Shimmy Strut

[Pete Somers]

We used to put the nose on a jack and lift clear of the ground, chock behind both main wheels and put the u/c lever up and pump the gear until the nose gear unlocks. The shimmy damper is easy to get to then. The mains cannot unlock and go up due to the weight of the airplane.

Pete

[skymstr02]

Are we talking shimmy dampner or nose strut here? The dampner is on the top of the gear.

[Skymaster337B]

I asked about the nose wheel shimmy...sorry for any confusion.

[skymstr02]

Before you tackle the shimmy dampner, you need to do a few basic troubleshooting items first:

• Make sure that the nose tire is inflated to specs.
• Make sure that the nose wheel bearings are no defective or the axle bolt is too loosed.
• Make sure that the nose tire is within balance.
• Make sure that the nose gear torque links do not have excessive play.
• Make sure that you don't have a warped main gear brake disc.

This will eliminate some of the more common causes of nose gear shimmy before you tackle the dampner. Usually the Skymaster shimmy dampners work for many years without any difficulty.

[Ernie Martin]

However, I have found an easier indicator that it is the dampner: if it happens only when the dampner is hot. I've had to overhaul the dampner once on each of my two Skymasters and each time there was no shimmy on the first takeoff of the day (especially if it's a cool morning) and shimmy when you landed on a hot day (I'm in Miami) or if you took off soon after a hot landing (remember that the dampner is close to the front engine). One other thing: if the housing is sound, your A&P can rebuild it using the seals shown in the parts catalog.

Ernie

[Kim Geyer]

You can also connect your tow bar and turn the nose gear left and right, if the dampener is low on fluid it will make a squirting sound.
Kim

[Jim Rainer]

I had this problem about a year ago and my mechanic convinced me to change the front tire first and if that didn't work, he'd pay for it. It worked! The old tire looked OK but his knowledge of the problem told him that he had worked on lots of shimmy dampners first then find out all that was needed was a new tire!