starting to get the dreaded front wheel shimmy

[rbridges]

I looked up some old threads, and it seems that the steering horn and some of the bushings may be the culprit.  Before I plunk down a lot of money on the LASAR mod, is there a way to lift the front and get an idea where the problem is.  I've only noticed it a few times, but yesterday was a little more pronounced than the other times.  I'm guessing that braking and shifting the weight towards the front exacerbates the shimmy.

 

Anyway, any info I can get before my IA looks at it would be great.  If it gets to be a little messy, I'll probably take it to Cole to inspect.

[N201MKTurbo]

Just put it up on jacks. You'll figure it out.

Check the trunnion bushing by moving the nose gear side to side (not steering rotation) and fore and aft. It should be rigid. If you pull the gear forward you will extend the over-center link. This is ok.

Next check the steering horn by having someone hold the rudder pedals in a fixed position. Try to rotate the nose wheel it should be rigid, it probably isn't.

[rbridges]

thanks for the input.  I'll guess I'll raise it up and see how much play is in it.  

[rbridges]

Yep. That almost assuredly is your problem. I went through this a few years ago. Rather than the LASAR mod I elected to just do a repair exchange of my original design steering horn. It is good for several thousand hours and will most likely "get me through". Dan at LASAR sent me everything that I needed. I think that it took around four hours to install.

Jim

 

any particular reason you had the exchange instead of the mod?  

[rbridges]

The mod costs over a grand just in parts. Overhauling what I had was half that.

At the rate that I fly any form of the repair will probably last me the rest of my life. The mod may be better but it just seems like a solution to a non existent problem in my application.

Jim

 

thanks, Jim.  Sounds good to me, too.  If I can get a few thousand hours out of it, I'll probably be pushing up daisies by then.  I'll give them a call, but I assume they let you send in your old parts afterwards?

[Hank]

Yes, you give them a core deposit which they will refund to you when you send them your core.

This is how LASAR sold me a replacement part for my nose gear when the link to one of the doors broke. They were extremely fast with the core credit, too, applied to the CC used to purchase it from them.

[Wakeup]

I think my nose wheel shimmy is fixed for now. Took my first flight over 100 nm to the mechanic that did the annual on my M20B before I bought it and he re-balanced the front tire (which was out of balance) and tightend the front end bolts. I was able to taxi for the first time over 15mph and landed without any problems. Not sure how long it will last but for $150.00 I am happy. It was a great day to fly. I am celebrating with a drink. Cheers!!! Troy

[Guest]

Check out s/b M20-202. It covers setting of the nose gear castor angle which also effects steering and shimmy troubles.

Clarence