The International Cessna 170 Association

Hello all! I noticed today that I have a crack in my spinner and I am looking to replace it with a new or used one. I have O-300D with the 6 bolt crank and I am trying to figure where to find a bullet spinner without the forward bulkhead. Any insights or leads on a new/used dome would be very much appreciated![/img]

So, I’m guessing you have a custom-built 6-bolt back-plate..?

Hi George,

That is what I am finding out. It looks like someone modified a bullet spinner to work with the 6 bolt crank. It has the 6 bolt backplate and the forward flange that is held on with the prop bolts. There is a guy that is relatively close to me that can weld it and return it to service with a yellow tag which I was very happy to learn.

That’ll be a magical yellow tag if it’s possible. The FAA has always condemned welded spinners in the past. (Although it was done by an Certified Aircraft Welder to my Baron spinner and it’s now been 29 years and that spinner is still spinnin’ on that Baron.)

Wyoflyboy…do you have a pic? I’m trying to imagine what you’re describing. The original spinner did not have a fwd bulkhead IIRC… …the front plate was actually attached to the Dome already….and was originally for 170B. (altbough there was a later “pointy” dome for 172s and it was made for the 6-bolt prop.)

Here’s a pic of the Spruce Catalog page:

The shop that I found is a certified shop that is able to weld repair spinners. I guess he is one of two shops in the country that are able to legally do that sort of work.

I wish I took pictures of the dome, but here is the forward bulkhead.

Just received a spinner back from a CRS with 8130 after weld repair.....

That looks like a later 172 spinner backplate and front plate…(what spruce sells for 172 A-F models).

Shouldn't the prop bolts be safety wired?

The C-172 A,B,C models (SNs 46755 thru 49544) utilized AN8-4A bolts (undrilled) for the prop/spinner which were threaded into MS20365-820C self-locking nuts. Note the spinner assembly for those SNs. (The C170B actually used a different spinner with the original 8-bolt prop…the dome of-which was a “less-pointy” or “blunt” appearance….and which had the front plate “integral”. Some owners who installed the early “blunt” appearing spinner found it necessary to custom-fabricate a 6-bolt back-plate. The difference in appearance is minor….but noticeable once it’s been pointed-out. (pardon the point) See the bottom pic for comparison.