The International Cessna 170 Association

Any guesses to where this washer goes? Four are required. Cessna wants $23 a piece for them. You'd think gold but quite sure it's made from brass. I haven't found any at a reasonable price so It looks like I'll have to make them.

Funny how we think different. I did not even look at the dimensions, at least enough to correlate it to an AN-7 bolt. My eye instead was drawn to the left inner edge area flattened and thinned like it was made that way. Then I couldn't get past the crack on the right. Brass you say? Or is that bad lighting intentionally used to bring out the previously mentioned flaws and draw the experts thinking away from reality?

Gary has been places I haven't been in a 170. But there are more than one (or 4 of the same) expensive washer on a 170 when you include the engine. Ever price a few of them?. Bet more than a few Ace hardware washers lurk about doing their best to blend in as a Continental part number.

I've got no clue.

Gary,
Are the washers really only .035 thick? If they are they must be shims for something.

I recall seeing brass washers, like the one pictured, for the engine sump plugs. Mechanic thought they were original to engine and replaced them with "newer" crush washers.

n2582d wrote:Any guesses to where this washer goes? Four are required. Cessna wants $23 a piece for them. You'd think gold but quite sure it's made from brass. I haven't found any at a reasonable price so It looks like I'll have to make them.

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Since you received a price, I'm guessing you gave them a part number? If so, what is is?

Josh sounds like you're stumped
I'm now classified as an low level expert because I'm easily stumped.
An accessory part would be my inclination.

johneeb wrote:Gary,
Are the washers really only .035 thick? If they are they must be shims for something.

Now there's an engineer! I would never have made that connection. In fact, if you look online almost all brass washers are .062" thick. The p/n is 0522629 which has been superseded to S1450-7B12-032. It fits inside the wing -- under the aileron and flap bellcranks--between the bellcranks and the wing. The bellcranks, with a top and bottom needle bearing, are free to slide vertically on their respective bushing shafts. The shim washer's purpose is to keep the steel bellcrank's shaft from rubbing a "donut" in the lower wing. These center bushings are 3/8" diameter and around .060" longer than the bellcrank tubes. So this washer could be slightly thicker and also could have an ID closer to 3/8" than 7/16".

Some engineer, I the guy who now has to go to his airplane and make sure he put those washers back in when he re-assembled his wings.

Yeah, just looking at the illustration one would think they are showing an AN960 washer to go under the nut. Maybe we can get Bruce to CNC us a couple of these brass shim washers!

John, you'd do well to disregard all my posts as your plane would be in a thousand pieces before long! For example, I've been looking at all my bearings in the flight control systems -- aileron, elevator, rudder, trim, and flaps. Most are frozen or, at best, hard to turn. I doubt my plane is unique in this regard. Without disassembling the part and physically looking at the bearing it is very difficult to determine if the bearing is rolling or if it is working as a bushing.

I took the flap drive system out of a Cessna XP about a year ago (the washer in that case was much thinner), it was just a horrible job as the through bolt had seized on the bearings. The quadrant still worked fine as the bearings themselves were not seized, but to remove the quadrant I had to drill off the head and shank below the surface of the wing skins and doubler under the wing skin.
So....if your quadrant is rotating just fine but you want to put in a new washer, I'd check whether the bolt moves first before diving in.

Wrong again; .035 it is

Jim the ex-pert. We just have to figure out what the acronym pert stands for. Probably top secret Canadian TCAA stuff.

Wow, when I had mine apart [some time ago during the SIDS inspection] the "brass" thrust washer was plastic . It had wear marks from the tubes movement and I turned them around . I never thought it would be anything else . They were not worn enough for replacement . Not the easiest component to refit.

c170b53 wrote:I took the flap drive system out of a Cessna XP about a year ago (the washer in that case was much thinner), it was just a horrible job as the through bolt had seized on the bearings. ...

Just to be clear Jim, you mean the through bolt had rusted to the bushing - the long hollow tube - correct? It's interesting that the ID of your washer looks smaller than mine. It looks to me that it is designed to fit under, rather than around, the 3/8" dia. bushing. Is the p/n of the washer the same for the XP? Could be my washer is not the correct ID???

I picked up a scrap early 172 wing from Faeth Aircraft for $30 to harvest some ribs for my wing rebuild. Since I had a 172 flap belcrank I practiced brazing a nut to the shaft to attach a zerk fitting to. Trying to figure out a way to better lubricate the bearings on either end of these bellcrank shafts. I think the ideal solution would be to find some sealed bearings.

The bolt was seized solid on the bushing p/n 0523536. Could'nt even drive it out on the bench. Bushing is the same but p/n for the flap quadrant washer is different, good eye Gary.
The 79 Xp IPC lists the washer as s1450-20B12-032 for the flap quadrant
The aileron washer is 0522629-1 .
A true expect could figure out how Cessna numbers their parts
Bruce I on the other hand, like to consider myself more as the absent minded mechanic (professor) rather than expert.
Seeing as I had forgotten all about this, I obviously ..NAILED IT...