2 Reasons Why You Should Not Turn Rebuilding Your Car's Failing Transmission Into A Do-It-Yourself Job

14 June 2023
 Categories: , Blog


After being informed that your car's transmission is failing, you may have decided that it should be rebuilt instead of replaced to help save time and money. To further reduce the costs, you may be thinking about buying a rebuild kit and doing the work yourself. 

However, unless you have had prior experience rebuilding transmissions and know what clutch packs, planetary gears, and torque converters are, you should rethink your decision. Below are a couple of reasons why you should not turn rebuilding your car's failing transmission into a do-it-yourself job, and instead, have a qualified technician do the work for you.

1. Parts Inside the Transmission Must Be Removed and Replaced in the Right Order for It to Work Properly

One reason why you should forget about rebuilding your own transmission is that the parts inside the system must be removed and replaced in a specific order. The many gears, disks, and shafts that make up the internal workings of the transmission will only operate correctly when they are positioned correctly.

If you install the clutch pack incorrectly or align the planetary gears improperly, for example, you run the risk of seriously tearing up the transmission. An experienced technician will have the knowledge, tools, and experience to ensure that all parts are correctly replaced in the right order.

2. Improper Modifications to the Transmission's Electrical System With the Car's Computer Modules

Another reason why you should leave your transmission's rebuild to a professional is that you could mess up the car's computer modules. As part of the electrical and computer systems, the electronic control module (ECM) and powertrain control module (PCM) talk to each other and the transmission to let it know when to shift gears.

However, if you were to make improper modifications to the transmission's electrical system while rebuilding it, you could fry these modules or sever their connection to the transmission. A qualified technician knows how to work with the electrical system to ensure that it and the computer modules continue operating correctly.

Along with the above issues that come from trying to rebuild your car's transmission yourself without any prior experience, the job would not come with a warranty like it would if you had a professional do the job for you. You may also void any warranty on your car if it is still covered by the manufacturer. Instead of attempting to do the work yourself, contact an auto shop that offers transmission rebuild services to speak with a professional technician about having them do the job for you.