Citabria Main Gear Swap

Forgot to mention @Bob Turner for the donor gear legs! Jim up at North Sound Aviation reconditioned them and a local body shop painted them so they're as good as new now.
 
Good stuff, can't wait to see the results.

How much trouble did you have getting the through bolts out? I had a terrible time of it, but I was poorly prepared with the wrong tools. I think a selection of stout pry bars would be most useful.
 
Do you mean the two AN-7 bolts at the inner end? You have to relieve the tension - wiggle the gear leg a bit. Maybe take the outer bolts off first, but do not allow the gear leg to fall and bend the inner bolt.
 
Bob Turner said:
Do you mean the two AN-7 bolts at the inner end? You have to relieve the tension - wiggle the gear leg a bit. Maybe take the outer bolts off first, but do not allow the gear leg to fall and bend the inner bolt.
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I did all that, but the bolts were seized up pretty tight in the gear leg holes, and there was no room above the bolt end to get any kind of leverage on it.
 
One of mine was bent. I suppose I could have bent it with the gear leg leverage. It has been maybe 8 years, but I think I tapped them out from the bottom.
As Bart says - they are his now. All renewed.
 
Here is a look at the issue I had. This is putting the new bolt back in, but it does illustrate the spatial challenge. Note the bolt is pointed upwards. Right now the bolt is about a half inch out. When it is fully inserted, the bolt end has less than 1/2 inch clearance with the frame member above it. It was tricky to finagle the box end wrench over the nut.

The challenge I had is that my bolts were seized tightly in the gear leg holes. There is very little clearance between the bolt and the bolt hole, and the hole was painted. Because of the tight quarters and the fact that the end of the gear leg was loose, it was hard to apply enough force to move the gear leg and bolt in opposite directions. Tapping the bolt out was not an option.

I did not anticipate the bolt being seized, so I did not bring appropriate tools, and I did not want to quit once I got started. I wound up pounding a chisel into the gap between the bolt head and gear leg. Trashed both pretty good, but that was fine because both were being replaced.

In retrospect, I should have clamped the gear leg firmly to the square member above it, and then used a pry bar on the end of the bolt and/or between the bolt head and gear leg.
PXL_20210306_200807040 (2).webp
 
A small collection of old and mismatched combination wrenches went to the hangar with me in case i needed one to grind to fit. Fortunately, I had an old Craftsman 9/16 box wrench that fit over the nut up top (12 point nut) and they both came loose using the wrench-on-the-end-of-a-wrench trick for extra torque. Had to cut two holes in the fabric to get lined up with the bolt heads and to be able to slide them out but once I had access, they both turned in place ok. we didn't remove the outer hardware, just loosened it, and leaving it in place gave a fulcrum to rock the gear leg up and down. With the nut in place flush at the top of the threads we used wood shims between the nut and the gear truss to work the bolt out by raising and lowering the outer end of the gear leg. lift the leg, insert more shims, push down, bolt moves out. one side was easier than the other and a pry bar with more wood shims made the difference.
we reused all of the hardware, it came out looking clean and went back in with a fresh coating of anti-seize.
 
Bartman said:
A small collection of old and mismatched combination wrenches went to the hangar with me in case i needed one to grind to fit. Fortunately, I had an old Craftsman 9/16 box wrench that fit over the nut up top (12 point nut) and they both came loose using the wrench-on-the-end-of-a-wrench trick for extra torque. Had to cut two holes in the fabric to get lined up with the bolt heads and to be able to slide them out but once I had access, they both turned in place ok. we didn't remove the outer hardware, just loosened it, and leaving it in place gave a fulcrum to rock the gear leg up and down. With the nut in place flush at the top of the threads we used wood shims between the nut and the gear truss to work the bolt out by raising and lowering the outer end of the gear leg. lift the leg, insert more shims, push down, bolt moves out. one side was easier than the other and a pry bar with more wood shims made the difference.
we reused all of the hardware, it came out looking clean and went back in with a fresh coating of anti-seize.
Click to expand...

You did a much better job than me ... I totally destroyed my bolts trying to remove them. Took the better part of a day.
 
Ed, I remembered your experience a few months ago and was ready for war but when the nuts were loosened and I was able to turn the bolts in place, it looked like it was my lucky day and things were going to move along. A friend of mine was helping and I was telling him about the bolts being stuck in the frame or the gear legs and how lucky we were that they were turning and sliding out.
 
Howdy,

Question about the gear mounting bolts:

Can the 2 outer bolts be tapped down from the top from inside the fuselage If they are corroded in place? It looks like I have to remove my 2 outer landing gear bolts on each gear to put mounting tabs for winter Ski cables and bungee's. I have original spring steel gear.

I have not opened up my belly as of yet, so just getting my ducks in a row so this procedure goes easy, or at least I won't get into to much trouble. I will be buying 4 new bolts which are a little longer anyway.

Any suggestions?

Ken "COWBOY" Winiarski
Cowboys Air RANCH (84ME)
 
The outer bolts go up into the frame and the nuts are accessible on top in the cabin, maybe under the upholstery but accessible. I'm not sure there's an engineering argument for installing the bolts up into the mounts vs. down but I'm pretty sure they're all mounted up so maybe there is actually a reason for that. You should be able to tap them down though from inside the cabin without too much difficulty. If you think they're corroded, get the nuts off and spend a couple of days dribbling WD-40 or something on the bolts so maybe they'll break free more easily.

Be careful to keep the fuselage from shifting in place once the bolts are out, they're the only thing maintaining the alignment of the gear legs fore/aft.

Good luck!
 
Cowboys Air Ranch 84ME said:
Howdy,

Question about the gear mounting bolts:

Can the 2 outer bolts be tapped down from the top from inside the fuselage If they are corroded in place? It looks like I have to remove my 2 outer landing gear bolts on each gear to put mounting tabs for winter Ski cables and bungee's. I have original spring steel gear.
Click to expand...
Yes, access is not an issue with the outer bolts. You'll have to peel back the interior side panels just a bit, but nothing traumatic. No problem thwacking the bolt ends, but I doubt you will need to.

You will need a 12 point box wrench or 12 point socket in the correct size for the nut. A six point socket will not work. You will also need a hex key socket in the correct size for the bolt head. I forget the sizes, sorry.
 
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