Leaking issues in my 200 4R - any gurus available?
If you think it might be coming from the vent then all you have to do it attach a long hose to the vent hose into a baggie or something to catch the fluid...this way you'll have your proof as to where the fluid is coming from. I would duct tape the baggie to the side of the transmission so it doesn't sag and leak.
Also, one more important thing........I researched these transmissions quite a bit before I put one in my Barracuda. I read one article about a guy who showed the best way to replace the 2004R filter for racing and heavy use. As it turns out the filter will "suck" air, if you don't take the effort to seal it with silicone around the edges. Do some research on this issue because the problem started after you changed your filter and air in the fluid will cause "foaming"!! I'm surprised Art Carr didn't warn you about this issue. Check this out:
