Help
Looks like you have lots of help. My 2 cents.
Don't be suprised if your new seal does not last long as most of the seal failures are due to either heat or bushing/convertor wear. The heat causes the pump and convertor to expand and this leads to the seal not being able to keep up with the size changes and lets it leak past. Most of the time, these will dry back up once the tranny cools down, but usually you are looking at some internal damage caused by the extreme heat (seals harden, clutches bake, etc...) The other one is caused by the convertor and pump being misaligned and prematurely wearing the pump bushing and allowing the convertor to sag and leak around the seal. This is where the bushing needs to be replaced and then remachined to fit properly. I get around it by using the convertor to align the pump when I install the pump into the bellhousing. Not exactly the right way, but it works for me....well except when I built mine, but I replaced my bellhousing and pump with a used unit from off of a core 5r55e when I built my Frankentranny. I stupidly did not replace the bushing, only the seal and it has leaked since it was installed. I will replace the bushing and seal when the engine comes out this winter. I hope you have better luck than me and your seal holds. Don't forget to stake the seal in the housing and replace the oring seals on the bellhousing if you removed it as they will leak if reused. This is a good time to readjust your bands, don't be afraid. Also, replace the jamb nuts on the bands if you adjust them as they have a tendancy to seep/leak if reused. If you must reuse them, then smear some silicone on the back of the nuts before you tighten them and it should prevent the unwanted seepage. I have four in my toolbox, but they don't do you any good in Colorado now do they? Also, inspect the bushing and seal surfaces on the torque convertor and make sure they are in good shape. Replace the convertor if you have any doubts. The Mercon V that is sold by FMC (Ford Motor Company) is compatible with the older Mercon transmissions (says so on the bottle) and I highly recommend it as it is a semi-synthetic or full synthetic (can't remember exactly now...seems like the SP is the full synthetic and V is just a semi). I run it in mine with no problems and it seems to stay red and smell good longer than regular Mercon. I am replacing the flexplate in my wife's truck when I replace the engine since they had problems with them and it might be a good idea for you to consider. I picked mine up for $50 but I also know the parts store owner. I think they retail for $75-100. Consider it cheap insurance...it is recommend by all the transmission remanufacturers that I deal with, they even send a little card w/ the reman units stating this and listing the old TSB number for it.
I guess that may have been more than 2 cents, but it's hard to say the way the dollar has been fluxuating in recent weeks. Good luck.
Jeff
