blue95stang

About to change the fluid on my '02 GT tranny. Whats the capacity? been researching and have found alot of debate on it. Figure I will do it old school and fill it up little by little then check it. Also Tremec recomends Texaco-Havoline ATF Mercon for the 3650. And says to not us Syn. Anyone have history on the best ATF for the 3650?

Sxynerd

FlamingoGT

There was a TSB 04-15-6 released in '04 that covers an issue with the 3650s from 01 - 03 which is where the where the change to 3.0L(6.3 pints/3.2 Qt) fill came from. It also states to use Motorcraft Mercon ATF (XT-2-QDX), so it is probably safe to use any Mercon III fluid.

CopNaStang

Ithought they also changed it to Mercon V.

FlamingoGT

That may have happened since then, but to the best of my somewhat limited knowledge the III was for the 3650 and the V was for the auto (whatever the automatics were of that time, and maybe still are...)

As for synthetic, the 3650 was developed using Mobil1, but for some technical reason switched to the standard ATF when put into production. I believe it had something to do with the chemical properties of synthetic as opposed to dino. So no, I wouldn't use synthetic in the tranny.

cliffyk

I have run RP Synchromax in my '03 GT for over 60k miles, since I got it with 30k on the clock. I changed it at 75k and have had no problems of any sort.

TRUEBLUE3934

This information is correct! You should absolutely use this lower fill volume as the TSB calls out.

The general consensus I have heard is to use one of the synthetic ATF fluids of your choice. What ever you do, don't try the Special Concoction floating around which says to use TransFix! It is Super thick and the tranny won't shift worth a darn if you do.

I am having very good luck with the Mobil1 synthetic ATF in mine.
Good luck!