The International Cessna 170 Association

Hello everyone, I just got my 1949 C-170A back from an annual inspection. I let the mechanic know before the inspection I had a concern about the plane not sitting level. The mechanic told me I have a sprung gear leg. I thought the one leg looked a little off. I have the P Ponk kit installed, is there a way to correct this or do I need a new gear leg? I know P Ponk offers shims but would that be the fix? And if I need a new gear leg, can I get just one or do you need to buy a set?

Thanks, Don

Don,
Cessna says that if your gear is bent your only option is to replace it. But I would talk with Jim Hayton of North Sound Aviation (360) 661-3302 or Tom Anderson at the The Landing Gear Works about your options. Be wary of getting a replacement leg online. For example, here is a leg currently offered on eBay for a great price: https://www.ebay.com/itm/225485334296. First, it is incorrectly identified as an early C-170 gear, p/n 0541114. The two holes mid-gear indicate that it is for a C-120/140. The holes are for mounting the step on these aircraft. Second, you don't know if the paint has been removed with a paint stripper. Doing so with many paint strippers will cause hydrogen embrittlement. Finally, it would be very hard to tell by the pictures whether this gear is also bent or not.

Regarding the shims, I don't know which shims P.Ponk offers. The wedge shims for the outboard gear mount (p/n 0741007, fig.26-6), do nothing for raising a low wing. The shim at the inboard end, (p/n 0541105, fig. 26-10), is used to level the wings. If your P.Ponk reinforcements have not been installed to allow for these shims they will have to be removed and milled to install shims. The C-185 uses the same inboard shims as the C-170. According to the C-185 Service Manual a maximum of three of these shims are allowed. The shims are 0.065" thick so 0.195" would be the maximum allowable shim thickness if one were to use the three shim limitation of the C-185 Service Manual. You would not need to buy a new set of gear; only need to replace the bent one. The later style gear, known as the lady-leg gear, has a specific part number for the left and right side. The early style gear -- which was original to your C-170A -- is interchangeable between left and right -- p/n 0541114.

I don't have the PPonk kit installed but Mountain Airframe was able to correct a 6-inch wing-low condition on my B-model with AN washers under the gear attach bolt.

n2582d wrote:First, it is incorrectly identified as an early C-170 gear, p/n 0541114. The two holes mid-gear indicate that it is for a C-120/140.

170 and 170A serials 18001 to 19219 had drilled gear. A screw is what held the brake line holder to the leg. The next iteration of the gear the hole became a dimple only but otherwise unchanged from the earlier gear. Lady Legs started with serial 25612.

The problem with that ebay gear is two holes. 170 gear only had one.

Don,
Five years ago Duane Shockey wrote this:

DuaneShockey wrote:I have a 48 ragwing since 1976. It had gear legs with the hole drilled through each to fasten the clamp for the brake line. I was told long ago that they were known to have failed many times over the years for 48's. I heeded the warning and bought some "A" legs from John Benham. They are stiffer and they don't bend as much in a tight turn on the ground causing a squat as the originals did. They are in my hangar if anybody wants them. Duane Shockey

Might be worth checking if they’re still available.

I recently replaced the stock gear on my '51 170A with 180 gear legs. They were/are in serviceable condition as far as I know. If someone needs a set, don't be shy to reach out. I'm willing to offer a decent deal for a fellow member.

I don’t have anything of “valid” interest to contribute….but while reading thru this thread…it occurred to me that we’ve been missing-out on yet-another convoluted discussion we could have had…. regarding: “Is it possible…or appropriate…to MIX an early gear leg equipped airplane…with a later “lady” gear-leg …on the same airframe? For example, an early gear-leg B-model (pre: 25612) needing only one leg replaced… Would it be appropriate and legal to install a later lady-leg on one side of the airplane while retaining the early leg on the opposite side?

This just screams for a nice, new controversy. LOL.

I wouldn’t do it. I wouldn’t recommend it. But it just now popped-up in my twisted-mind that this is the sort of question that could provoke endless arguments we’ve been Missing-Out ON!

George, an airframe with mixed gear as you suggest would look strange enough I'd have to wonder who would think it correct and fly the airplane. I'd think the different bending rate of each gear would make it a real hand full on anything but a glass smooth landing.

Bruce, I’m certainly in agreement with you… but as nutty as some things which have come-up here… I’m surprised someone hasn’t presented it by now.
The curious thing about it …. at least on paper…. is legality. Offhand… I’m not immediately struck by any prohibition other than sensibility and judgement.

I have another question. If the the pilot side gear leg is sprung, would this cause the plane to pull to the left on takeoff on pavement? I don't notice it very much on grass but its a bit of a hand full on the pavement. It starts to happen right as the plane is starting to develop lift. Would the plane not siting level cause this?

Thanks, Don

Dferr34 wrote:I have another question. If the the pilot side gear leg is sprung, would this cause the plane to pull to the left on takeoff on pavement? I don't notice it very much on grass but its a bit of a hand full on the pavement. It starts to happen right as the plane is starting to develop lift. Would the plane not siting level cause this?

Thanks, Don

Don, if you could email a picture or two from various angles of your landing gear and airplane I might be able to post them here and we’d all be better equipped to assist you. It may be that your wheels simply need alignment….and that is a less expensive/less extensive procedure.

Okay, thanks. I'll see if I can get some good pics.

Thanks!

How do I add pictures?

Membership in the Assoc’n is req’d to upload pics…. but you can click on my username and email them to me and I’ll add them.