ATF to Syntorq synthetic in trans, Gen 2

[SnakeWatching]

If I am changing trans fluid to Syntorq synthetic, do I have to flush/rinse the old ATF completely out of trans? Or just drain and refill? I did not know if any residual ATF would cause issues with new fluid. GTS has very low miles and has been inside most of its life.

[Drlee50]

Just drain and fill

[98RedGTS]

Thinking of changing my trans fluid to since I don't know how old it is. What are you using and what is the benefit of it over factory oil?

Also, can you fill through the shifter location like other t56's?

[Bugman Jeff]

Thinking of changing my trans fluid to since I don't know how old it is. What are you using and what is the benefit of it over factory oil?

Also, can you fill through the shifter location like other t56's?

The factory ATF filled cars sometimes had NGR(neutral gear rattle), basically the trans sounded like it was full of marbles though it didn't really hurt anything. There was a TSB about it, the fix was to change from ATF to the Syntorq fluid. It gets filled through the hole in the side of the trans. I suppose if you knew the exact amount of fluid you needed, you could fill it through the shifter, but it's less work and more accurate to use the fill plug, and it'll give you a chance to inspect your trans mount while you're there.

[SnakeWatching]

If I am changing trans fluid to Syntorq synthetic, do I have to flush/rinse the old ATF completely out of trans? Or just drain and refill? I did not know if any residual ATF would cause issues with new fluid. GTS has very low miles and has been inside most of its life.

Also I want to reduce NGR, that is one of the reasons for me to go to Syntorq in transmission.