Citabria/8KCAB Scott 3200 Tailwheel disassembly pics

Off a Google Search -

"Scott Aviation, formerly of Lancaster, NY, was the original manufacturer of Scott tailwheels. They also manufactured oxygen equipment for aircraft. If fact, oxygen equipment was the principal line of the company. They also manufactured brake master cylinders and a few other items for aircraft. In 2001, Tyco bought the company and move operations to Monroe, NC. Tyco also changed the name to Scott Safety. Apparently, Scott Safety/Tyco dropped the tailwheel line, as none of its currect product catalogs include tailwheels, and tailwheels are not included in its products listed on its website. Current products include the well known lines of Scott respirators used by firefighters. Tyco recently merged with Johnson Controls, and last month Johnson Controls announced that it is selling Scott Safety to 3M.

I have a pdf of an interesting 1955 Scott Aviation catalog containing both the oxygen equipment and tailwheel lines (along with their other products at the time) but the forum software wont let me upload it because its more than 1 Meg.

As for current options (aside from serviceable used or NOS Scott parts if you can find them), Airframes Alaska/Alaskan Bushwheels has picked up the ball and is manufacturing and selling PMA'd tailwheels, assemblies and replacement parts interchangeable with the original Scott tailwheels, assemblies and parts. The AA/AB replacement parts I've bought so far have been at least as good as original Scott parts. As a bonus, AA/AB uses the same part numbering scheme as Scott - they just prefix the part number with "ABI"."
 
Tailwheel troubles! Help! I tore down my tailwheel and found dowel pin #38 worn down, lower thrust washer #10 grooved from rubbing over the top of #38, lock spring #23 a little deformed, spacer #25 missing, and five each #8 springs instead of three like I am used to seeing.

I understand the ABW replacement for # 38 is a 1/2" long instead of 1/4" and requires drilling the hole deeper. Does anyone know of a source for the older style dowel? 0.25Dx0.235L. I'm thinking of grinding down the longer one.

If I pull out bushing #14 will pin #26 drive through into the bore?

I am thinking I am only supposed to have three each #8 springs instead of five for my 8KCAB. Am I correct?

After noticing the wheel bearing seals and bushings installed upside down, I noticed that castle nut #21 was ran so far up that the cotter was a thread or so below the nut. Looking a $140.00 into the future when I put this back together, are there any rules of thumb as to how tight to adjust nut #21?

I've got to learn to be less observant ABI-3200A-2.webpIMG_20220529_151615_HDR.webpIMG_20220529_160650.webpIMG_20220529_145709_HDR.webp
 
That spring looks horrible. I think Bushwheels is your only hope.

I taught a guy how to rebuild these things, then he got so good at it I forgot how. He was way better than me at it.

That nut is a shimmy damper. You tighten it only enough to stop shimmy.

I personally go easy on the grease. I assemble them with light grease, and the next time I think I need grease, I clean them out and re-assemble with light grease.

Every time grease goes into that zerk, we get a shimmy problem.

You do know there is a taper pin holding that spring? I don't think # of coil springs makes much difference. Not a Scott expert.
 
Bob Turner said:
You do know there is a taper pin holding that spring?
Click to expand...
I did not. What is the best way to get it out? On the dowel pin I drilled it and used an easyout. The #23 spring pin looks a little small and is in such an awkward spot for drilling.

FYI I did find where ABW offers a part # 3226 instead of the longer 232-04 Dowel pin to fit legacy Scott 3200 TW.
 
I would be curious to hear how many springs ABW recommends. I had one with five and one with three which my IA friend said to add two more to when it was apart.

The pin holding that little three sided spring in should push right out.
 
i believe so but I'm pretty sure that the bushing wasn't too hard to push out either. if you look in my photos, the bushing was already out while I was still disassembling the rest of it.

did you clean your parts for the pictures or was it like that when you disassembled it? if it was that clean then you were probably low on grease while you were using it.
 
Bartman said:
I would be curious to hear how many springs ABW recommends. I had one with five and one with three which my IA friend said to add two more to when it was apart.
Click to expand...

I asked the salesperson at Airframes Alaska the 3 or 5 spring question. His reply was that they send the new ones out with five springs, but some pilots prefer three springs. I bet they get that question a lot. A study of the infinite truths of the innerweb leads me to believe that the lighter your tail and better your tailwheel rigging the less you need the extra friction. I am going back together with five springs. If my tailwheel is shimmy free and well behaved, I might try the three springs just to see if I can tell a difference. Airframes Alaska had great service, a better price, quick response, and went out of their way to make sure I was getting the right parts. I'd certainly recommend them.
 
thanks for the follow up Joe, it's always nice to know we have another resource to go to for good information.
 
Another small step complete, tailwheel installed. I had to fabricate the dowel pin. The Scott 4226 pin turned out to be 0.015 thinner and 0.010 shorter than my original. I suspect the dowel pin bore in my tailwheel had been drilled out to the full 1/4" at some point. Punching the new dowel and the original with auto pin punch they seemed to be closer in hardness to mild steel than any of the hard bolts I compared to, so I fabricated the pin out of smooth rod. To square it up and adjust the length I chucked the dowel in a drill and held the spinning drill as square as I could against my spinning bench grinder. It took two tries but I came up with a dowel that looked as professional as the factory part and perfect on the length. Operates so much smoother now and the new tail spring has me back to a favorable castor angle. IMG_20220606_154637_HDR.webpIMG_20220606_154623_HDR.webpIMG_20220606_144436_HDR.webp I'm anxious to move the fuselage back out to the hanger and bring the wings into the shop.
 
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