I have a nuisance drip of transmission fluid from my 1999 MN6 FRC. It is just forward of the differential, where the two halves of the transmission body join. This probably indicates a leaking seal on the transmission output shaft. I don’t mind periodically topping off the trans fluid; the volume lost is almost nothing; but does it present the potential for an abrupt failure that could foul the track and interrupt my season with an unscheduled major repair? I do 10-12 track weekends per year.

There is always a potential for a small leak to turn into a big one...and always when you least expect/want it to happen

I would start preparing to drop the trans axle and replace the necessary seals. But short term, you could always apply and external bead of high temp RTV at the seam to stop the leak. I wouldn’t rely on that long term though.

Dropping the trans axle will give also you the chance to install a trans/diff brace and tackle other low hanging fruit (axle seals, trans mount, etc) if you haven’t done so already. Just do it, it’s a fun job!

Agreed, definitely not the ideal method. But probably would be fine for a brief time.

Either my T56 or differential is leaking, I'll see for sure afterwhile, currently doing remote bleeder.

Looking online a few days ago I saw something by Permatex that you spray on oil pans, engines, transmissions etc in several coats and it's supposed to seal non pressure leaks.

Normally I wouldn't consider using this, but I might try it, need to find out where the leak is coming from first.

"A sprayable sealer that forms a durable rubber barrier that stop leaks in minutes. The wicking action seals hard-to-reach leaks without the need for disassembling or removing parts. Designed specifically to target low pressure leaks in hoses, oil pans, differentials, transmission pans, fluid reservoirs as well as plastic, PVC and metal pipes, their connections and much more!. Eliminates the need for liquid additive sealers that can swell and foul internal seals. Resists common shop fluids. Note: In many cases, more than one coat will be needed to solve the problem. Level 3"