Hi Everyone,

Thanks to the valuable info and help on this forum, I performed an ATF drain/fill on my I35 today. I bought this car a few months back and it has 72k miles on the clock. I did not know if the transmission had ever been serviced. The shift from 1st-2nd was a little jerky so I decided a servicing was in order. Though many people on the web say they had great luck with ATFs like Castrol Import, Valvoline, Mobil 1, Amsoil and etc., I decided to just go with OEM Matic D from my friendly Nissan parts dept. The entire procedure was a lot easier than I thought it would be. Below are the steps I went through and I hope it helps some people out:

1) I first drove the car around for a few miles to warm up the ATF. I then proceeded to lift the car with a jack and then placed one jack stand near the front driver side wheel.
2) Slide under the car from the front and on the driver's side and locate the black transmission pan. Nearly adjacent on the passenger side, you will find the oil pan. Make sure you work with the transmission pan though! The almost trapezoid-shaped trans. pan has 21 bolts running around it and has one large drain bolt in it. The drain bolt is readily identifiable, as it is quite large compared to the other pan bolts. Make sure to have some sort of receptacle underneath the pan to capture the fluid that will come out.
3) I used a 3/4 in socket to loosen the drain bolt. It was rusted on pretty good so I soaked it with some WD-40 for a few minutes. It then came right out. I made sure to grip the bolt well while removing it because I didn't want it to fall into my collection receptacle once the fluid started gushing out. As you remove the drain bolt, the old fluid will slowly begin coming out.
4) I went inside the house and let the old fluid drain out for like 30 min or so. As it drained, I noticed the fluid was a dark red, but not burnt or gunky.
5) Once the outgoing fluid reduced to a slow drip, I wiped off the drain bolt and hole with a paper towel and bolted it back into the pan.
5) I transferred the old fluid from the receptacle into an empty oil container with hash marks at 1 qt intervals. Appx. 5.5 qts of old fluid came out with this one drain/fill for me. From what I've read, the amount drained is usually from 4-6 qts.
6) Using a nifty ATF funnel I got from Advance Auto Parts for like $5, I opened the hood, removed the ATF dipstick and put the tip of the funnel into the dipstick hole. I then filled the funnel with about 5.5 qts of fresh Matic D fluid.
7) I removed the funnel, replaced the dipstick and started the car. According to Infiniti, the ATF level should be checked with the car idling on level ground, parking brake set and after the shifter has been moved through each gear range. The dipstick showed the fluid was in the proper range for the "HOT" condition.
8) Close the hood, stand back and gain satisfaction from performing this essential maintenance item on your own.

After driving the car around the rest of the day, I automatically noticed smoothness in the 1st-2nd shift. The other gear shifts have gotten tighter as well. I may perform another drain/fill in a few thousand miles just to flush out more of the old fluid circulating around.

Thank you for posting this. I will be helpful when I get around to doing mine.