I always have a small leak of trans fluid when my car is parked. It seems like it might be coming from the connector for the kick down/variable pitch. The piece itself seems loose when I grab it. Is it supposed to have some kind of retainer? Do I need to drop the pan to remove it to replace the O ring seal?
No retainer that I know of, but there is an O ring which seals it. I don't think you will be able to get it out without dropping the pan. https://www.transmissionpartsusa.com/TH400_TH425_transmission_case_connector_p/460-00046388a.htm https://www.transmissionpartsusa.com/searchresults.asp?Submit=Go&Search=+31252+
Yeah, it was time to change the fluid and filter anyway... (don't forget the new filter shaft O ring(s) and new pan gasket) Hint. Loosen the two front pan bolts but leave them in and then remove all the rest but on in back. After that, place your swimming pool under the pan, and then hold the back of the pan and remove the last rear bolt. Lower the back of the pan and drain, then hold the pan in place and remove the two front bolts. Much less mess.
A little of that form a gasket blue on the O ring ought to fix it, if it is not in too bad a shape. My TH400s have a pan drain added in back. Doesn't get every drop, but eliminates the huge mess. Bruce Roe
I didn't have a pan large enough to catch the trans fluid, so I grabbed one of the plastic garbage can lids and drilled a bunch of holes in the center. Flipped it over and put it over my drain pan. Worked like a charm. But the best thing I ever did was install one of those Chinesium polished aluminum T-400 pans with a drain plug. Makes like so much easier.
Thanks guys for all the tips. I was thinking about maybe using one of those large shallow plastic storage bins to try to catch the fluid, but that will probably ruin it for use as an actual storage bin.
Be Very careful when you unplug the wire plug (inside trans) from the connector. It has a tiny tab sticking out that locks it in a tab hole in the connecter. I had a spare.... Drain fluid I just drill a hole in the pan and toss It. I buy a new aluminum pan with a drain plug.. I bought this one you'll need longer bolts they are Allen & you will need Allen.. Also throw the gasket that comes with it in the trash. Other than that nice pan..https://www.summitracing.com/parts/sum-433884