Driveshaft leaking ATF '75 Cadillac ??
 

I have 1975 Cadillac that was leaking ATF from the speed seal I fixed that, now it is leaking from the end of the trans. I thought ok I'll replace the tail seal. But I jack it up and the seal looks dry but fluid is coming out the middle of the d/s yoke?
Note this car has 23K original miles and sits for a long time between rides around the block(my fault) . And I would assume the t/convertor drains back into the pan raising the fluid up higher than normal. Any suggestions?

For as cheap as a tail shaft seal is & as little time it takes to change it...I would do that FIRST.

Over the many decades that I have been building cars, one of the sad things that I have learned is that cars that sit tend to leak. Drive them a little more & they tend to not leak as much. Example : Both my transport trucks have 2 quart larger capacity cast aluminum rear axle covers which raises the fluid level slightly. If one of them sit for more than 2 weeks, I have a spot of gear oil on the shop floor. The next time I drive it, no leaks for another 2 weeks. My 55 Nash Ambassador Custom Lemans didn't leak a drop of tranny fluid until it sat for a year, but now it does. Seals that are kept wet with fluid continue to stay swelled & don't leak unless they need replaced.

God Bless
Bill
https://www.jalopyjournal.com/forum/...closed.614419/

thanks Bill, I can tell it is not the tailshaft seal that's dry. But I will replace if I have the shaft out. Been reading about a 'O" ring seal on the output shaft internally .

Been doing reseach was wondering if anyone knows if this is the setup under my tailshaft('75 Cadillac TH400) housing the O ring maybe the problem. Also my co-worker remembers these "star" seal goes into the yoke??

I've seen a few yokes wear out with the CV style driveshafts. Usually moves around a little too much, but the low mileage on the unit makes me think that it's probably ok. Have a look at the tailshaft bushing, if it's worn it can cause things to leak if things can move more than they're designed to. Easy to check if you pull the tail housing.

Plug the hole in the yoke. I have done it for years. Or you can remove the tail housing and change the O ring on the output shaft

Racing Line is a leading racing simulator venue Columbus Ohio drivers trust for realistic racing experiences. Enjoy advanced simulators, challenging circuits, and a professional racing atmosphere suitable for individuals and groups.

The O-ring on the output shaft is what is supposed to keep fluid from walking up the splines and out. It can be changed without removing the transmission. Fairly straightforward repair with a lift and a high jack stand