limerick wrote:

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WOW, your job looks excellent Limerick, could not be better! Congrats!

Was your aircraft not front cover of an AOPA magazine some years back with an article of it??

Thanks Manuel. Yes, February 2014. I wish you much success in your MLG bracket replacement project.

If able post a few pictures.

Bruce

limerick wrote:Thanks Manuel. Yes, February 2014. I wish you much success in your MLG bracket replacement project.

If able post a few pictures.

Bruce

Thanks Bruce, what a coincidence, I came across that article just recently.
Congrats.

https://www.aopa.org/news-and-media/all ... 0-skywagon

Brgds.

My only intent is sharing this is getting good info out there. I have no problem being wrong if I get to learn something.

I have a friend who is a pretty good sheet metal guy. He saw this thread and sent my these pics of an airplane he is rebuilding a gear box on right now. The story is the outer brackets were replaced out the top. I have no idea how "carefully" the angles were bent but 5 years later cracks were found in them so the repair you see below was installed. That lasted 6 years until a "firm" landing (not sure how you qualify firm to hard landing) when the forward gearbox on the LH side failed as shown in the 3rd pic.





It truly isn't terribly difficult to get it out the bottom and return the structure to exactly the way it was when Cessna pushed it out in to the world.

Some people talk about a supposed SB (?) to do it from top cutting those angles sort of what you show on the first two pics AEROPOD, anyone knows if that document really exists??

Any chance for a wider view of the 3rd Pic Aeropod?

I have enjoyed following, thanks to all the posters, Tony I love how you use crutches. I have replaced several of the cracked angles which attach to the belly skin and the outer gear bracket. This was done with fabricated hammers and back riveting through the landing gear slot. The factory heads were bucked with a fabricated jack screw bucking device going through the floor board inspection hole.

bush master wrote:I have enjoyed following, thanks to all the posters, Tony I love how you use crutches. I have replaced several of the cracked angles which attach to the belly skin and the outer gear bracket. This was done with fabricated hammers and back riveting through the landing gear slot. The factory heads were bucked with a fabricated jack screw bucking device going through the floor board inspection hole.

Any Pics. you can share about that Bush Master?

[email protected] wrote:Some people talk about a supposed SB (?) to do it from top cutting those angles sort of what you show on the first two pics AEROPOD, anyone knows if that document really exists??

Any chance for a wider view of the 3rd Pic Aeropod?

Never heard of a service bulletin for that, but I could be wrong. I keep finding more old service letters and bulletins that I'd never heard of the longer I do this. The support from Cessna is awesome some days and difficult others.

My buddy thought he might still have that old bulkhead in the scrap heap, waiting to hear back so I can share better pics.

Here are some pics of half of a scrap gear box I have from a wreck. I keep this around just for show and tell.

Notice how the angle that was bent by Limerick and others is actually the bulkhead itself. I could see bending it up for the job and then back down IF you could add a doubler that was long enough to go a long ways inboard. The problem is that the inner bracket doesn't allow for it.

bush master wrote:I have enjoyed following, thanks to all the posters, Tony I love how you use crutches. I have replaced several of the cracked angles which attach to the belly skin and the outer gear bracket. This was done with fabricated hammers and back riveting through the landing gear slot. The factory heads were bucked with a fabricated jack screw bucking device going through the floor board inspection hole.

The crutches were a joke I sent those to the customer in the middle of the project. I added the second crutch and asked if he wanted bushwheels.

I see that angle cracked regularly. Sometimes it is hard to see the cracks because of accumulated dirt/grime. You have to remove the gear leg and scrub that out so you can get a good look at it. I also see the rivets that attach that angle to the bracket sheared regularly. The head will look fine from the outside but the bucktail is MIA inside. I am comfortable replacing a sheared rivet with a #8 screw, washer, and nut as long as it is torqued properly. Just know you'll probably be back in there soon to replace the angle. The other problem with this is you have to over size the hole for a screw, so if you want to replace the angle down the road, you have to use a screw, can't use a rivet because you drilled it too big.

NEVER reuse those angles. Just make new ones. It's a shame to do all this work and have to go back in to replace that angle in 100 hours.

I'd like to see those tools!

Tony, Kent has the tools and maybe pictures, give him a call. Kent Orr A1 Aircraft 308-390-5974

bush master wrote:Tony, Kent has the tools and maybe pictures, give him a call. Kent Orr A1 Aircraft 308-390-5974

I know Kent!

I've been contacted by a few guys concerning how to do this and I've spent some time walking them through it on the phone. I promised them some pics of what exactly needs to get drilled out. I figured these may be useful to folks down the road if they are archived here. In addition to what is shown below, you'll need to remove the floor section between the rudder pedals and the gear box.

All of the rivets to the below of this line will be drilled out. If you have an early airplane it may not have the trapezoidal doubler. You'll still need to drill out that row of rivets at the top and remove the fuel step if you have one so you can get the floor out inside. Note the 2 cherry rivets at the front of the engine mount stringer. Those are the only 2 cherries that I install. There is a way around that if you want, but I just feel like the juice isn't worth the squeeze.



All the rivets to the right up to the line depicted in the picture above need to come out.


Same deal on the inside of this line. There are some rivets that are shadowed by the strut. If you've made it this far, you'll be able to sort that out.


You need to be SUPER-CAREFUL drilling all of these out. You don't want to oval any of the holes or you'll need to go up a size in rivets. The early 180s have a lot of 426 countersunk rivets in the boot cowl area which is cool for looks, but sucks for durability. Be careful so you don't end up with smoking rivets in a couple hundred hours.

Holler if you have questions.

AEROPOD wrote: I've been contacted by a few guys concerning how to do this and I've spent some time walking them through it on the phone. I promised them some pics of what exactly needs to get drilled out. I figured these may be useful to folks down the road if they are archived here......

Holy smoke, that's a LOT of rivets!
Thanks for posting the pics & detailed narrative here.
Luckily I am not contemplating this repair,
but I'm always interested in learning more about working on these airplanes.

Replaced my right outer gear leg casting in October 04 .got part from Steve knopp he told me how to change it out the top.had no problems never bent anything. Took me 16 hrs looks original that was over. 2000 hrs .nothing lose yet . Did all my self needed a hand to buck 2 rivets

Just for the record- there a lot of these airplanes that have had these brackets changed through the top and gone on to lead long happy lives. Thanks to Aeropod for the pics and description; that’s probably the “very best practices” way to do it and keep it 100% stock and not modify any structure at all. But like a lot of things, there can be more than one way to do it “right”. There are extremely well respected life long mechanics in Alaska that have changed tons of these things from the top- it’s a widely accepted practice. Does that make them “cobs”? Ask the 135 operators who’ve gone on to put thousands of hours on those airplanes after the repair…

Hello Cub180 and Flyer.

Truely appreciate your posts on this interesting discussion.

Have also been told it can be safely done from the top.
Any chance for you to share the procedure here or via WA +50252086821 pls? (Guatemala) You can call any time.
My email [email protected]

Thx again.

Just finished the 1785th call checking with readers...

All said the same, " I ain't sleeping till any of those two guys share the secret"

Amen ak49flyer!! -Bruce