The International Cessna^® 170 Association

When removing the exhaust stacks, on of the studs backed out with the brass nut still attached. There appears to be no damage to the stud threads or the cylinder hole. Any thoughts on getting the brass nut off the stud and the stud back in the hole? I do not have a stud insertiontool as called for in the manuals. Thanks.

Bruce

Bruce,
Just get two nuts with the same thread as the stud, put one on, then put the other over that one and TIGHTEN them against each other. Then holding the INSIDE nut with a wrench, you should be able to take the brass nut off the other end. When putting the stud back in, just use two nuts tightened against each other to screw the stud in, then simply loosen the two nuts from each other and back them off. Use Threadlocker on the stud going in the cylinder. This method makes the stud like a bolt on the double nutted end. Be sure to torque the stud in to the correct tension. If this is not clear just E-mail me direct and I will explain clearer.
Good luck, Jon

Bruce, I do not recommend using any type of "thread locker" on a cylinder stud. Those studs become pretty corroded/rusted from exhaust heat, and it's far better to simply throw it away and buy a new stud. They come in various "over-sizes" when the female threads become worn (possibly explaining why yours may have come out.) I suggest you contact a reputable cylinder overhauler and have them simply send you a new stud. They're cheap and it's not worth risking getting a worn/old stud broken off in your cylinder to consider reusing a problem one.

(If you're in a big hurry to go fly, simply re-insert your present stud with the nut still attached. It's already the correct length.)

Half my exhaust gaskets were installed with red silicon and half were "dry". Any prefference, experiences, or opinions on which way is better? I am ussing the 1 time use crush gaskets. thanks.

Bruce

All gaskets are one-time use. I prefer the spiral-wound steel gaskets over the copper crush-types. They are normally installed clean and dry. (High-temp sealants are sometimes used by those with deformed flanges and eroded cylinder exhaust-faces, but they are a band-aid fix and not a permanent one. It rarely lasts very long, and before you know it, you've got a dangerous, high-temperature flame-thrower blowing under the hood.
Exhaust leaks are notorious for causing in-flight fires and failures, as well as genuinely high oil temps that can cause engine damage.

I am using the spiral wound steel gaskets - I mis-spoke in the last post. At last annual, the IA recommended using the silicon, but I'd much rather not as it is a mess now getting it cleaned off. These will go on dry. thanks.

Bruce

Does anybody know where to find exhaust studs and what is the part number. I couldn't find it on the Aircraft Spruce catalog.

It's been a while since I shopped for them but you need to go someplace that sells engine parts like Superior.

They come in standard and oversized.

If you want to get some studs in standard size, just to mock up the exhaust mind you to see how it fits, you can find them at you local automotive supply and even your Lowes Hardware store. I happened to know Lowes has them conveniently packed at a very attractive price.

I don't have my C-145 books here at home but looking at an old receipt for some cylinder work I believe the Superior part number for the exhaust studs is SA402151. The TCM p/n should be the same without the SA prefix. I also believe the p/n for the oversize studs adds a suffix (for example SA402151 P03).
There's an overhaul shop in Bremerton WA that I've dealt with for cylinder work in the past & they stock all these sorta parts. Avian Aeronautics 360-674-2244 fax 674-2551 don't have an email for them.
My receipts (from Sep 2003) show the exh studs at about $2 - $2.50 a shot. Plus s&h of course.
The brass nuts are p/n SA 22022, about 75 cents apiece as of 5 years ago. Get plenty, they're cheap, and just replace everytime instead of reusing.

Eric

Air Power, Inc in Arlington - use to be part of Van Bortels - sells them for $1.85 each. P/N 402151 with a description of stud .31-18-401851. This is not the oversize, this the replacement. Their phone number is 800-938-7278. Also, Sentry Cylinders in Ft Worth would have anything that you would ever need.

The stud in questin in the originalpost of this thread was repaced from El Reno Aiation. I believe they advertise in the Fly Paper/Quarterly. I went up one size (don't remember the exact specs) as per their recomendation. No problems at all.