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How to Change the Transmission Fluid on a Pontiac Montana

by Vanessa Padgalskas; Updated November 07, 2017

Items you will need

  • Transmission fluid

  • Funnel

  • Oil drip pan

  • Socket wrench

Changing the transmission fluid at least every 30,000 miles will help your transmission function properly. One sign that the transmission fluid needs to be changed is trouble with shifting. Your Pontiac Montana should shift smoother with new transmission fluid. Changing the fluid regularly is much better for the Montana than having a transmission fluid flush. A flush can circulate metal and dirt particles into the fluid and cause major problems in the transmission. 2005 was the final year the Pontiac Montana was produced.

Park the Pontiac Montana on a level surface so all the fluid can properly drain.

Pop the hood and remove the dipstick located near the rear of the engine. Set the dipstick in a clean location. You do not need to measure the level of transmission fluid before starting.

Slide under the minivan with a socket wrench and an oil drip pan. If you need more room under the van, use a jack to raise the van 6 inches.

Unscrew the drain plug lug on the transmission fluid pan. The drain plug should be easily visible and will either be on the side or the bottom of the pan. The bolts attaching the pan to the van are located on the top of the pan. You want to remove only the drain plug. The fluid will drain rapidly at first, so make sure the pan is underneath the drain plug before you unscrew it. Let the fluid drain for at least 10 minutes.

Clean the lug with a rag and screw it back on the pan. You are now done with the work underneath the van.

Measure the amount of fluid drained. You can use a measuring cup similar to the Radio-Rite measuring cup listed under Resources.

Put a small funnel in the dipstick tube and begin pouring the Dexron-VI transmission fluid. You must use a clean lint-free funnel that has not been used with any other fluids. Mobil 1 is a recommended brand. Pour the amount of fluid measured in Step 6. Try to be as precise as possible. You do not want to overfill the transmission. If you are unsure of how much fluid you drained, pour in a little less than what you measured. You can always go back and add more fluid after checking the fluid level with the dipstick.

Let the fluid settle by driving the van for 5 minutes. Measure the level of fluid by pulling out the dipstick and seeing if the fluid reaches the top mark on the end of the dipstick. If the fluid is low, add a little more and remeasure.

Record the transmission fluid change in a journal so that you remember to change the fluid again in 30,000 miles.

About the Author

Vanessa Padgalskas was born and raised in Spokane, Wash., and currently resides in Portland, Ore. Padgalskas graduated from American University in 2007 with degrees in international studies and economics. She holds a law degree from Lewis and Clark Law School.

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