Cessna nose wheel shimmy repair
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- čas přidán 28. 08. 2024
- Rebuilding or replacing your shimmy dampener alone may solve your nose wheel shimmy problem for a while, but you're really just treating the symptom! Getting the interplay tolerances between all the interacting parts to a minimum, is the key to eliminating shimmy and reduced vibration, putting your airplane in line for better centerline tracking, more comfortable takeoffs & landings, plus ultimately & arguably, safer flight!
I just did this repair to my 172 XP - I wanted to add that the hardest part of the job is getting out the old bushings, and I found a method that makes it much easier: 1) thread the inside of one bushing. This will be hard to do; the bronze will grab your tap. Use lots of lube and make about a 1/4 turn at a time, backing up each time to clear chips. Oil is essential. My 172 has a long steel inner bushing that is 5/16" O.D., and a 3/8" tap threads that size without any further drilling. You only need about 4-5 threads. 2) Screw a bolt in from the outside end (obviously) and snug it up. 3) Now you can slip a smaller bolt through the OTHER bushing and push the first bushing out with a press. I thought 5/16" was too small for a pusher, so I drilled the second bushing out to 3/8" and used another 3/8" bolt to push with. I tried using the original long steel inner bushing to push with, but it deformed and I was afraid it would get stuck. 4) Use appropriate-sized bolt to now push out the second bushing. Sorry - I maybe should have done a video, but yours is so good I thought this was all it needed.
We do numerous aircraft being a maintenance facility, and just drill off the shoulder of the large bushings with a 1/2 " bit, and the smaller middle bushing shoulder with a 5/16 bit. Then push out both bushings the same direction using appropriate Snap On deep sockets. Also remember that the new spacers slipped into the bushings on the upper and lower sets, are by design, longer that the bushings, and the brass shims have to be installed before slipping in to the recess.
New tire. balanced tire, trued tire, shimmed steering collar!! rebuilt damper. Fixed mine.
I sold that POS... it tried to kill me twice. PPG is 1/20th the price and WAY MORE FUN.
Dude, randomly stumbled on this video looking for videos of how to install the front wheel fairing on a 150. Didn’t even realize it was you until half way through. I was like “damn this dude sounds familiar” lol
Haha
One of the biggest culprits is the steering collar. The steering rods can hide this somewhat. Put a tow bar on the nose and rock it back and forth. watch for the collar uniball lugs moving up and down. Any up and down movement will allow shimmy. Shims are available from Cessna to tighten up the steering collar. The nose strut has to be removed completely to install shims. I'm a 45 year A&P and have done this many times. As to an owner pilot doing work see FAR part 43 appendix ? For a list of what an owner pilot is allowed to do. If you do any work you are required to make a log book entry complete with date, work done, instructions used( maintenance manual or other approved pubs), signature and pilot license number.
I always tell people the Shimmy Damper's job is to keep a shimmy from shaking the nose wheel off the airplane. The shimmy is never "caused"by the damper being bad. It's always due to a loose scissor tolerances.
Great Job! I have the same problem with my Piper Tomahawk PA38 112. Upper and Lower links are not tight and cause shimmy. I ordered new parts to repair the problem as you did. Will update afterwards.
Well good luck. I sold the ol' 150 after she tried to kill me twice. I sold the 210 after I lost my medical. I sold my soul when I found paramotoring. I'll take new paramotor gear over 50 year old G/A equipment any day of the week, any weather, any flying event. I can buy new gear every year for less than annuals used to cost me. I have more fun than I ever did after owning different airplanes. Unfortunately, I've written off most of the general aviation community as a bunch of pompous self important jerks YMMV. For whatever reason I still keep my CFII current, but the thought of ever using it beyond helping friends sends chills down my spine.
@@YankeeinSC1 sounds like you're contributing to the problems with that attitude.
@@SoloRenegade Well I certainly didn't start out that way, but I flew my airplanes at my private (residential airpark) airport for 15 years. Never so much as had the nose wheel deviate from the centerline of the taxiway. I kept my mouth shut as other pilots crashed into the end of the runway, ground looped into the wind sock, broke numerous FARs, crashed on the adjacent road to the housing development, had airplanes fall off of jacks at anual , roll down hills & into the woods, setting the woods on fire, get killed on cross countries to places away from home...never said a word. But the day I bought paramotoring gear? I became the idiot? People like you...
@@YankeeinSC1 "But the day I bought paramotoring gear? I became the idiot? People like you..."
Wrong
First, who cares what others do? if they want to be idiots, let them. stop acting like you can save the world. you're not god. let it go. How old are you and you still haven't figured this out?
Second, I don't care if you paramotor or not, or fly ultralights or whatever. I support all facets of aviation. It's morons like you that ruin it for everyone else. You making baseless false accusations against people you don't even know is worse behavior than anything you complained about others doing. You are the problem, not them. Probably best you're no longer active in fixed wing aviation with that attitude.
You behavior is that of a very sad and pathetic person. Stop taking your problems out on everyone else. They say, "misery loves company", and you are misery incarnate. Stop trying to make everyone else as miserable as you are. You can only control your own actions in life. Grow up, and stop being a old grouch.
I've found play between the steel tube bushing and the fork ears, especially on older equipment. Made my own stainless steel shims to go in there first, then add the standard shims (made with stainless-I found brass wears too quickly). Never had a damper issue in itself, (if the shaft seals are good) only in the mounting holes (reshim or rebush as required). I worked on 172's and 150's for years, and never had ANY shimmy problem after I got a hold of it, something I am quite proud of with all the trouble the nosegear can cause.
brass is SUPPOSED to wear. if you use things that are too hard, then something else wears. You want the wear item to be the softest.
2:10 it's unfortunate, as that's the whole part that matters. undoing bolts is no big deal.
Tripods: exist
You missed one important step. Dynamically balance your nose wheel. You won't believe how much those old cast rims are out. Thus, not wearing out your torque links and steering components as fast.
How, please?
What's the cons about only adding thicker shims to correct this?
must order it for mine thanks
The shimmy damper only dampens the shimmy when it happens, It does NOT prevent the shimmy. Replacing the bushings like you did will fix the problem
You can do all this and it probably will still shimmy .
it was after all only a 150...but this kit helped significantly. Never had shimmy problems on any of the bigger planes I'd owned. I'd flown an occasional airliner or two every year that had something going on but that was more often a wheel bearings or wheel balance issue.
Is this something I can do on my own, I've kept a aluminum foundry running for almost 30 years all by myself, I've changed out more then a few bushings in my Day. I'm buying my friends 150 this week, just flew it yesterday and it has some also, who would be any the wiser anyway
indianchief741 I suspect what you are asking is can this repair be legally done by a pilot/owner under the provisions for owner preformed maintenance of FAR 43.3(g) and 43.7(f). I am not a lawyer and I don't play one on T.V., but I would say "not likely" without at least being done under the supervision of a licensed A&P mechanic. Who'd be the wiser? 1) An insurance company conducting a post accident investigation. Especially if they were being sued by a passenger of yours if that person was injured in an accident. 2) The next potential buyer. Especially if he employs an A&P to survey the airplane for maintenance compliance before he purchases it. 3) The FAA if they ever were in suspicion that you were willfully violating established maintenance proceedures and protocol. I've seen them do a part by part compliance inspection, one nut and bolt at a time. How likely are any of the 3? I know owners that have experienced all of the above. In a nut shell, it's just not worth the few bucks you'd "save" by not getting a mechanic with the proper certification involved. If you'd rather do it your self, build an experimental homebuilt IMHO.
YankeeinSC1 ya, I get it, friend told me all 150's have it anyway , I'll fly it over to thunderbird where a A&P buddy can watch. Thanks
should be loose enough to fall under its own weight.. but no side play. damping happens fast..and the links should do this without resistance.
Didn't see any grease on the bolt through the bushing, or in the moving part areas. Why not?
Very interesting. Shimmy is a difficult problem to solve in aircraft I care. I'm from Brazil, and i work in a aviation school. The kit has a Part Number?
mcfarlaneaviation.com/pdfDocuments/Torque%20Link%20Kit%20Eligibility.pdf
what part numbers for the kit? or what is the kit called on mcfarelane? TIA
no idea... sold that airplane about 9 years ago. Good luck
Has anyone seen sheared rivets on the upper flange?
I installed the McFarlane kit, rebuilt the shimmy damper, and even replaced the front tire on my XP. There is still occasionally a small amount of shimmy. Two questions: how much of a part does tire balance play, and how tight do the shims have to be? There is still a tiny amount of side-to-side rock in the scissors, but the bushings are brand new, as is the bolt, but I couldn't figure out how to get the last shim in place because it bent when I tried. Thoughts? I know AN bolts are a little undersize; what about close-tolerance bolts? The bushings should stop the rocking without the shims, so I wonder if my time would be better spent there.
Yeah - I'd like to see the answer to your question as well. I have a cherokee 180, and have a terrible shimmy on take-off. There is considerable play in the scissor-link, so I think I may go the route this video talks about first.
McFarland has a sheet on their web page on how to end the issue. Includes balance on the wheel, and sanding the tire.
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