About 10 years ago or more I replaced the Maule tailwheel with an Alaska Bushwheel 3200 (3224A). I own a 1994 Mx-180. During the last tire change, which we do about every two years it seems, the entire tailwheel was lose. The mechanic removed the bolt and the washer was concave with an imprint of the nut in the washer. The mechanic is at a loss for what is wrong. Does this tailwheel need a leaf spring adapter? There was no adapter on it. What size bolt holds the tailwheel on?

This has been common on the 2 planes I've owned with 3200 tailwheels. There are two bolt sizes available, AN7 with bushing or AN8. I prefer the 8 as you can achieve more torque which means more axial load.

The legal solution is a properly torqued AN365 or AN363 (all metal) nut over an AN960 washer, likely what you had. Check torque regularly. Can't see that it's loose until the weight is off the tailwheel. If flying on rough surfaces, should be part of every preflight in my experience. Crazy how fast it can loosen. The AN363's seem to stay tighter longer. A hardened washer does not cave in and keeps it tighter longer, but can be hard to find. Still inspect very regularly.

A setup that works way better and does not loosen, ever, is a hardened washer and an AN310 castle nut fully torqued down with a cotter pin. This is not a legal/correct installation theoretically but "they say" it works great.

This also happened on the forward tailwheel spring-to-fuselage on my scout regularly but I did not see that happening on my M7.

Is there an leaf spring adapter required?

Mauleflyer wrote: ↑

Fri Feb 10, 2023 9:55 am

Is there an leaf spring adapter required?

Is your leaf spring narrower than the saddle cut out on the tailwheel head? If so, then yes. My ABI tailwheel head matches the leaf spring width. ABI makes adapters for 1.25" and 1.5" tailwheel springs.

Yes, as ASA said if you have the 1 1/4" gray tail spring then you need an adapter. If you have the Black ABI 1 1/2" tail spring no adapter needed, and I think the AN8 1/2" dia bolt works best and one needs to replace all the bolts at a regular interval as I have the forward AN6 bolt lock nuts loosen and one failed and jammed to rudder and ended up leading to a ground loop. And the Maule gray tail spring will hold its arc angle much longer that the ABI tail spring ever will.