How to Change Fluid in a 47RE

The 47RE is a type of automatic transmission that comes installed in the Dodge Ram model trucks that have the Cummings diesel engines. The 47RE is one of the larger automatic transmissions that requires a large amount of automatic transmission fluid. The transmission fluid needs to be changed at regular intervals so that the fluid will not break down. After the fluid breaks down, it will not be able to protect all of the moving parts, seals and o-rings inside of the transmission. The transmission pan will require removing to drain the fluid out of the transmission.

Things You'll Need

  • Drip pan
  • 1/2-inch drive ratchet
  • 1/2-inch drive socket set
  • Flat metal scraper
  • Clean rags
  • Red high temperature silicone
  • New transmission pan gasket
  • Torque wrench
  • Long neck funnel
  • 17 qts. Dexron-3 ATF
  • Park the truck on a flat surface and turn the engine off. Set the parking brake. Open the hood.

  • Raise the hood and remove the dipstick from the dipstick tube. Place the dipstick on a clean surface.

  • Slide a drip pan underneath the pan on the bottom of the 47RE transmission. Loosen and remove the front bolts from the front of the transmission pan with a ratchet, extension and a socket.

  • Loosen and remove the bolts from both sides of the transmission pan with the ratchet, extension and socket.

  • Loosen and remove all of the back bolts from the back of the transmission except for two bolts. Hold the transmission pan up with one hand. Finish loosening and removing the last two bolts from the transmission pan.

  • Slowly pull down on the transmission pan to separate it from the transmission. Tip the pan so that the transmission fluid will run into the drip pan. After all of the fluid is out of the pan, place the pan on the surface.

  • Remove the old gasket from the base of the transmission pan. Use a metal scraper to remove any gasket that is stuck to the pan. Use clean rags to wipe down the gasket surface until it is clean.

  • Apply a thin bead of red high temperature silicone around the gasket surface. Press the new gasket firmly around the gasket surface. Ensure that all of the gasket holes match up with the pan holes.

  • Raise the pan up to the bottom of the transmission. Screw two transmission bolts into the back of the pan and into the front of the pan to hold the pan in place. Tighten the front and back bolts down until they are snug.

  • Screw all of the remaining transmission pan bolts into the pan until they are all hand-tight. Finish tightening the pan bolts by using a alternating tightening sequence. Example: Tighten one bolt on the front, then tighten one bolt on the back of the pan until the front and back bolts are tight. Use the same alternating tightening sequence for the side bolts. Tighten a right side bolt, then a left side bolt until all of the side bolts are tight.

  • Torque each transmission pan bolt to 12 to 14 foot-pounds with a torque wrench and a socket. Use the alternating tightening sequence during the torquing process also.

  • Move to the top of the engine. Place a long neck funnel into the transmission dipstick tube. Pour 17 qts. Dexron-3 ATF into the funnel. Wait for all of the fluid to drain into the transmission. Remove the funnel and insert the dipstick.

  • Crank the diesel engine and let it warm up to operating temperature. Check the fluid level on the dipstick. The fluid level should be in the "safe zone" on the dipstick after 17 qts. Place the dipstick back into the tube.

  • Inspect the transmission pan for any leaks while the engine is running. Turn the engine off. If the pan is leaking, inspect the area and repair the leak as necessary.