One of the most common problems repair shops see with automatic transmissions is failing to shift or slipping when accelerating. If your car is doing either of these things, there are some things the auto transmission repair shop needs to check when trying to resolve the issue.
Fluid Level And Condition
Automatic transmissions work based on fluid pressure inside the transmission, so if the level falls too low in the system, the pump may not be able to build the required pressure for proper operation. The auto transmission repair shop will check the fluid level in your vehicle, and add some if it is low. Adding fluid may change the behavior of the transmission.
The auto transmission fluid condition is also essential. If it is thin and old, it may not be working efficiently in the system, and changing it could correct the problem. Old and thin transmission fluid needs to be flushed out of the system to ensure the new fluid is not contaminated when refilling the transmission.
The transmission flush will clean all the old fluid out of the transmission, the cooling lines, and the transmission cooler. Once the flush is complete, the tech will refill the system and recheck it to ensure it is operating correctly.
The transmission in your care needs a specific amount of pressure for the valve body to work correctly and ensure the clutch bands are seated so they will not slip. If the pump inside the transmission is not working correctly, the system pressure can fall low enough that shifting becomes erratic and transmission slipping becomes a problem.
The auto transmission repair tech can check the pressure in the system, and if the pressure is low, they may need to remove the transmission and inspect the pump. The pump is located in the front of the transmission and is powered by the engine in the car.
Because of the location, the transmission needs to be removed from the vehicle to get to the pump. Once the transmission is on the workbench, the tech can take the pump out and inspect it for damage or wear. If it needs replacing, this is the best time to do it.
While the transmission is out of the car, the tech will check the rest of the parts to ensure everything is in good shape and should change the oil filter screen before reinstalling the transmission. They will inspect the case for damage, replace any leaking gaskets, and then reinstall and fill the transmission.