How to Change a Transmission Filter on Chevrolet Carsby Contributing WriterUpdated June 12, 2017
A transmission filter helps remove debris or sludge particles that may build up in the transmission fluid as the fluid breaks down over time. You should replace the filter every time you change the fluid on your Chevrolet car unless you can have the transmission professionally flushed. If you are able to have the transmission flushed, consider replacing the filter every other flush in order to keep your Chevrolet car running in top shape.
Under The Hood:
- How to Change a Transmission Filter on a 2003 Monte Carlo
- How to Change a Transmission Filter in an '02 Blazer
- How to Change the Transmission Filter on a 1997 Chevrolet Pickup
- How to Change the Transmission Filter in an 03 Trailblazer
- How to Change the Transmission Filter in a 2002 Chevy Silverado
Removing the Filter
Drive your Monte Carlo for about 20 minutes to bring the automatic transmission up to operating temperature.
Park on a level surface. Apply the parking brake.
Raise the front of your vehicle using a floor jack and support it on 2 jack stands.
Chock the rear wheels.
Put on your goggles. Place a large catch pan under the transmission pan and remove the front and side mounting bolts from the oil pan, leaving the rear bolts in place. Use a ratchet, ratchet extension and socket.
Loosen the rear bolts four turns to allow the oil to start draining onto the pan. If necessary, tap the oil pan lightly with a rubber mallet to separate the oil pan from the transmission.
Hold the oil pan with one hand using a shop rag and finish removing the rear mounting bolts using the ratchet extension and socket.
Lower the oil pan carefully to a level position over the catch pan and tilt the pan to finish draining the remaining oil.
Remove the oil pan and gasket from the car.
Note the position of the transmission filter and pry it off using a large screwdriver.
Clean the oil pan thoroughly using solvent and a clean, lint-free towel. Scrape old gasket material from the oil pan and transmission mating surfaces using a plastic scraper and soft wire brush.
Installing the New Filter
Press the new transmission filter in place by hand.
Set the oil pan in place along with a new oil pan gasket under the transmission.
Install the pan mounting bolts using the ratchet extension and socket only.
Torque the oil pan mounting bolts evenly, using a crisscross pattern to 10-foot lbs (14 Nm). Use a torque wrench, ratchet extension and socket.
Lower the vehicle.
Fill the transmission with oil through the transmission dipstick tube using a funnel.
Start the engine and shift the transmission through all the gears and back to Park. Turn off the engine and check for oil leaks around the transmission oil pan.
Items you will need
2 jack stands
Large catch pan
Rubber mallet, if necessary
Clean, lint-free towel
Soft wire brush
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.
Items you will need
3/8-inch drive ratchet and socket set, with 4-inch extension
3/8-inch drive certified torque wrench
2 straight razor blades or box cutter blades
New transmission filter
New transmission pan gasket
6 quarts or more standard automatic transmission fluid (ATF).
2-gallon or larger drain pan
Place the drain pan underneath the transmission pan.
Loosen the bolts in the transmission pan far enough to allow the fluid to slowly pour out and into the drain pan. Loosen them progressively further to get as much fluid out as possible, lowering one end down further than the other as you go, which will force the fluid out of the transmission pan and into the drain pan. Once you have allowed most of the fluid to pour into the drain pan, remove the bolts completely and stick them in the magnet dish so you can find them easily when reinstalling the pan.
Clean the pan thoroughly with the brake clean and rags, making sure to remove any leftover gasket material from the pan. Use the razor blade scraper to remove any leftover gasket material that doesn’t come off easily. There is a particle magnet in the pan that may look like a fuzzy steel doughnut; the “fuzz” is comprised of tiny metal shavings that occur as normal wear and tear inside your transmission. Remove this magnet and clean it thoroughly with rags and brake clean before putting it back in the pan. Clean the underside of the transmission where the pan mates to it with the rags and scraper.
Pull the old filter down and out of the mounting hole, by grabbing it at the end where it mounts and twisting from side to side while pulling downward. Be careful, as the filter is still full of fluid.
Insert the new filter by pushing it firmly into place. Make sure it is fully seated before continuing.
Spray the transmission pan’s edges with a very light coat of spray adhesive, then place the transmission pan gasket on it, making sure to properly align all the bolt holes.
Place the transmission pan back against the bottom of the transmission and thread in all the bolts by hand, making sure not to cross thread any of them. Once they are all in, tighten them down fully with the socket set, moving in a crossing pattern as you go from bolt to bolt (i.e., tighten the upper left bolt, then the lower right, then the upper right and lower left, and so on, until the pan is fully sealed).
Put the fluid funnel into the transmission dipstick and fill the transmission with the recommend amount and type of transmission fluid. Consult your trucks owner’s manual for specific fluid information.
Items you will need
Razor blade scraper (optional)
Replacement filter w/new gasket
Replacement transmission fluid
Raise the car with the jack and support it on four jack stands. Place a drain pan underneath the transmission fluid pan and check to see if the pan has a drain plug.
Disconnect the shift linkage that runs along the driver's side of the transmission pan--disconnect the cable end from the ball stud and then remove the bolts that mount the cable bracket to the transmission--this is needed to access some of the transmission pan bolts.
Unscrew and remove the drain plug, using a flare-nut wrench, and let the fluid drain into the drain pan.
Remove the mounting bolts for the transmission pan, using the wrench, then carefully pry off the pan with a flat-head screwdriver. If the pan doesn't have a drain plug, remove all but the corner bolts and then slowly remove the front bolts, so that the fluid drains into the drain pan.
Pull the transmission filter straight down to remove it from the valve body inside the transmission.
Clean off all traces of gasket sealant from both the transmission and pan, using solvent and a rag. Dry the surfaces with compressed air.
Install the new filter in the transmission with a new seal; the seal is often pre-installed on most replacement filters.
Attach a new gasket onto the flange of the transmission pan, and then install the pan back on the transmission with its bolts. Tighten each bolt a little bit at a time, working around the pan's circumference.
Reconnect the shift linkage, using its bolts, and connect the cable end to the ball stud.
Lower the vehicle off the jack stands.
Fill the transmission with four quarts of Dexron III automatic transmission fluid through the filler tube at the right rear end of the engine compartment. Use a funnel to aid in pouring the fluid.
Items you will need
Transmission pan gasket
Raise the truck and support it on jack stands. Place your oil-drain pan under the transmission pan so it is directly underneath the drain plug.
Loosen and remove the drain plug with a flare-nut wrench and let the fluid drain into the pan. Install the plug back into the pan once most of the fluid has drained.
Unbolt and remove the heat shield on the transmission's right side using your wrench and then disconnect and unbolt the shift link cable from the left side.
Remove all of the transmission pan's bolts with the wench and then pry it off of the truck using a large flat screwdriver.
Pull down and pry the transmission filter off the transmission. Pry the seal out of its mounting hole in the transmission using a special removal tool.
Clean off the transmission's gasket surface using lacquer thinner or acetone.
Clean the inside of the transmission pan with a solvent. Dry off the pan with compressed air, as a towel can leave fibers that will contaminate the fluid.
Install the replacement transmission filter onto the transmission; make sure the new filter has a seal installed on it (most come with one pre-installed).
Connect the transmission pan to the truck with a new gasket placed on the inner flange. Tighten each of the bolts a little at a time with a torque wrench if possible until they are all at 97 inch-pounds.
Reinstall the shift-link cable and the heat shield.
Add four quarts of transmission fluid through the filler tube in the engine compartment with a funnel's aid.
Run the engine at fast idle with the truck in Park and the parking brake on. Shift into every gear and then back to Park. Let the truck idle a few minutes more and add extra fluid to the proper mark if needed.
Items you will need
8-quart drain pan
Transmission-filter seal tool
Dexron III automatic transmission fluid