The Chevrolet S-10 Blazer was introduced in the 1983 model year. The Blazer name was used on both full-size and S-10 Blazers until 1995, when the full size Blazer became the Tahoe. The 2002 Chevrolet Blazer was the last Blazer made, as it was replaced by the larger Trailblazer. The 2002 Blazer was equipped with a 4.3-liter engine, a 4L60-E automatic transmission, and the choice of 2-wheel or 4-wheel drive. The transmission pan on the 2002 Blazer is underneath the belly of the transmission, just behind the bell housing or engine area.
Raise the front end of the Blazer using a 2-ton jack or a jack with greater capacity. Place jack stands underneath the front frame rails, just inside the inner ends of the lower control arms. The wider apart you place the jack stands, the lower the center of gravity and the more stability the vehicle has during the project.
Lay beneath the front bumper of the Blazer and slide your body behind the engine so you can physically access the transmission pan. The transmission pan on the bottom of the Blazer is a large aluminum shiny pan. It is just behind the transmission bell housing. The bell housing is the part of the transmission that flares outward like a bell where it is joined to the engine.
Place a 2-gallon or larger capacity drain pan beneath the rear portion of the transmission pan. Remove the drain plug from the bottom of the transmission pan and allow the transmission to drain for no less than 10 minutes.
Remove the 16 transmission pan mounting bolts with a 3/8-inch drive ratchet and socket, along with a 4-inch extension. The extension will give you greater reach and leverage during this portion of the project.
Remove the bolts on the rear of the pan first (facing the back of the truck), then remove the side bolts one by one, alternating sides towards the front of the pan. Remove the front bolts last. Removing the bolts in this manner ensures you control the flow of the residual transmission fluid as it comes out of the pan. Pulling the bolts from back to front will also help you from getting transmission fluid all over yourself.
Turn the transmission pan completely over so it drains into the drain pan. Rest the transmission pan on the drain pan but do not allow it to fall into the drain.
Remove the transmission filter mounting bolt near the front center of the filter. Use a 3/8-inch drive ratchet and socket with a 4-inch extension to turn the bolt counterclockwise until it is removed. Set the old transmission filter directly into the drain pan.
Remove the gasket material from the transmission mounting surface, using a straight razor blade or box cutter blade to scrape the mounting surface clean. Scrape the gasket mounting surface on the transmission pan clean as well, using a second razor blade. Discard the razor blades immediately into a trash can upon completion of cleaning the transmission and pan mounting surfaces. Do not leave sharp razor blades lying beneath the vehicle with you.
Install the new transmission filter and mounting screw into the transmission. Tighten the transmission filter mounting bolt to approximately 15 foot-pounds of torque, using a certified 3/8-inch drive torque wrench and socket.
Install the new transmission gasket onto the transmission pan. Make sure all of the bolt holes on the gasket align with the holes on the pan. Raise the pan straight up to install it onto the bottom of the transmission. Insert all 16 transmission mounting bolts and turn each bolt at least 3 times into the transmission. Do not tighten or torque any transmission pan bolts down until all of the bolts have been started into the transmission.
Tighten the back-side transmission pan bolts down from the center outward, using a 3/8-inch drive torque wrench and socket. Tighten the bolts to 35 foot-pounds of torque with the torque wrench. Do not guess or estimate your torque settings by trying to use a ratchet, as you will only cause the transmission to start leaking in the near future.
Tighten all of the side bolts and front bolts down from the center of each side, then outward. This tightening method ensures you spread the gasket evenly across the entire mounting surfaces of both the transmission pan and transmission. Reinstall the transmission drain bolt and tighten the bolt to 22 foot-pounds of torque, once you have completely installed the transmission pan.
Raise the Blazer using a 2-ton jack or a jack with greater capacity. Remove the jack stands from beneath the Blazer. Lower the Blazer to the ground.
Open the hood of the Blazer and remove the transmission dipstick. This is the yellow dipstick toward the rear of the driver's side of the engine. Insert a transmission fluid funnel into the dipstick hole. As you have completely drained the transmission, you will now have to fill the transmission. Insert 5-quarts of automatic transmission fluid into the funnel. Install the dipstick back into the transmission fill hole. Start the Blazer and check the fluid level on the dipstick. Add transmission fluid as needed until the transmission is full.
