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Looking for a Nose strut Shimmy Damper for my C-150M.
Any advice on where to find one decently priced is also greatly appreciated.

Thanks in advance,
-Brooks

Check with Lord or McFarlane. Both are Fly-In sponsors.

Have you considered rebuilding yours? You can replace the o-rings and hydraulic fluid. If the chrome plating is coming off inside you’ll be rebuilding them more often but once you get the process down it’s a 30 min job.

I have one you can have if you still need it. It's the original one from my plane. I replaced it with a dampener from McFarlane.

Richard, how do you like the McFarlane dampener?

I am with Geoff. I would like to hear your views on that dampener also.

Jay

Geoff and Jay,

I have some questions, suggestions, and comments.

Questions:

Why do you want a shimmy dampener?

1. Is your plane missing a dampener? If you are restoring a plane that doesn’t have a dampener, or for any other reason you want a new one, your choices are somewhat limited. The Cessna shimmy dampener (0442512-1) is not currently available from cessnadirect.com (Yingling Aircraft, Wichita) or from cessnaparts.com (Hill Aircraft, Atlanta). That leaves you with two choices: McFarlane or Lord. Aircraft Spruce has the McFarlane unit for $827 and the Lord unit for $889. The Lord dampener used to be several hundred dollars higher than McFarlane. There seems to be many dampeners on eBay, but they may not be in any better condition than the one you already have.

2. Is your dampener leaking? McFarlane has seal kits with all the o-rings you need for repair. They also have kits that include the o-rings, a new shaft, and snap rings.

3. Is the dampener damaged or worn out? An initial check can be done with the dampener on the plane. Remove the bolt at the end of the shaft. Push or pull both directions on the shaft. Don’t pull the shaft so far forward that the other end of the shaft goes inside the barrel because then the oil will run out. As you move the shaft fore and aft, you should feel some resistance since the oil is being forced through a small hole to the other side of the piston. (That’s what prevents the shimmy.) The resistance you feel should be smooth and not jerky, which may be indicative of internal problems. Then you will need to remove the dampener and disassemble it. If the o-rings are worn or stiff, they can be replaced. If the barrel is badly scratched or worn inside, you may need to replace the dampener.

4. Are you getting nose wheel shimmy? The first and easiest thing to check is the mounting bolts for both the dampener barrel and the shaft for excessive movement. (“Excessive” is a maintenance term for describing any unspecified amount.) The type of movement you don’t want a lot of is fore and aft movement of either the barrel itself or the shaft. There has to be some movement because the barrel and the shaft have to pivot very slightly on their respective bolts. The mounting holes should also be checked for wear.

That is about all of the problems that can happen to a shimmy dampener or that can be caused by the shimmy dampener.

Suggestions:

If you are considering a new dampener because of a shimmy, there are some other things to check before you spend big bucks for a dampener.

1. Check the condition of the torque links. Excessive movement can be caused by worn bushings, shims, or bolts. If the components are really worn, you can probably tell that by holding the links where the join in the middle and moving them from side to side. A more accurate indication can be made with the links separated at the middle. WARNING: Before removing the bolt, let the air out of the nose strut. Otherwise, the air pressure will slam the internal components hard against the bottom of the strut. (And, you may also get hurt.) With the bolt removed you can get even a better indication of the amount of wear as you move the links from side to side. McFarlane has torque link repair kits.

2. Check the tire for balance. McFarlane has information on their website about this. Their suggestion for out-of-balance is to use a belt sander to remove rubber while it spins the tire. I’m not going to do that to my Goodyear Flight Custom III nose tire.

3. Check the shims near the steering arm assembly on the strut. See the attached figure from the 150 maintenance manual. Replacing those shims seems to be what stopped the shimmy on my plane. I replaced them during the annual last February and have not had a shimmy since.

Comments:

I had replaced my shimmy dampener before I changed the shims. My initial consideration was the Lord dampener. It works by friction between a rubber piston and the body of the dampener. The Lord company claims the advantage of no maintenance and no change of effectiveness because of temperature changes. But, when the piston wears our, the dampener must be replaced. At the time I replaced the dampener the Lord dampener was considerably more expensive the alternatives.

The McFarlane website explains why their dampener is better.

Sometime in 2018 or maybe a little earlier, McFarlane announced their development of a replacement for the Cessna shimmy dampener. It was to have several improvements over the Cessna unit by using a larger diameter shaft and providing components for temperature compensation. I would check on their progress every few months and even talked to them at Oshkosh in 2018. Finally, the new dampener was announced, I believe, in August 2019. I ordered it immediately and was one of the first to get one. I installed it early in September. The new dampener helped a lot, but I would still get some occasional shimmy. In November, McFarlane notified me that they had made an improvement in the dampener and they would send me a new one. I installed it in December 2019. I still got some shimmy, but that went away after I replaced the shims.

Probably, the main reason I went with the McFarlane dampener was my previous experience with the company. I have installed the torque link kit, nose gear strut seal kit, fuel vent line, and fuel strainer standpipe, plunger, and seal kit.

I have also visited the McFarlane facility and got a tour. Fascinating place and great people. They are also a sponsor of the Cessna 150/152 Club. Let them know you are a member and you can receive their type club discount.

If you have any questions, let me know. I will try to give a brief answer next time.

Thanks, Richard, for the comments. Mine does not shimmy all the time, more like once in a while. But when it does it "really" does. It has been rebuilt so I would think that would take care of it but no. My annual is due the end of this month and will l take a closer look at it with your suggestions in mind.

Jay

You’ve probably solved your question - but after years of fighting shimmy I put on a Lords dampener. It’s never happened again. Not once.