Switched to transynd today, was home alone and could not use "hoots" method, but I did change both filters. let the tranny drain till nothing came out, and unhooked both cooling lines and used compressor to blow old fluid out of cooler. The trans was full when I started, and it took abou 1/4 of a quart shy of three gallons to refill, is this enough to go to extended drain interval on trans.fluid. thanks

No, it's not. I did not get all of mine out and I put in right at 5 gallons.

Doug

I have an 04 GMC and my manuel says 24 qts for a complete flush and refill. 6 gallons!

Luckily my family owns a Valvoline quick lube station. I brought it in and we did a complete flush and refill. It took 6 gallons on the dot. I used Amsoil torque Drive though. Regardless a complete flush and refill will take 6 gallons.

Just had the transmission out upgrade to a stage IV PPE kit, Transgo and an ATS 5 Star TC. Put back in 5 1/2 gallons or 22 quarts of Transynd fluid. Have an Allison deep pan and a Mike L. cooler so that adds a little capacity.