Community Member Credit: Kickinwing / Eddy
The 2016+ 8thgen Nissan Maxima does not come with a dipstick to fluid levels, unlike other generations. All new CVT transmissions from 2013-up are equipped with locking dipstick caps but no dipstick, with some Sentras and Versas being the exception to the rule. This was done to prevent the layman from screwing with fluid, etc.
Nissan service manual recommends changing CVT fluid when CVTF deterioration date is 210,000. The only way to check CVTF deterioration is through Consult-III+ scan tool. You can also do this with a CVT app on Android phones. The app is called CVTz50 and costs $5 bucks. You can read more about it here.
However, there is a way to check the fluid level. The service manual directs you to pump 2-3 quarts of NS3 into the overfill plug on the underside of the transmission. Not everyone has this fluid pump (ie. anyone that doesn’t work in a Nissan dealership.) The way around this is just to dump the fluid in through the dipstick tube with a funnel. It’s the quickest and easiest way around not having the fluid pump. The goal is to overfill the transmission by a quart or two. Next, you’ll have to hook up some kind of scan tool that can read transmission fluid temperature. The only way to monitor proper fluid level is by reading transmission fluid temp.
Hook up your scan tool, get the data monitor ready to view transmission fluid temp, and start the vehicle. Allow it to idle for ~10 seconds. While holding your foot on the brake, shift to reverse and hold it for ~5 seconds. Shift through all of the gears in this manner with your foot still on the brake to allow the fluid to work its way through the control valve assembly and all oil passages. This will ensure that the fluid in the pan is at the correct level. Shift back into park.
After you’ve done this, wait for the transmission to warm up to 95 degrees Fahrenheit. At this point, remove the 14mm overflow bolt on the bottom of the transmission. Fluid will begin to pour out, so be prepared. Monitor fluid temp while watching the CVT fluid flow from the overflow tube. Verify that the fluid slows to a fast “drip” before transmission temp reaches 113 degrees Fahrenheit. 95-113F is your temperature adjustment window. Once the fluid has slowed to a fast drip, install the overflow plug and you’re on your way!
In the event that the transmission was “too” overfilled and CVT fluid flow from overflow tube doesn’t slow before 113F, reinsert the overflow plug and allow the transmission to cool down. Lather, rinse, and repeat the above procedure.