Transmission / Overdrive: Flight-O-Matic rebuild in order?

[Andy R.]

When replacing engine mounts, I discovered a leak in my FOM transmission that otherwise functions perfectly. After cleaning, it appears the fluid seems to be seeping through the selector shaft seal. About 4 oz. has accumulated in one month (sitting idle). The rest of the transmission exterior, including the pan, rear seal and filler tube appear to be dry. There has never been any leaking from the fill tube, so I can safely assume the vent is functioning.

Question: Can that seal (and pan gasket/filter screen) be replaced with the transmission in the car (without too much disassembly), or am I looking at a "leave it/rebuild it" proposition?

Thanks.

[karterfred88]

Never done it, but since my Avanti is starting to drip, so I did some "net surfing" and found this from a Thunderbird forum. I think most of it applies to you F-O-M. Seems it "can" be done but "ain't easy"

http://www.vintagethunderbirdclub.net/phpBB3/viewtopic.php?t=3738

[Andy R.]

Thanks for that link! Now that I know it CAN be done in the car, I have to figure out if it SHOULD be done. Seems the space between the selector shaft and the body tunnel is the most critical external measurement to take.

IF I decide to tackle it, I'll be sure to take/link LOTS of photos.