The International Cessna^® 170 Association

Hope I'm not asking a question the has already been answered several times over however I have an issue. I had previously posted an issue I had with the Scott 3200 bushing sleeve on the 3200 head. That was solved with feedback from Bruce and George and when affixing the tailwheel assembly all went well until I looked at how the fork and wheel were centred to the mainspring. The fork/wheel appears to be perhaps 5-10 degrees off centre. I know this wasn't the case before I went about rebuilding the tailwheel assembly using a NOS 1958 Fork, keeping the existing 3200 head, and replacing all internals with either Alaska Air Frames, or Spruce internals. I installed a new bent arm control arm , and when I centred the assembly so it appears that the control arm is as close to 90 degrees to the main spring , the fork and wheel are deflected about 5- 10 degrees...to the RH ..passenger side. My engineer (AME) assembled the tailwheel , so should be correct. Can anyone provide an opinion...I would appreciate it. Mike

Mike, one of my first maintenance issues with 1304D was exactly what you have experienced with your tailwheel assembly, we replaced complete mailspring assembly pack, rebuilt 3200 assembly & replaced with new 6 ply tailwheel tire. Flew it 40 hrs but was bugged by the tweak in the fork, ended up replacing fork with the Alaskan Airframes wide fork & 400 larger/wider tire, things look straight now .

Mike,

Hard to see in the pictures exactly what your describing. If you are saying that the fork is not 90° from the control arm that is set by 3 things. We will suspect your new parts first.
1. The cutout in in the control arm represented in blue, must be clocked correctly so when the paws engage it the fork is held clocked correctly. This could be off from manufacture. You could temporarily flip the control arm over and see if the angle changes to the other side. This would prove this alignment is not right.

2. The paw or spring in yellow in this drawing might not be symmetrical meaning the paw is not mounted flat to the fork or the legs of the paw are not equal length. This would change the clocking.

3. The machining of the fork to hold the paw in green may not be clocked correctly. Compare the flat the paw is mounted to to the wheel axle represented by the two red lines. This must be aligned.

Any small discrepancies in any of these places will misalign the fork. You will have to disassemble and inspect each part very very carefully. I'll be you find the issue.

Not convinced that this is any more than a cosmetic issue. Most likely just a tolerance stackup.

sfarringer wrote:Not convinced that this is any more than a cosmetic issue. Most likely just a tolerance stackup.

Yep could be all the tolerance differences of the 3 parts I mentioned are on one side hence noticable alignment issues.

If you connect the steering cables up to Tailwheel do you get the same problem?

Thank You for the excellent opinion. I will work through the list and report back. Mike.