Used Gearboxes - How to Properly Clean Used Car Transmission Parts

Used gearboxes, especially those that have been remanufactured or reconditioned, should work like brand new. And with proper maintenance and cleaning methods, you can prolong the life of your used gearbox.

 Should you clean used car parts by yourself?

Although cleaning and maintaining used car parts such as used transmission should be left to the experts, nothing should stop you from doing things on your own. With the rising cost of living, you can opt for a do-it-yourself car maintenance. Cleaning used car parts may not be an easy task, but for those who are keen to doing simple used gearbox cleaning, below are some simple steps you can follow.

Step-by-step gearbox cleaning guide

Before you start the cleaning process, drive your car around for several minutes. Driving your car before cleaning the transmission is a clever way of allowing the buildup of sediment when the car reaches its normal operating temperature. This should allow for sediments to come a whole lot easier during the cleaning process.


Set your car on jackstands and make sure that the jackstands are set up securely and sturdily. Jackstands are much more preferred than regular car jacks. The reason for this is that with the use of jackstands, it’s a lot easier to reach the gearbox and other parts under the car, and jackstands are much more reliable.


Set the drain pan under the car’s gearbox oil pan. Loosen and remove the oil pan bolts carefully from the side and front. The front bolts should only be loosened. Carefully open the pan and let the fluid drain into the drain pan.


Remove the front bolds. Secure the gearbox oil pan with one hand and remove the bolts with the other. Drain the rest of the gearbox fluid into the oil drain pan.


Inspect the gearbox fluid and pay attention to any particles that shouldn’t be there like pieces of metal in the fluid. Metal in gearbox fluid could indicate that there’s something seriously wrong with your car’s transmission. It should be immediately checked by specialists.


Clean the oil pan using a solvent to remove residues without scraping the pan. You can also use a putty knife to scrape off residues from the pan. Replace the bolts that fasten the transmission filter.


Use gasket sealant to seal the mounting surface when the bolts have been set back into place. Press the gasket back into place firmly. Replace all the bolts diagonally into the gearbox pan.


Carefully lower the car from the jackstand. Open the hood, and remove the gearbox oil dipstick. Add some more gearbox fluid continuously using a funnel. Always check the level while pouring the fluid. When the fluid registers on the dipstick, start the engine and allow to run idle for several minutes. Look for leaks. Add some more fluid while checking the level and keeping an eye out for leaks. Pour fluid until you get the full line of the dipstick.


There you have it, quick and easy tips to maintaining and cleaning used gearboxes. Do this regularly to prolong the life of your car’s used gearbox.