Hey guys,

I bought my G35 at around 67k miles and just recently declined a "transmission flush" from the dealer since I read it did more harm than good. I've done a lot of research and read through countless threads about how I should just leave the ATF alone at this point but I've decided to drain and fill about 4 quarts every few oil changes until its all replaced. Knock on wood I haven't noticed any issues from the tranny yet but this is more to prevent any further degradation just in case.

The question I had was, I heard our cars came with J-Matic fluid and now apparently they no longer make that stuff but use "S-Matic" fluid, would mixing the two fluids like I plan to cause issues? I'm mainly against replacing all the oil because I don't think the previous owner ever replaced the oil and I read it could cause more harm than good. Anyone have any experience with this?

-Ash

 

At 100k I just replaced 3.5qts of my ATF. It was the cars first ATF change because of the nasty color. Runs the same, feels better for me. Next time I will be dropping the pan and doing about 5 quarts. It probably won't effect much but I will know it isn't an issue. To be clear S Matic is what we use now, so mixing shouldn't be an issue.

 

I have a 04 g35 coupe 115k miles bought it like 3 months ago. I forgot to ask the previous owner about service records. But anways the car is running perfect. I decided to change my ATF myself. I used Valvoline Max Life ATF (5 quarts) and also replaced the tranny filter while i was at it. Again, the tranny was shifting perfectly fine before i changed the fluid. I just changed it to be in the safe side. Its been maybe two months with valvoline and my tranny is still working perfect.

 

I'd really like to know how you check the dang thing...Bolted down cap....WTH????

Is there a dipstick in there?

 

Check and see. Or check the FSM for the transmission and learn.

 

Yes, it is a dipstick. Look at the FSM on how to measure it.

 

I changed my tranny fluid at 125k. The original J matic was still in there. Nissan did something different for me, they did a multiple drain and flush so they would do 4 quarts, run the car for 15 minutes. Then did it again 3-4 times. No problems at all and they put BG fluid becuase the S-matic was $150 more.

 

Matic S and Matic J are interchangeable, however, you should still be able to purchase the older fluid. I picked up a couple of quarts from my Nissan dealer. I used Idemitsu Type J in mine though when I did it. It's made to Nissan specs and I got a great deal online for it.

I did it around 60K at the dealership and myself at 120K. I have about 138K now on my car without issues.

It's the flush "machines" you need to be wary of. I think the dealerships use the actual transmission itself to flush out the old fluid. They basically unhook the the outline from the radiator and run the car until it comes out bright red. You can do this yourself as well if you have some help, but I did the drain and refill since I'm usually alone.

 

You really need to stay away from the stealership, they'll probably charge you $500 for a trans flush...which you don't need! Doing a drain/fill when you're having your oil changed is a great idea. Once you drained the trans there's not enough of the old fluid left to be concerned about. Experience with this? You're not the first to ask this question nor the last...Gary

 

Right! I wouldn't pay the dealer for a simple transmission oil change. I did it myself and my car is running perfect. I just removed the nut the let the fluid drain. Then put in 5 quarts of valvoline maxlife atf. Done, tranny shifts perfect. 5 quarts for like 30 bucks i think. It meets the requirements for infiniti matic j/s

 

"Meets the requirements?" AMSOL makes great AT trans fluid but put in print to use only Nissans fluid in our Infiniti G35s or Nissan Z! How can you argue with that? I wouldn't use anything but Nissan AT trans fluid regardless of what any members here use or recommend!
Gary

 

I would stick with what been in there all its life. Not to mention S-Matic is synthetic while Maxlife isn't.