C180 Gear - Which shims to use?

MeeksDigital · Post by **MeeksDigital** » Thu Dec 21, 2006 7:45 am

I recently bought a C170A with the C180 Gear/P.Ponk conversion on it. On the ground, both wheels/tires are angled inward, and a few people have mentioned that this might be a contributing factor to the touchiness on landing, and that I might want to shim the axles so that the tires rest somewhat more level on the ground.

I looked at A/C Spruce, and they have three different shims available. Can anyone suggest which angle shims to use on my plane?

Thanks a bunch!

Post by **GAHorn** » Thu Dec 21, 2006 7:48 am

Trevor, that's going to depend upon just how much you need to change the toe-in to toe-out. You'll need to measure your actual toe-in, then calculate which shims will nuetralize the wheels.
Ideally, at 2,000 lbs you'll have zero toe-in/out.

MeeksDigital · Post by **MeeksDigital** » Thu Dec 21, 2006 7:56 am

I figured it was a situation-specific answer... I'll measure that when I get home from my holiday family obligations

Thanks for the help!

Roesbery · Post by **Roesbery** » Thu Dec 21, 2006 8:16 pm

Assuming you have shims, you may be able to reposition them to get the needed correction.

MeeksDigital · Post by **MeeksDigital** » Thu Dec 21, 2006 9:18 pm

i guess what i'm looking at is the CAMBER, not the Toe-In. The wheels are not necessarily out of alignment, but the bottoms are angled inward, like, towards the belly of the airplane. I ordered a set of 1 degree shims from aircraft spruce today, but after looking into this further I think I'll need a few sets, since the camber is off probably around 3 degrees...

when I get home, I'll do a more accurate measurement.

Post by **GAHorn** » Fri Dec 22, 2006 4:20 am

Your camber should only zero out completely at 2000 lbs. If your airplane isn't loaded down, some positive camber is normal.

MeeksDigital · Post by **MeeksDigital** » Fri Dec 22, 2006 4:30 am

there seems to be quite a bit of positive camber, even when loaded. when I get home from this trip on saturday, i'm going to take some measurements and start installing shims.

thanks for the help guys!

blueldr · Post by **blueldr** » Fri Dec 22, 2006 5:41 am

Re: Wheel alignment, the maintenance manual outlines the proper procedure for checking and setting both camber and toe.

Improper alignment can make the airplane really squirrely on the ground.

MeeksDigital · Post by **MeeksDigital** » Fri Dec 22, 2006 5:42 am

it isnt the alignment thats particularly off... its the camber that concerns me. the airplane isn't overly sensitive on landing, its just a bit touchier than i have experienced on other 170s. we'll see...