Or buy a real tranny pan that has one built in.

 

the BG fluid exchane system uses the vehicle's fliud pump so it is near impossible for it to damage the seals in the tranny. the nightmare stories are usually from shops that use a machine's pump and that pump over pressurizes the system causing failures. the other benefit is that you actually get all of the old fluid out, they run aprox 1 1/2 the amount of capacity of the trans after driving the vehicle with a cleaner added to the system to loosen all the old gunk inside. i have done this on all my old vehicles and plan on doing it to both of the new ones soon. BG will also warranty the transmission (not sure for how long but long) if flushed and using their fluid every 30k. i use all BG fluids in my vehicles. the last sample from the wife's charger taken with 7500 miles on the oil and 22500 on the clock came back with a recommendation to push it to 10k changes. pulling a sample sat and sending it in for the truck. 25000 miles and 7500 on the oil. we will see.