Quick question - looks like I have to take the thing apart for a close look (and it has been many years since I have one of these apart, so I forget), but if you turn the t/w to the right and the steering arm moves as expected, but if the arm doesn't move to the left, that is the pawl, right?

Probably not the pawl itself. More likely it's the U-ish shaped piece of spring steel. Sometimes you can just bend it back, or you can buy a new one. Also the housing could wear a bit where the spring is supposed to catch. If it's been years since it's been apart, you might benefit from a rebuild kit from Airframes Alaska.

asa wrote:Probably not the pawl itself. More likely it's the U-ish shaped piece of spring steel. Sometimes you can just bend it back, or you can buy a new one. Also the housing could wear a bit where the spring is supposed to catch. If it's been years since it's been apart, you might benefit from a rebuild kit from Airframes Alaska.

Yes, what he said, it’s called a “compression spring”. Here’s a link: https://www.airframesalaska.com/Compres ... 432-00.htm.

That’s PROBABLY what’s going on, but I’d order a rebuild kit from Airframes Alaska. It may not have every part you’ll need, but having those parts on hand down the road that you don’t use this time is great. That steel spring was bent on mine at annual, and the housing had a wear mark on it that needed cleaning up. Works great now.

MTV

Here is a great video describing on how to disassemble and inspect the tailwheel. Steve also has assembly video and others posted all worth reviewing. https://www.youtube.com/watch?v=S-0i2MTe-A0 Several things could cause your issues including just being dirty. Don't try to grind the ends of the pawl to make it work better. You will just make it shorter and you tailwheel will have to swivel further to unlock. You can polish the ends with a buffing wheel for a smoother unlock, that is a trick I learned from the Airframes crew. Grease/temps makes a difference also, I use Aeroshell 22 works great at -20 to 90 degrees.
DENNY

Those Scott t/w videos by Steve Pierce are great,
but keep in mind he is rebuilding a 3200 tailwheel--
a 3400 is slightly different.

Sounds like a t/w teardown is long overdue--
I tear mine down every year to clean, inspect, & lube.
Sounds like your compression spring is not properly engaging the notches in the steering arm.
You can bend the spring arms outward to engage better.
Be sure & dress the ends to eliminate any burrs or whatever.
You can also reshape the notches in the steering arm with a little file.
Or you can just buy new parts.
Unfortunately the manufacturer is pretty proud of all that stuff & charges accordingly.

hotrod180 wrote:Those Scott t/w videos by Steve Pierce are great,
but keep in mind he is rebuilding a 3200 tailwheel--
a 3400 is slightly different.

Sounds like a t/w teardown is long overdue--
I tear mine down every year to clean, inspect, & lube.
Sounds like your compression spring is not properly engaging the notches in the steering arm.
You can bend the spring arms outward to engage better.
Be sure & dress the ends to eliminate any burrs or whatever.
You can also reshape the notches in the steering arm with a little file.
Or you can just buy new parts.
Unfortunately the manufacturer is pretty proud of all that stuff & charges accordingly.

Good advice all.

MTV

hotrod180 wrote:Sounds like a t/w teardown is long overdue--
I tear mine down every year to clean, inspect, & lube.
Sounds like your compression spring is not properly engaging the notches in the steering arm.
You can bend the spring arms outward to engage better.
Be sure & dress the ends to eliminate any burrs or whatever.
You can also reshape the notches in the steering arm with a little file.
Or you can just buy new parts.
Unfortunately the manufacturer is pretty proud of all that stuff & charges accordingly.

Thanks Hotrod. Yeah, time to take the thing apart. I swung by the hangar earlier and looks like I have a bunch of Scott parts from years ago. Also need to order some grease as the old can leaked all over the place. Will order another can of Mobil SHC-100.

Turns out it was the the u-shaped spring; it broke.
By the way, how many springs you guys have inside your 3400? Mine stock t/w has two. There are four holes - you guys running four springs or two?

I run four, the max in my XP Mods tailwheel.
And I have two p/n 3407-00 spacers under the big bearing on top.
I liberally grease all the internal parts.
I snug up the kingpin nut, then back it off one flat.
Works smoothly with no shimmy.
BTW don't forget to grease the bearing up inside the fork at the very bottom (just above the nut).

Hotrod - yeah, that bottom (small) bearing popped right out with a slight tap of a drift. I had two spacers as well. I will put some grease on the phenolic and metal spacers. What does four springs vs two do?

More springs mean you can get a higher bearing preload force before bottoming out the kingpin nut. For example if you were getting shimmy, you could try adding more springs and tightening the nut. Tightening with fewer springs means the preload force will be lower while tightening until it spikes at the end when the springs start to bottom out. Generally steering would be easier with a lower preload and looser nut. If you were happy with the function before, I would keep it how it is.

The grease fitting on the head doesn't push grease throughout the internals very well. I would basically dunk every component in grease while assembling then clean off the excess once assembled. Properly lubed means you can run the whole thing tighter without shimmy or steering problems. Loose parts move, wear, and break. Well fitting lubricated parts last forever.

I agree with Asa.
Except that adding more springs doesn't actually pre-load the bearing.
That's what the spacers under the top bearing ("quantity as required") do.
Ideally, you get the bearing loaded just enough to prevent shimmy,
and the springs providing just the right resistance to turning,
at exactly the same point.

I would say add two more springs, but (like Asa said) if it was working well,
maybe you should just leave it as is.
"If it ain't broke, don't fix it".