#!?#!!#% Southcos! Replacement?

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Sundancer

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172M. Had it with the Southco cowl fasteners. Switch to Skybolt? Screws? Better ideas?
 
Sundancer said:
. Switch to Skybolt?
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Skybolt conversion kits are convenient but a bit pricey. Cheaper to buy separately or different mfg'r. Screws can be a pain after a period but have installed both. It can be a bit labor intensive especially if repairs are needed prior to conversion. Talk to your mechanic first to get his take. A couple times I had to get one of the sheetmetal guys from day job to fix cracks that were outside my skill set.
 
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The Southco quarter-turn fasteners are also called DZUS.
 
Domenick said:
The Southco quarter-turn fasteners are also called DZUS.
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Dzus is a completely different affair.

Dzus:
serveimage

The bolt has a spiral groove in it that grabs the spring wire.


Southco:

southco.jpg


Southcos use a small hammerhead cam and various types of receptacles, including Cessna's cowl shockmounts.

Southco might own Dzus, but the designs are completely different.
 
Yes, the Southcos are a pain, but I found the Skybolts to be just another type of pain. By the time I retired Skybolt was on their third or fourth generation of cowl shockmounts, as all the previous affairs were so troublesome. Part of the problem is their use of aluminum in some places where steel would be better. The aluminum plates would crack, the aluminum sockets would gall, and so on. And the Skybolts would work loose and wallow out their holes in the cowling, too, no better than Southcos.

They're based on the Camlock design, which is all-steel. Should have stuck with it.
 
Do you like Camlocs? I'm hearing mixed reviews elsewhere on Skybolt; some people think they've worked out the issues, some not so much. I'm just certain Southcos are not a starter. I can live with screws, but if the Skybolts will hold up for a reasonable length of time, the convenience is nice.

Aren't the new 172s using something other than Southcos?
 
Be careful what you wish for. The cowlings on my Mooney will never move. The ten million screws that hold them on ensure that. Good luck decowling the thing. Take some a half hour. Most days I take off without having a good look at the engine.
 
:) I got an informed estimate it takes a solid 15 minutes to remove all the screws on a 172 cowl secured in that manner. Looks like we'll go with Skybolts at annual.
 
Sundancer said:
:) I got an informed estimate it takes a solid 15 minutes to remove all the screws on a 172 cowl secured in that manner. Looks like we'll go with Skybolts at annual.
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Five minutes to remove, 15 to reinstall, on an old 172. Much worse when the tinnerman nuts are shot and people have been using progressively larger screws so that you have this wild assortment of sizes when you go to close things up and you have to figure out what size went where. You end up using larger screws in some iffy spots so that you have small screws left over and have to go get some more larger screws. An owner pays for that sort of time at every annual or oil change, and he'd save money in the long run if he just had the shop replace every nut and be done with it.

I don't think SKybolt has a kit for those old non-shockmount-cowl 172s. Edit: They do. https://store.skybolt.com/conversion-kits-c172c2800p-c347.aspx
 
I don't like southcos as much as the net guy but not enough to spend money to change it to a different headache.

All I did was
  • take tape and mark which are loose before removing cowls
  • replaced all worn ones
  • installed the cupped plastic washers under all of them
  • Throw away the retainers that hold the ones into the holes that fasten the top cowl to the bottom cowl, those come complete out every time I R&R the cowl.
  • Stabbed a carboard box with appropriate # of holes to organize the fasteners as I remove them, ensuring they end up in the same holes they came out of. I use this template box every time I R&R the cowl.
  • Keep extra plastic cupped washers and black flat washer and southcos of various length 110, 120, 130, 140 on hand to shim and or replace as necessary.
After fighting loose pins on camlocks and airlocks I don't think southcos are all that bad.
 
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Dan Thomas said:
Five minutes to remove, 15 to reinstall, on an old 172. Much worse when the tinnerman nuts are shot and people have been using progressively larger screws so that you have this wild assortment of sizes when you go to close things up and you have to figure out what size went where. You end up using larger screws in some iffy spots so that you have small screws left over and have to go get some more larger screws. An owner pays for that sort of time at every annual or oil change, and he'd save money in the long run if he just had the shop replace every nut and be done with it.

I don't think SKybolt has a kit for those old non-shockmount-cowl 172s. Edit: They do. https://store.skybolt.com/conversion-kits-c172c2800p-c347.aspx
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Yep, I called and asked, after finding the kit on their web site. They estimate 4-6 hours to install for a 172M; we'll ask our A&P for his best guess, too, of course. Opinions are all over the place - looks like Skybolt started out with issues, and did refinements as time went by. So we'll spend the approx $1300.00 it'll take to get 'er done. Hope for the best, but if it goes South (bad pun, I'm sorry), we'll move on to screws. Southcos just aren't cutting it, and we've dropped some $$$ on dealing with those, as well. Neither the design, installation, or the material quality does it for me.
 
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