140 gear leg adjustment

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8422
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140 gear leg adjustment

Post by 8422 »

Anyone ever replace or install the gear leg in their restoration projects? I have found that in trying to level the wings that the attach point in the fuselage is with one bolt into the box and that there are two 3 inch angle wedge like brackets that fit between the top surface of the leg and the box.
The problem is one wing is lower than the other, 3-4 inches lower. I replaced the gear leg with another that came with the plane some years back and now after replacing it that wing is higher than the opposite. I'm wondering if these wedges acts as shims that can be adjusted thus making the fuselage tilt with the mis-adjustment of the gear. Finding that the lower wing has worn the tire on one side quicker than the other.
In looking through the service manual (IPB) there is nothing about adjustment of the gear legs.
Any experience you might have I would like to hear about it.

Thanks
DMc
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Re: 140 gear leg adjustment

Post by 1125 »

I rebuilt my 120 after wind damage a number of years ago. Jacked up the fuselage, removed the gear to check the gear box area for any cracks and inspect for corrosion, damage, etc. I happen to have a 1946 with 1948 landing gear (no mention in the logbook how it got there). We did all the cleaning, inspection, reassembly and all was well. We measured the height at the wing root and it was the same on each side with the wings off, flat surface, etc. (Not sure if that was correct or not, just did it to see if all looked correct). If you are wearing the tires on the outside or inside, there is info on the website and the tech manual how to correct. About the wings being higher or lower, you may have two different gear legs. There should be a number on each of them on the very inside edge somewhere, check that out and ask other folks who have rebuilt our aircraft. You may have two different gear legs. Good luck.
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Re: 140 gear leg adjustment

Post by 6643 »

You can raise or lower one side by adding (or removing) washers between the gear leg and gear box where the big honking bolt is. (Ref. Cessna 100 series manual par. 5-6). The tolerance is a 3" difference, measured, I assume, at the wing tips.

If you have early, straight legs, and have 3 of them, have you tried taking the one you removed from one side and putting it on the opposite side?
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Re: 140 gear leg adjustment

Post by 8422 »

The idea of washers under the bolt is an idea. It wouldn't take much at the gear to raise or lower the wing tip quite a bit. Thanks.
DMc
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Re: 140 gear leg adjustment

Post by 7133 »

I have a similar situation with one side sitting a little higher than the other. Just wondering how the washer between gear leg and gear box actually works in practice. Raising the gear leg on one side would lower the fuselage on that side, but I am thinking it would then steepen the gear leg angle, which would raise the fuselage. If you have done this, I would really like to know the outcome.
Cheers
Michael
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Re: 140 gear leg adjustment

Post by 6643 »

The washers (shims) go under the inboard end of the spring. The outside edge of the gear box acts as a fulcrum. Adding shims reduces the angle of the spring and raises the wing tip. The difference between the height of the two wing tips should not exceed 3 inches.
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Re: 140 gear leg adjustment

Post by 7133 »

Makes sense.
Thank you
Michael
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Re: 140 gear leg adjustment

Post by 6673 »

I’m installing my landing gear after a repair. Having a real hard time getting the shims (wedges) to seat properly. Is their a better technique than using a punch and a hammer?

Thank you in advance!

Nick
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Re: 140 gear leg adjustment

Post by 7133 »

Wondering what the best way is to lift the fuselage. Jacking up, or lifting from above?
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Re: 140 gear leg adjustment

Post by 8342 »

7133 wrote: Fri Oct 08, 2021 5:48 pm Wondering what the best way is to lift the fuselage. Jacking up, or lifting from above?
It depends.
What are you wanting to do?
Here is what the Pilots Operating Haandbook says:

LIFTNG AND JACKING:
The airplane may be lifted by an appropriate sling at the engine mount fuselage attachment fitting or by lifting lugs on the engine and a sling around the aft section of the fuselage.


Rick
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