I'm certain the fluid in my 2003 6mt coupe has never been changed..nothing else was..


I have a notch going into 5th that I'm looking to prolong the life of the tranny as much as possible.. what are you guys using? Redline MTL/MT90/ShockProof?? Amsoil? Royal Purple? Lucas? HillBilly terbacky spit? (I've seen it... goes along with the torque spec of "redneck tight")


Same goes for the diff.. I want to pick up the life saving fluids and have a flush-a-thon one Saturday soon.

 

Be prepared for a million different answers and brand humpers.

The 6MT trans needs a pure GL4 fluid, not GL5 or GL4/5, only pure GL4. The two best and common options are Nissan MTF and Redline MT85. I think Amsoil has a GL4 fluid as well. Most people seem to have the best luck with Nissan MTF, occasionally I'll see a notchy complaint about Redline when cold, but I haven't had any issues, I think they may have used MT90 (thicker).

For the diff, it needs GL5 80 W-90 fluid. They sell GL5 fluids in you local autoparts stores all day long. I think I've used Valvoline and/or Mobile (I've changed mine a few times now). I noticed a huge difference the first time I changed my diff fluid, with rear wheels lifted it was hard to spin the rear wheels, with fresh fluid it took off so much better.

 

Considering the difference is a VLSD is there an aftermarket solution with friction modifiers that anyone has had success with?

 

Friction modifiers are unnecessary with the factory VLSD. 80W-90 fluid is info strait out of the FSM.

 

I did the diff fluid change out on saturday, using Lucas Oil 80/90 that is formulated for limited slip. no issues at all, and feels great so far.
Picking up the trans fluid at the dealer this week to change out that, then I'm up to date on all the maintenance for awhile. Back to mods and tuning.