How to Replace a Transmission Solenoid Vs. Rebuilding It

by Baptist Johnson
itstillruns article image
IT Stock Free/Polka Dot/Getty Images

The control solenoid is an essential component of the transmission system. It helps regulate the torque converter lockup, pressure control, and shifting and kickdown for passing gears. One common symptom of a faulty control solenoid is that your transmission may experience problems shifting gears. While in motion, your vehicle will slip out of gear. Problems with the control solenoid are often accompanied by you seeing the check transmission light illuminated on your dashboard. Once you have verified that your transmission control solenoid has gone bad, you need to repair it immediately. Consider replacing the component, rather than attempting to rebuild your entire transmission.

Step 1

Drive your vehicle to an automotive parts store. Ask a technician to connect a diagnostic computer code device to your vehicle. Most automotive stores will do this for free. Use the diagnostic code to identify which transmission solenoid has gone bad. Your vehicle may utilize as many as six solenoids.

Step 2

Purchase a replacement solenoid from the automotive parts store. Drive your vehicle to a safe place to complete your repairs. A well-ventilated garage may be a suitable option. Ensure the area you choose has an even ground and is fairly clear of obstacles.

Step 3

Park your vehicle and turn off the ignition. Apply wheel blocks to the rear tires to help prevent the vehicle from rolling while you are replacing the solenoid. Raise the front-end of the vehicle using a car jack. Place the front axles on jack stands to keep the vehicle elevated.

Step 4

Crawl underneath the hood area of the vehicle. Locate the transmission near the front of the hood area on the driver’s side of the vehicle. Inspect the transmission carefully. Notice that there is a fluid compartment attached to the bottom of the transmission. Place an oil pan directly underneath this fluid compartment.

Step 5

Remove the bolts that secure the fluid compartment to the transmission using a wrench-and-socket set. You may to try a few sockets before finding the right size socket for the transmission mounting bolts. As you are loosening the transmission bolts, transmission fluid will likely spill from the fluid container. This is normal and to be expected. Adjust the oil pan as necessary to catch the leaking transmission fluid. Set each bolt aside as you remove it from the transmission.

Step 6

Pry the fluid container from the transmission using a flathead screwdriver. Pour the remaining transmission fluid into the oil pan. Set the fluid container aside. Inspect the inside of the transmission. Locate the solenoid housing area. Notice that each solenoid is colored-coded to help you identify the different components.

Step 7

Locate the solenoid that you need to replace using the color-coded wires for assistance. Ensure that the color-coded wires match the color on the replacement solenoid you purchased. Inspect the solenoid for a mounting bolt. Remove the bolt using a wrench if you find one. Unplug the wire from the solenoid by simply pulling it away from the solenoid. Pry the solenoid from the transmission using a flathead screwdriver. Discard the solenoid.

Step 8

Apply a small amount of transmission fluid to the replacement solenoid. Ensure the O-ring is properly lubricated. Replace the discarded solenoid with the replacement solenoid. Press the solenoid into place until you hear an audible click. Reconnect the wire to the solenoid. Replace the mounting bolt, if you previously removed one.

Step 9

Wipe down the transmission fluid container using a clean cloth rag. Ensure that all the transmission fluid and old gasket material is removed from the container. Wipe as much fluid, metal shavings and dust from the container as you can. Apply a new gasket to the rim of the fluid pan. Do not use more than a thin bead or you risk damaging your transmission.

Step 10

Replace the fluid pan to the undercarriage of your transmission. Replace the mounting bolts that you previously removed and set aside. Allow the gasket to set per the instructions given on the gasket tube. Crawl from underneath the vehicle. Lower the vehicle to the ground. Refill your vehicle with new transmission fluid. While refilling your transmission fluid, check your fluid level often. Do not overfill your transmission.

More Articles

article divider