transmission fluid change

[APEXi240]

I want opinions, not service manual facts please (fjwagner I'm looking at you...well, not literally, obviously).

I'm at 34,000 miles right now. 4AT and the fluid is darker than brand new, but not by much. I do 90% highway driving (50-80mph). Do I change it now, or can it wait...if so, till how long.

I plan on keeping this car until it can no longer safely transport me.

[Shad0wXCalibur]

I'm not fjwagner but I can tell you if you do mostly highway driving, the fluid can go up to 100,000 miles. If you wanna be on the safe side and make sure your transmission lasts a long time, you can go ahead and change it at 75,000 miles.

[biggie]

^ Yep.

[APEXi240]

Thanks guys.

[fjwagner]

I am honored, but sometimes you get what you pay for with free advice. Draining the AT fluid and replacing is relatively easy and inexpensive. I believe Nissan suggests 60k which is probably ok if you are going to be like most and sell the car before you see 75k miles. If you plan to keep a long time which you said you were, I would go every 30 to 45 k. AT are expensive to replace and this is one area where I am more aggressive than the maintenance schedule. BMW, Mercedes and some others are going to lifetime fill but most independent mechanics and myself (not that I know much) are just very uncomfortable with that. I changed our manual transmission and differential in an old BMW every 30 k and that car was on the original transmission at 175 k when we sold it. Fred

[Shad0wXCalibur]

^What he said works, too. Really, transmission fluid isn't that expensive so feel free to do that. I followed the 30k change with my old car because I did almost nothing but hard city driving but now I have a CVT

[sooner4x4]

Here is a first hand perspective based on a previous car (not a Nissan) that I bought new and kept for many years. I changed the auto transmission fluid myself at 30k, 60k, 90k, which on that car involved dropping the pan, cleaning the magnet, and replacing the filter. What a pain, but you really get to see the condition of the fluid and the transmission.

At 30k, the fluid was somewhat darker than normal and the magnet had a bunch of very fine metal particles (looked like very fine hair) stuck to it.

At 60k, the fluid was almost new looking, and the quantity of metal particles on the magnet was very few.

At 90k, the fluid looked basically like new and there was virtually no metal particles on the magnet. I decided then to not change the fluid after that based on what I had observed. (the car was totalled a couple of years later).

My V is fast approaching 30k, and I will be looking underneath it to see how to change out the fluid. I suspect it will involve removing a drain bolt, draining out what fluid comes out, and adding back that much through the dipstick. Does anyone know for sure if that is the correct procedure, and how much fluid to expect to add back? (so I can plan on how much to buy).

[alonsorules8]

If you like to do the old fluid change method by dropping the transmission pan and then refill your are only replacing 1/3 of the total transmission fluid.

There is a new way that most dealerships use that completely back flushes the transmission fluid by hooking up a machine to one of the two transmission oil cooler lines and replaces all 16 Qt.s of fluid with new fluid and a conditioner for the transmission parts.

That is the way I change my transmission fluid on my last car a 97 Chevy Camaro and that trans is still running without issue and has over 206000 miles on it. Also the fluid was flushed every 30k miles.

Now as for the CVT trans. Nissan recommends replacing the CVT fluid every 60K miles. I do not know how exactly they flush the CVT transmission, but suspect that it is in a similar method to the A/T flush guidelines.