C-170B Tailwheel spring Length

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DaveF
Posts: 1562
Joined: Sat Nov 03, 2007 1:44 am

Re: C-170B Tailwheel spring Length

Post by DaveF »

It might help to remove the entire stack, pre-assemble, then install as an assembly.
Absolutely. Having done it all of one time, I feel qualified to give the following advice. 8O The two keys to the job are order of (dis)assembly and using a C-clamp to squeeze the spring stack. You want to avoid letting the stack expand and wedge in the tail bracket, so first thing put the clamp on the stack as close as you can to the tail bracket. Then remove the U-bolt and loosen the AN3 bolts along the sides of the channel. I left the forward two AN3 bolts tight. Remove the big bolt last. The spring stack should slide out. I made the mistake of first pulling the big bolt and U-bolt, thinking I could just slide the main leaf out. No way. With the clamping forces removed the spring leaves will spring apart and wedge everything in place, so keep the stack compressed with the C-clamp.

By removing the entire stack you can inspect each leaf, clean up, apply anti-seize, etc. as needed. It's not a job that gets done often, so you might as well do it when replacing the main leaf.

On reassembly, stack the leaves, insert the bushing, then clamp the stack together. Clamping below the main bend, the leaves will want to shift a bit, so use the big bolt and bushing to keep them lined up. Slide the stack into place in the tail bracket. Check that the spring stack is the right thickness for the channel height and shim as needed. If you're unlucky, the new stack will be too tall and you'll have to loosen the forward two AN3 bolts to make a little more space. Then install the big bolt, torque it, install the U-bolt enough to pull the channel into place, tighten the AN3 bolts, and final torque the U-bolt.

Worked for me. :D

Dave
N5796C
Posts: 16
Joined: Thu Nov 20, 2008 3:09 am

Re: C-170B Tailwheel spring Length

Post by N5796C »

OK,

I've got the ARi L-19 bracket installed on my 170a. However, the origianl spring stack is too thick??? 3 springs almost fit perfectly?? Any ideas?
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