The International Cessna^® 170 Association

As a follow-up to Bruce's topic at the recent convention forum, I'd like to relate Angela's and my experience on our return trip. Funny how timely that forum topic turned out to be!
When we bought the plane it had compression springs at the top of the chains on the tailwheel and we never had any issues with the Scott 3200 operation or steering, although the steering did leave something to be desired as often seems to be the case. Our annual inspection was just prior to convention at which time I greased the wheel and decided to adjust the chains tighter by one link upon advice from our IA. Bad idea! The wheel started having trouble, and then completely stopped breaking in one direction. Some of you can now see where this is going, but I'll continue.
At the convention we tried a couple of times to push the tail through the break, as did a couple of other people. This turned out to be a baad thing. After the convention, as Angela and I landed and tied down for a planned overnight in the Omaha area we found the tail wheel to be going flat. There we were Saturday evening at a small airport with a flat tire. Well, someone was looking out for us because eventually a seasoned tailwheel owner who happened to be on the field at the time was informed of our troubles and brought us a used tube to get us back in action. The pushing on the tail must've rolled the tube inside the tire to the point of chaffing a hole next to the valve. At any rate, we were very lucky at this point since no damage occurred to the rim or plane in any way- just the flat, and we got that fixed pretty easily.
Back home now and the tailwheel came off. Once I had it in my hands I could see the problem. The compression springs had bottomed out too many times causing the arm assembly on the bad side to bend upward at such an angle that it couldn't turn far enough for the wheel to operate properly. Normal operation means the wheel must be allowed to turn far enough for the pawl to push and disengage the spring allowing the wheel to castor. Boy, did I feel foolish for not catching something so basic sooner. After replacing the inner spring, pawl and assembly arm, it now works like a charm. I've attached some pictures to show the angle of the bent arm that had formed compared to a new arm assembly and the cracks that were forming on that arm. Oh, and the compression springs are history too!
Bruce thought I should post this story to share the experience, so I hope this can be informative and/or interesting.

For those of you using tension springs from Aircraft spruce, are you using the "light duty" or "heavy duty" springs? I purchased the light duty springs (2151 springs) and they seem to be a little too light. I know the 170's have some trouble with ground handling but these springs just don't seem to get the job done. They might be fine for a 120 or 140 but seem a little small. The heavy duty springs looked way too big for a 170 but I wonder if they would be any better. I think the bag said it was for a 190.

Can you give a PN? Or link? or illustration as to which springs you are mentioning?

My replacement springs came from Univair (U3239A-001) and don't indicate heavy or light duty that I can see. Looking at them I'd guess heavy duty and remember seeing similar springs on several 170s at Duluth.

This thread has all the information you need about the correct tail spring to get including a picture.
http://www.cessna170.org/forums/viewtop ... ing#p51529

I know I'm going to catch some flack about this.....But don't use compression springs....a properly maintained Scott 3200 only needs tension springs, as designed ......Brad