Leaking Flange Studs

I would pull the ZF out of the car, the time you will spend messing around you be wishing you just pulled it. I would remove all studs and clean threads and use blue loctite.

Well, I called RBT to order new flange studs, as I could only back about half of them out by double nutting them. The rest had to be gorilla'd off with a vicegrip. They said they were too expensive from ZF and regular bolts would do fine as they only get torqued to 30 lb./ft. anyway. Thanks for the $ saving advice!!!
Anyway, I replaced all the studs and used blue loctite on the new bolts. They were fine, but I still had a leak. I was losing gear oil at a rate of about 7oz. per 100 miles.
I noticed there was always a drip forming on one of the four bolts in the lowest part of the cover, the one with the cushion clamps that hold the e-brake cables on it. And, oh yeah, the same one with the dab of silicone on it. But that couldn't possibly be my leak, 'cause when I removed it earlier to pull the trans out for my clutch replacement, I didn't get a stream of oil from the hole. Right? Wrong!
After pulling all four bolts, I saw it. A serious drip coming from that one bolt hole at a rate of 1 drop every 10 seconds.
So, I moved the cable clamps to another bolt, and reinstalled the offending bolt with some blue loctite. However, this only slowed the leak to 1 drop every 2 minutes. I reinstalled it again, this time using Permatex Aviation Form-A-Gasket. That thick dark dark brown stuff that looks like hot tar, which you brush on with the brush that comes on the cap of the bottle. The same stuff you use for head bolts where they go through to the water jacket.
So far, knock on wood, four days and not one drip!!!
Lloyd, is it a common problem for these gearboxes to develop leaks in such a manner? Do you think there's a crack in those threads or could the casting be porous in some spots? Obviously, this is supposed to be a blind hole, otherwise there'd be a stream of oil pouring out of these holes, no? Hmmm...

Thanks,
Eric Tolnes

You need to pull the pan off the bottom and replace the pan gasket, they are cork and will blow out after time.

I recently replaced all the nuts on the rear cover of my transaxle with stainless acorn nuts and brass washers. Before a small amount of trans fluid would seep from the studs. Now the rear cover is completley dry the acorn nuts and brass washers created a fluid tight seal. The same trick should work on the underside of the transaxle. If it works its a cheap fix and looks good too.

Thanks Lloyd. Of course, you're right about the gasket. Given the nature and the behavior of the leak, it couldn't be anything else. As long as the temporary fix works though, I'm gonna leave the tranny in the car until something more major prompts me to pull it. I don't think I can get the two long bolts out of the cover with the trans in the car due to the proximity to the frame rails. Correct?
I will be sure to replace the cover gasket next time the box is out. I promise!

Eric