On Wed, 9 Feb 2005 18:15:45 +0000 (UTC),
wrote:

snip

Holy crap... Superglue on an airplane? I was concerned that the minor seam
leak on my Lycoming O-360 was indicative of case fretting. Now I see that it's a
common problem and nothing to worry about. I guess I'll doublecheck the torque specs
on the case bolts and then get some RTV. It's only enough to cause a sheen on the
case after a long flight, so it's not enough to measure. Only disturbing thing is
what little gets blown on the side of the case goes through the jugs and seems to hit
the exact same spot on the muffler. There's a bit of a "burn oil" stain on it.

I'm not an engine overhauler, but have worked on quite a few. As you
might have figured out, on a Lycoming there is no gasket between the
case halves, just some permatex and a piece of silk thread (at least
that's what it useta be). My understanding is the silk thread is there
to help stop weeping oil leaks between the cases.

The cases that I have seen that have had fretting issues, the fretting
has been "inside" the engine at the bearing supports. I am by no means
saying that they cannot fret at the top seam, just that I am
unfamiliar with same.

I got the infamous TCM super-glue letter when I had a nearly new
TSIO-360 on a Turbo Arrow start weeping along the top seam. Was enuff
to make a big mess. About crapped myself when I read the letter, but
followed the directions and it worked like a charm. The part I liked
(aside from it stopping the leak) was that it was almost invisible.

The super-glue job lasted for about 4 1/2 years (through normal TBO).

regards;

TC