuilt ones on the shelf. Quote
MyNameIsNobody Posted January 8, 2016 Report Posted January 8, 2016 Laser has a brass insert and shims too. I did the insert and also put a couple shims in. Wilmar invoice me (I got a couple of all sizes) and charged me only for the two I used. Returned others. Didn't know what one's I needed... Quote
rbridges Posted January 8, 2016 Report Posted January 8, 2016 Jack the airplane up, take the belly skins off (if you need to), and grab the front tire and move it side to side. See where the slop is. I would be willing to bet its the steering horn. LASAR has rebuilt ones on the shelf. I had this problem a year or two ago. I noticed it mainly on landings. Jim (bluehighwayflyer) pointed me in the right direction. He told me to call LASAR and do an exchange. You can get an idea by grabbing your rudder and seeing how much side to side play it has. I think mine was 1.5-2 inches before replacing the steering horn. Afterwards it was about 3/4". 1 Quote
Guest Posted January 8, 2016 Report Posted January 8, 2016 Search Mooney SB M20-202, it covers nose gear adjustments. Clarence Quote
carusoam Posted January 8, 2016 Report Posted January 8, 2016 http://www.mooney.com/en/sb/M20-202.pdf Google found this. I was unable to find the service bulletins on the new version of Mooney.com Best regards, -a- Quote
mike20papa Posted January 8, 2016 Report Posted January 8, 2016 The steering horn has such short linkage pieces that any wear in ball links, loose ball links on rods, loose bolts, etc. can become a problem. If you can raise the nose wheel off the ground enough to wiggle the nose wheel back and forth while you look closely up in the gear bay, you may find the source of wear/play. Could be something as simple as a worn rod end or loose bolt. The phillips head screw facing fwd.just right of the steering arm - that attaches the assembly to the nose wheel truss has to be torqued tight - found that out, myself. Good luck. 1 Quote
rubixcube2k3 Posted January 8, 2016 Report Posted January 8, 2016 I recently had my nosegear inspected and rebuilt by Lasar. Price wasn't offensive, and turn time was amazing. I had a significant amount of slop in my Steering Assembly and while Taxiing, it was like driving one of those mid 1980 remote control cars with the caster center wheel on underneath. Take offs were "Exciting" to say the least. We lifted my plane and you could actually hear the grease sloshing when the nose gear was moved from side to side. It also had a considerable amount of freeplay in terms of left right movement along the horizontal axis. When it returned, it was amazing how well it performed on first taxi and take off. and even surprised me how deliberate the tracking felt on the ground on each landing since. Abe L. Harper, Jr. 1975 M20C N7463V - 1R8 Bay Minette, AL Quote
tony Posted January 8, 2016 Report Posted January 8, 2016 (edited) The steering horn has such short linkage pieces that any wear in ball links, loose ball links on rods, loose bolts, etc. can become a problem. If you can raise the nose wheel off the ground enough to wiggle the nose wheel back and forth while you look closely up in the gear bay, you may find the source of wear/play. Could be something as simple as a worn rod end or loose bolt. The phillips head screw facing fwd.just right of the steering arm - that attaches the assembly to the nose wheel truss has to be torqued tight - found that out, myself. Good luck. Rick that's the culprit in white. It wears out. If I were you, I would check that thing first before you do anything else. Edited January 8, 2016 by tony Quote
pinerunner Posted January 8, 2016 Report Posted January 8, 2016 Here's another site http://www.donmaxwell.com/publications/MAPA_TEXT/M20-202%20-%20Eight-Second%20Ride/EIGHT_SECOND_RIDE.HTM His publications are pretty good reading. Quote
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