Leaking trans fluid from weep hole in yoke

[Joe-NC]

'84 with TH350C. I recently replaced the rear seal in my transmission, but over a few days last week it leaked a huge spot (2' x 3') on my driveway from the weephole in the rear of the yoke. It dripped off at the U joint. I just drove it and kept a watch on the level, but didn't add any back. It has not leaked for a week now and the level is less than completely full, but still within the hatch marks on the dipstick.

I'm thinking my mechanic added too much fluid when he replaced the seal and now that the excess has leaked off, everything's fine. Have any of you ever seen this before? Is this what happens when you add too much fluid?

For a picture and description of a leaking yoke, here's a good link:
http://73-87.com/7387garage/drivetrain/yokeleak.htm

[txchainsawgogi]

there are two pieces that need to be replaced. one was the rear main seal, and the other is an actual O-ring inside the bell housing.

which did your mechanic claim to replace?

[beastie_3]

I think there was a post on this, see if you can find it in the search box.

[txchainsawgogi]

^excellent!

[Joe-NC]

I already tried the search box and I've read several threads about this. I understand that a bad shaft o-ring is probably the cause. Some have plugged the weep hole to solve the problem instead. My mechanic replaced the rear transmission seal. I bought it for him and watched him put it in. It doesn't leak a single drop. The leak was definitely coming from the weep hole. But before I pull everything apart, I was just curious if too much fluid could cause this leak. It has not leaked anymore in over a week and I haven't done anything but drive it, which leads me to believe that may have been the problem.

[txchainsawgogi]

I don't think fluid level would matter, if it leaked then the o ring is bad. Maybe now that the level is lower its putting less pressure on an already bad ring?

[Lt.Del]

o ring fur sure.  I had to replace mine and haven't had a problem since.

[ehjorten]

Usually they don't leak unless the vehicle has sit for more than a week.  The fluid level rises as everything slowly drains back into the pan.  I have had this problem on my Chevelle.  The o-ring was the culprit.

[Joe-NC]

Okay this makes perfect sense. I've been driving it almost everyday since the beginning of the month and it hasn't leaked a drop. Before that, it just sat for about a month.

[ehjorten]

It was so annoying in my chevelle before I learned about the o-ring.  Not every 350 has that o-ring either...just the ones with the weep-hole in slip yoke.