How to Change Automatic Transmission Fluid in a Nissan Sentra

You should change the transmission fluid every 30,000 miles if you drive the car under normal conditions. However, under severe services, you need to change the fluid every 15,000 miles. The following covers Nissan Sentra models from 1982 through 1996.
Difficulty: Moderately Challenging
Instructions
Things You'll Need
Ramps or a floor jack
Jack stands
Wheel blocks
Drain pan
Socket wrench
New separator plate (if needed)
RTV sealant
New fluid pan gasket
Torque wrench
New transmission fluid
Funnel
1

Drive the car for 15 to 20 minutes to allow the engine to reach normal operating temperature. Park the car and turn the engine off. Raise the front of the car with ramps or a floor jack and support it with jack stands and wheel blocks.
2

Look for a drain plug on the transmission pan. Some models will have one, others won't. If there isn't a drain plug, continue to Step 3. If there is a drain plug, put a large drain pan beneath the plug, remove the drain plug and allow the fluid to drain. Skip to Step 4.
3

Use a socket wrench to loosen the retaining screws on the pan until you can gently pull one corner of the pan down. Take care not to bend or damage the fluid pan. Fluid will begin to drain. Remove the fluid pan retaining screws and take the pan off the transmission. Remove the old gasket and discard it. Clean the pan thoroughly and set it aside to air dry.
4

Remove the control valve body, oil strainer plate bolts and the separator plate. If the plate shows any scratches, dents or other damage, then you should replace it. Otherwise, you can reinstall the same separator plate.
5

Apply a thin bead of RTV sealant along the pan flange. The sealant should go on the outside of the boltholes, rather than on the inside. Align the new gasket onto the fluid pan and reinstall the fluid pan onto the transmission. Tighten the retaining screws evenly to 43 to 61 inch pounds with a torque wrench.
6

Measure the amount of transmission fluid that you drained from the transmission. Add the same amount of new Dexron II automatic transmission fluid to the transmission through the filler tube using a clean funnel. Replace the dipstick.
7

Start the engine, allow it to idle for a few minutes and shift the transmission through the gears, ending in "Park." Check the fluid level, which should be between the "H" and "L" marks on the dipstick. Add sufficient fluid if needed. Otherwise, replace the dipstick, close the hood and turn off the engine.