The original C4 in our 66 was doing that...appeared to be a pan gasket leak but no way to cure it.  Finally cleaned it and checked the shifter shaft seal real close and that was the culprit.  ATF was traveling along the rail until if found a low spot to drip off.  Ended up going to the AOD before fixing the C4.

BB

OK, I suspect you may be right about the shifter seals. That is new territory for me so I'm not sure that I should tackle it on my own - but if it is not overly onerous I may decide to. Just on spec I called a local tranny shop and was quoted $225 to replace the seals and, of course, the pan gasket and filter. Sounds high to me. Any thoughts on that? Thanks for any help. 

Last edited by riwall (3/16/2018 6:26 PM)

Yup... pan and valve body have to come out, then you can pull the kickdown lever out (from the inside) and then remove the shift lever nut to pull it out (from the outside). If you do it yourself, usual things to look out for on disassembly are the converter drainback valve (under a tab on the filter) and a small basket filter in a large channel at the front of the case (usually stays in place). Things to look out for on reassembly are the location of where the kickdown lever is in relation to the kickdown valve on the valve body and the same for the pin on the shifter lever and the notch in the shifting valve in the valve body.

I would say that $225.00 is a fair price for the job if you want someone to solve the problem for you. It's not a hard job to do, just pay attention to details and if you run in to problems you can't get answered here then ask the guys at the Ford Transmission Forum.

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The pan is new and straight. My shop manual lists the torque limits for the pan at 12-16 ft-lb. I thought 14 was a good compromise. 

Well, I'm ready to try anything. Are the rubber gaskets better than the cork?

I've read all the replies and haven't seen the one that my '68 had. The filler tube has a O-ring where it goes into the transmission. Let her sit a couple months (Winter) and it would leak down enough to not even shift into Drive until a few seconds passed. I did the same pan gasket change twice and the second time I realized it was leaking down to the level of the pan. There was a pea sized piece of gravel where the tube goes into the pan that had distorted it enough so the o-ring wouldn't seal. If you ever head the heads off, you had to remove the filler tube brace and that's when I think it happened. Didn't show up right away, though. I think that O-ring finally got hard enough to no longer seal. New O-ring and it hasn't dripped a drop in over 6 years.

I prefer no gasket, replaced with ultra black RTV like newer cars use. Just don’t overdo it.  Let it dry before adding fluid.

OK, if I remember correctly, there is a brace that holds the filler tube in place. Once that is disconnected the tube can be pulled straight up. Is it as simple as that to remove it? Thanx 

Thanks for the tip Steve. I'll get some O Rings today and give this a shot. Seems like the gasket thing is a matter of personal preference. I've heard some guys say that they will only use cork and have never had a leak. Then I've heard others say that the cork gaskets are crap and they will only use the rubber/composite gaskets. MS, whose advice has always been solid and worthy of heeding, sez he only uses Ultra Black RTV without a gasket. I guess it is a matter of "more than one way to skin a cat". 

Yes, I'm an idiot! After 3 gaskets and a new transmission pan I checked the filler tube and it was wet. Looks like the fluid was seeping onto the rim of the pan and then moving to the rear before dripping off. Shoulda listened to ChrisH IA and mrputz1 earlier. I put in a new O Ring and so far so good. Oh well, if an O Ring can bring down the space shuttle I guess my ordeal was not such a biggie. Thanks to all for your help.