upgrading to lady legs

cpolsley · Post by **cpolsley** » Sat Jan 13, 2007 12:41 am

I have removed the early style gear legs and in the process of installing the lady legs. The lady legs are thicker than the early style gear legs and I have two issues. 1. Due to the thicker legs, the shims and wedges together, will not fit between the casting and the top of the gear leg. The parts manual indicates the shims are AR (as required) so one would assume you can put the wedges in without any shims. Any feed back on the first issue?
2. The wedges alone will go through the gap and tighten up. However, the wedges when seated (bolts tight) leave about a
1/2" gap between the face of the casting and the wedge adustment bolt area of the wedge. Is that gap going to allow the wedge bolt to flex, although slightly, when the gear is flexing? Should I machine the wedges to allow them to slide in a little more or not worry about it. With the other gear the wedges along with the shims adjusted up almost right against the gear box casting.

blueldr · Post by **blueldr** » Sat Jan 13, 2007 5:07 am

When I installed the Lady Legs on my '52, I ground the wedges down so that they almost seated under the bolts. I neever had any loosening or other ptoblems with them and would do the same thing again.

hilltop170 · Post by **hilltop170** » Sat Jan 13, 2007 5:57 am

If you do grind the wedges down some, remember they only work as wedges as long as there IS a gap between them and and the gear box casting. My opinion is 1/2" is not too much of a gap anyway as long as the bolts have proper engagement, they might take-up a little more once the gear seats-in and then you'll need some extra gap. The shims aren't required, only if you need them. I always put a good coat of zinc chromate paste on the wedges to help guard against dissimilar metal corrosion between the steel wedges and aluminum casting. Probably overkill but I've never had any corrosion either.

Romeo Tango · Post by **Romeo Tango** » Sat Jan 13, 2007 8:07 am

Gear legs are good, great and amazing. But the best thing you can do is add the PPonk stiffeners. I know this is a lightning rod, but having watched them installed, I am happy to land on the harshest of terrain. I put a multi-ton lateral shear-load in Lancaster a few months ago and had zero concern about losing the gear (I had plenty of concern about losing my lunch, being pushed inexorably toward the landing lights on the left side).

Bottom line - I am happy to land at long as the upwind wingtip is not touching the ground.

cpolsley · Post by **cpolsley** » Sat Jan 13, 2007 12:15 pm

Romeo Tango, I have the ponk kit in hand ready to put on but I want the get all the alignment set up first. When I removed the gear legs I found no corrosion on the gear box casting, I was a little concerned about that having read other accounts. The only thing I did was replace about four loose rivets which I had known about. These were located under the gear leg, the first row of rivets under the leg which you can see form outside going through the lower fuselage skin into the bottom portion of the outer casting. The airplane sit outside a good many of its 53 years and I would assume it was from the wind rocking it most its life.

Thanks for the feedback, I did grind a little off the wedges but I think I will take off a little more so they fit to within about a 1/4".

lowNslow · Post by **lowNslow** » Sat Jan 13, 2007 5:43 pm

Here is some info from pponks old web site that may be useful. Also if you bought a pponk mod from Steve Knopp, don't hesitate to give them a call for some advice.

Steps to Installation

1) Hoist the airplane.

2) Install your gear in the aft position. This should leave you 1/16th to 3/32nds inch gap between the gear and the front of the bracket. If the gap is larger than this, check the rear portion of the bracket that touches the landing gear to see if it has compression damage due to years of use and striking objects with the landing gear. (Inspect for stress fractures and cracks in any compressed areas.) A symptom of "too large a gap" is a chronic "clunk" when you land or take off. Tightening the shims is only a temporary fix for the problem...the "clunk" usually comes back.

3) Install the wedges and shims so that they do not push all the way in and bottom out. If they bottom out, install an extra shim. (Parts Manual allows more than one shim. You also may need a thicker wedge.) There are 2 sets of shims and wedges holding each set of gear in place.

4) Tap the forward wedge lightly with an aluminum punch and hammer to set the wedge. Screw your 1/4" bolt up snug to the wedge.

5) Repeat this procedure for the rear wedge.

6) Tap the forward wedge again lightly with a punch and hammer to reset the wedge, and again snug up the 1/4" bolt.

7) Repeat this procedure for the rear wedge.

Note: Do not over tighten this bolt...it is there only to keep the wedge from backing out. DO NOT POUND IN THESE WEDGES, THINKING YOU WILL KEEP THE GEAR FROM MOVING. You only will damage the outboard brackets (and keep me in business).

For those of you who are reading this, if you are interested in seeing how your landing gear is installed in your aircraft, go to our web site http://www.pponk.com and click on the picture of the outboard gear box bracket(it takes some time to load...just wait for it. It is worth it. This is an exploded view of the landing gear box.

Steve Knopp

cpolsley · Post by **cpolsley** » Sun Jan 14, 2007 3:33 pm

lowanslow thanks for the info from pponk re: gear installation and thanks to all, I think that answers all my questions.

The International Cessna 170 Association

upgrading to lady legs

upgrading to lady legs

The "rest of the story"