'66 Calais trans fluid leak

[Chuck Swanson]

Drivable car, but sitting for many years, like around 1992.  Winched it onto my trailer a few times during pickup. and then storage.  However, last time winching down, looks like almost all the trans fluid leaked out.  Will get it on a lift to see if I can tell, but maybe the rear seal to driveshaft is likely culprit?  Maybe pan gasket?   It was only out of trailer for a few days, so not a slow leak.  It is back in trailer an no leaks at all since, so my guess is most leaked out (except converter of course)
Thanks, Chuck

[mario]

Could very well be the torque converter leaked down and overflowed through the vent. It happens on my t400 if I don't drive it often an I don't know why.
Ciao,
Mario Caimotto

[Cape Cod Fleetwood]

All old cars leak. If I don't take The Ark out for a good long gallop at least every 10 days to 2 weeks I get an oil drip, a power steering drip,  a tranny drip, and a drip from the rear end. Drive him regularly, no problem. Old cars, old parts, old seals. If you don't keep them on the road and beat on them a bit, they get angry and pee all over your floor. The Calais I'd clean up under really well with break cleaner and rags. Fill up with Dex6 to the full line on the dip stick. Drive a bit, check the fluid again, drive some more, check the fluid again, adding if necessary, until it stays full the tranny is hot and you put some miles on it. Then park it for a few days, you'll find out what's leaking... And if its not a 'dangerous' leak, like trip interrupting, let it leak, fluid is cheaper than parts and mechanics. I wanted Michael to change out my power steering pump. "why" cause it drips sometimes. "add more fluid"

etc

YMMV

[Joe G 12138]

           Don't panic yet. "65 TH400's can do that. With the angle coming off the trailer / flatbed, whatever fluid in there runs to the rear of the tailshaft. There is a breather hole in the center of the output shaft.  Motion will force oil out, but it's in the center of driveshaft yoke and hard to see exactly where it's coming from. It could be no issue once car is leveled up and topped off.
           However, after long storage, there could be a little surface rust on the output yoke on the transmission shaft. That's abrasive to the rear seal. It's possible it may need replacing now or soon. Clean yoke shaft up good when new seal goes in.
            Joe Gibeault 12138

[35-709]

Could very well be the torque converter leaked down and overflowed through the vent. It happens on my t400 if I don't drive it often an I don't know why.
Ciao,
Mario Caimotto

I think Mario's got it.  I have had the same problem with a TH400 that sat for a while.  You may well find that a little tranny fluid looks like a lot.  If you can drive the car or at least start it and run it through the gears on occasion, you may well find it takes care of the problem.

[bcroe]

I find it impossible to keep the old cars leak free.  I just take a
3 X8 foot duct sheet metal, bend the edges up, and shove the
drip pan under the car, done.  A hanging ball gets me centered
over the pan instead of running over it.  If a leak gets too bad
(frequent refills) I will see about fixing it.  Bruce Roe

[Chuck Swanson]

Thanks All...this all leaked out in one day, huge puddle   I will report back when I find/confirm.  Chuck

[bcroe]

If it leaked out the air breather in the yoke, you need to replace the
O ring on the output shaft that is supposed to seal inside the front
yoke.  That can be done without removing the trans. 

Come to think of it, maybe it is time to pull the trans and put in all
new rubber, before a catastrophic failure happens.  Bruce Roe

[Chuck Swanson]

If it leaked out the air breather in the yoke, you need to replace the
O ring on the output shaft that is supposed to seal inside the front
yoke.  That can be done without removing the trans. 

Come to think of it, maybe it is time to pull the trans and put in all
new rubber, before a catastrophic failure happens.  Bruce Roe

Good point Bruce!  Thanks!  I replaced the seal on my '66 vert so was not too bad.  Spent more time looking for my box of seals.  A week after I ordered one on eBay, I found my box of 24 seals    I finally sorted my 2 40' containers of parts, so much easier now to find stuff.  Chuck

[bcroe]

Yea, do both the outer shaft seal, and that big O ring.  The tail
can come off to do them.  Bruce Roe