Transmission oil leak

If the leak just started right after you reinstalled the pan, that is the most common source. There's two things at work to cause the leak. The first is after the pan is removed, fluid will continue to run out of the middle of the rear of the pan surface for many hours. I've come back 24 hours later to find the gasket surface still wet and fluid dripping from it.

The second concern is the type of gasket sealer used. If you use a regular gasket, this isn't an issue, but it is normally sealed with a silicone gasket sealer. There are many products available, but I'm only familiar with the two sold by the Chrysler dealer's parts department. One is black. It stays more rubbery when cured and is easier to clean off next time, but it absolutely will not bond or seal through a film of oil residue. Both metal surfaces have to be perfectly dry.

To address that shortcoming, there is a gray silicone sealer that's best for this application. It will seal through a light film of oil. It cures a little harder so it's more work to clean it off next time. Either product will cure after the transmission fluid is added, so you can put the fluid in right away. No need to wait for the sealant to cure.

There's a couple of ways to address the dripping fluid. Start by cleaning off all traces of the old sealer from the pan and the pan surface on the transmission. I prefer to do this with an air-powered tool with a scuff pad. Wash the pan with Brake Parts Cleaner to remove the debris. Do the same on the transmission. Once the transmission surface is cleaned, you'll see fluid running down at the middle of the rear surface. We'll address that shortly.

Place the bead of sealer around the pan surface and set it aside where it's within reach. Now for the messy part. I like to stick my finger up into the hole where the fluid is leaking from, then curl it around to both sides and splash around to get as much fluid as possible to run out. You're emptying a small well that has to fill with fluid before it runs over and down onto the gasket surface. By splashing that fluid out, you'll have about one minute before the well fills up again and fluid resumes running out.

That minute is enough time to spray the surface down with Brake Parts Cleaner and dry it, and to grab the pan and stick it in place. Have a few pan bolts ready to run in by hand. Very little torque is needed on those bolts. I tighten them with a quarter inch drive ratchet and socket. The holes are in aluminum so they're easy to strip out. I have a couple of ways to handle that if it happens.

As long as you get the pan in place before any fluid runs onto the sealing surface, the sealant will do its job even when the fluid resumes running down. Once the pan bolts are tight, you can put the new fluid in right away.

A former coworker had a different method to fight the dripping fluid. He would stuff a rag up into the hole the fluid was running out of, then he'd have a helper quickly yank the rag out as he popped the pan in place. It's pretty hard to do it this way by yourself because you don't get much time to get the pan in place. I prefer my method because I don't have to find a helper, and I can work at a more leisurely pace.

There are other gasket sealers from other suppliers that can work just as well as Chrysler's products. I'm not familiar with them so you'll have to discuss them with the people at auto parts stores. They'll tell you which ones their regular customers prefer.