I just had a trim wheel roll pin failure while attempting to trim for cruise. Landed uneventfully...and replaced the 2 sheared pins(one for wheel to shaft and other from shaft to sprocket). While replacing the roll pins i noticed the shaft to have egged out holes. OK, so shaft no problem, Mcfarlane sells it. While i was searching the shaft i found new sprockets available. But in the catalog it doesnt list the proper sprocket with part number. MC0761210-1 is what i would believe to be correct. After calling mcfarlane they couldnt offer any advice. my question is regarding the interchangeability of this part number. will this sprocket work on my airframe (LATE MODEL 1979)? while im in there doing the shaft id like to replace the sprocket.

any help from the group would be appreciated.

thanks in advance, Brandon

I don’t have a direct answer to your question, but the machined aluminum trim wheel that McFarlane just acquired from QMI is Worthy of consideration. It is a VERY nice upgrade that takes the stress out of the roll pins.

https://www.mcfarlaneaviation.com/articles/new-trim-wheel-kit/

A pal has one installed on his wagon. It’s super neat. This is high on my list of airframe improvements.

It really is a nicely done kit! I do ultimately plan to do a similar setup. Read somewhere that Cessna did this on later models. I’ll be using my Cessna trim wheel, the new sprocket and a spacer all thru drilled and assembled to one piece. Looking forward to eliminating the roll pins from the load.

had the same thing on my 1975 A185F. They were able to determine that shaft was an acceptable replacement and no problem. The qmi looks nice but pricey. While I was at this I realized the trim cable tension was too low likely putting more stress on it and will cause it to fail again early. Feels better after set to 23 pounds. There should be a mechanic on here that can chime in.

L16Driver wrote:It really is a nicely done kit! I do ultimately plan to do a similar setup. Read somewhere that Cessna did this on later models. I’ll be using my Cessna trim wheel, the new sprocket and a spacer all thru drilled and assembled to one piece. Looking forward to eliminating the roll pins from the load.

There was a thread here about this a while back, as well as a thread on the supercub site.
Here's a couple pics from those threads:

Thanks for sharing the pics!

How are your jack screws? When I bought my 185 in January the trim wheel was super stiff. While messing with it in the hangar lubing it and trying to make it work better I sheared off a pin.

With McFarlanes new jackscrew kit it trims with practically no effort.

Won’t fix your egged out roll pin holes but might be the cause of.

Scolopax wrote:I don’t have a direct answer to your question, but the machined aluminum trim wheel that McFarlane just acquired from QMI is Worthy of consideration. It is a VERY nice upgrade that takes the stress out of the roll pins.

https://www.mcfarlaneaviation.com/articles/new-trim-wheel-kit/

A pal has one installed on his wagon. It’s super neat. This is high on my list of airframe improvements.

It is very nice indeed, but it might be worth pointing out that this kit is $2K.