The International Cessna 170 Association

I searched the forum but couldn't find anything... how much fore and aft play should there be in the tailwheel steering arm? I move the rudder by hand and the steering arm moves about 10 to 15 degrees before it catches and the spring starts stretching. I know that some play is allowed, but how much is too much indicating something is off in the tailwheel internals?

JimNelson wrote:I searched the forum but couldn't find anything... how much fore and aft play should there be in the tailwheel steering arm? I move the rudder by hand and the steering arm moves about 10 to 15 degrees before it catches and the spring starts stretching. I know that some play is allowed, but how much is too much indicating something is off in the tailwheel internals?

It sounds as if your steering “pawl” is excessively worn. There should be zero “play” between the steering arm and the “detent” and you can test that with your hand.

That makes a lot of sense. I can easily move the steering arm by hand quite a bit before it catches and moves the tailwheel. That may also be the cause of my "loose" rudder pedals mentioned in an earlier post. I was used to the feedback resistance from the tailwheel on the ground, and it now takes more travel to get things moving in the right direction. Time to get the local A&P to start taking things apart. Thanks!

Jim, you can do this yourself with common tools. The article being discussed in the other thread tells about the pawl replacement, but the exploded parts-diagram of the Scott tailwheel can lead you thru it. You will want a new “pawl” and new “Pawl spring”... which is a flat internal spring (bent at two places) which engages the pawl detents.

The exploded parts diagram makes things really clear. And, there's a couple YouTube videos showing disassembly: https://www.youtube.com/watch?v=S-0i2MTe-A0 and assembly: https://www.youtube.com/watch?v=X1uAd0KSnCc which also helped. I'll see if I can work under the watchful eye of our local A&P and see what's up. And maybe learn which end of the wrench to hold since I am a lot better with software than hardware. I'll report back with what we find. Thanks for the help!

A followup. My A&P/IA took everything apart expecting to just clean, inspect, and regrease. What he found was the tailwheel bearing fell apart. The steering arm had just an inch of play but that pointed to a much larger problem. I'm glad that I didn't accept this play as normal.

And another followup. After further cleaning, we found that the steering arm did indeed have a well-rounded detent. The pawl was very worn. As mentioned above, that was the cause of the steering arm play. Replacing arm, pawl, and bearing. While the bearing wasn't the cause of the steering arm play, without the pay I wouldn't have found out about the bearing.

JimNelson wrote:And another followup. After further cleaning, we found that the steering arm did indeed have a well-rounded detent. The pawl was very worn. As mentioned above, that was the cause of the steering arm play. Replacing arm, pawl, and bearing. While the bearing wasn't the cause of the steering arm play, without the pay I wouldn't have found out about the bearing.

Feels good when we accomplish these sort of things, heh?

Feels great! The first small step to really knowing the aircraft. Thank you and the Association for this incredible learning resource.