Transmission Repair & Service St. Thomas, Ontario

Pinpointing the exact cause of any transmission problem takes skill, knowledge, and investigation

The evolution of transmissions has made these machines and systems increasingly complex. When transmission repairs are required, determining the cause and cure for what ails can be tricky. Why? Because transmissions have become remarkably complex and computerized and that presents both advantages and disadvantages. On one hand, transmission performance has become noticeably better in all vehicle makes and models. On the other, the increased complexity and digitization of transmission systems has made repair work a highly technical and complicated affair.


As you can imagine, there are different types of transmission repair jobs and options you can choose from depending on the nature of your vehicle’s breakdown. Understanding what those options are can help you make informed decisions when faced with a choice of transmission repairs to weigh.

A Repair for Every Type of Transmission Malfunction

Some transmission repair work is straightforward and mechanical in nature. Other times, it’s a combination of mechanical and electronic engineering that’s required to get your car back on the road. The most common types of repair work include:

  • Adjustments and in-car repairs. Most minor repairs are simple matters that are done without removing the transmission from the vehicle. If yours is a computer-controlled transmission that is not shifting properly, it is often the result of a computer sending incorrect signals due to a faulty sensor, or the transmission is not reacting to the command because of a bad connection or defective solenoid pack. If a non-computer controlled transmission is shifting too early or too late, it may require an adjustment to the throttle cable. If the vehicle has a vacuum modulator instead of a throttle cable, there is an adjustment that can be made using an adjustment screw in some designs. In vehicles with modulators, however, it is important to ensure there are no vacuum leaks and that the engine is running at peak efficiency.
  • Reseal jobs. A transmission is re-sealed to repair external transmission fluid leaks. If you see spots of red oil on the ground under the car, your transmission may need a re-seal job. To check a transmission for leaks, a technician will put the vehicle on a lift and examine the unit for signs of oil leaks. If a leak is spotted at any of the external seals or gaskets and the transmission otherwise performs well, the technician will most likely recommend that the transmission be re-sealed. Most of the external seals can be replaced while the transmission is still in the car but, if the front seal must be replaced, the transmission must first be removed from the vehicle to gain access to it.
  • Replacing accessible parts. There are a number of parts that are accessible without requiring the removal of the complete transmission. The parts that are accessible, however, vary from transmission to transmission and most transmission repair facilities would hesitate to provide meaningful warranties on external repairs for the simple reason that they cannot see if there are any additional internal problems in the components that are only accessible by transmission removal.
  • Complete overhauls. Also known as “rebuilding a transmission”, a complete overhaul involves the removal and disassembly of the transmission in its entirety. Every part is inspected for wear and damage, then cleaned in a special cleaning solution, or replaced with another part depending on its condition. Parts that have friction surfaces, such as bands and clutches are replaced as are all seals and gaskets. The torque converter is also replaced, usually with a remanufactured one. Technical service bulletins are checked to see if the auto manufacturer recommends any modifications to correct design defects that were discovered after the transmission was built. Automobile manufacturers often make upgrade kits available to transmission shops to resolve these design defects.

Replacing or Overhauling a Transmission

When a transmission requires an overhaul, there are two options that you may have. The first is to remove your existing transmission and overhaul it, then put the rebuilt unit back in your car. The second option is to replace your existing unit with another unit that has already been rebuilt or remanufactured.

A word to the wise: replacing your transmission with a used one may not be your best option. Used transmissions often have questionable histories that could create a whole new set of challenges. New transmissions, meanwhile, are mostly aftermarket transmissions billed as new but are in fact rebuilt transmissions with new parts.

The cost of the repair is always top-of-mind and understandably so. Transmission repairs are usually unexpected (and unwelcome). The cost varies depending on the outcome of our diagnostic testing, and we will help you to understand the various factors that come into play. We also offer our customers flexible payment options.

Whichever route you choose, you can trust our transmission experts to get you and your car back on the road.

Visit Mister Transmission for an assessment on what transmission repairs you may need. Contact the Mister Transmission service centre nearest to you.

Featured Services
Transmission Repair

The evolution of transmissions has made these machines and systems increasingly complex. When transmission repairs are required, determining the cause and cure for what ails can be tricky.

Learn More
Transmission Technology

At Mister Transmission we have access to leading-edge diagnostic equipment, enabling us to offer you the fastest and most accurate findings about what’s going on inside your vehicle’s transmission.

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Transmission Maintenance & Service

Just as you have other parts of your car serviced, your transmission needs maintenance to ensure a long life and avoid transmission problems.

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Customer Reviews
Tyler ,Mark and all the...
Danielle Graves
Tyler ,Mark and all the guys who work in the shop are amazing. They always going above and beyond to help with all my car needs. They are the most honest repair and oil change shop I have ever been too. I appreciate all you have done to help me the last 10 years since I moved to St. Thomas.
Date: February 6, 2026
Website: Google
This company is fantastic. Great...
Chris D
This company is fantastic. Great communication and pricing, excellent work, and they get it done fast. My car drives like it’s bran new after they installed a new clutch and flywheel and some transmission work. Mark and his team are extremely professional, I won’t go anywhere else for future work I may need done.
Date: January 7, 2026
Website: Google
I can’t thank Mark and...
Makaveli Makaveli
I can’t thank Mark and his team enough for their supports I been dealing with them for about two years now they are supportive and trustworthy mechanics I highly recommend this business. Thanks so much, Mark and all the team :)
Date: November 12, 2025
Website: Google
Have been coming to Mark...
Juan Juha
Have been coming to Mark for years for repairs to all my vehicles. He has always treated me fairly and given me the best possible options for my repairs. It’s like coming to see an old friend!
Date: November 10, 2025
Website: Google
Mark at the St. Thomas...
Andrius Sestokas
Mark at the St. Thomas location is extremely knowledgeable and trustworthy!
Date: October 29, 2025
Website: Google
I had gone to a...
Dawn Kenny
I had gone to a lube shop for an oil change at econolube in hamilton, and they took advantage of me as far as upselling and not doing the services properly or possibly at all. After that my car was chugging. When I called mister transmission, they told me to come in at my earliest convenience, and they checked everything over and got my car back on track. I am so grateful that they were honest and highly qualified people working there. Saint thomas mister transmission will be getting all my business now.
Date: September 18, 2025
Website: Google
When you want quality service,...
Mary Payne
When you want quality service, pleasant , family atmosphere come to Mr. Transmission. Excellent service, will give you truthful, information on your vehicle always wanting to ensure you are satisfied. Transmissions are their specialty, but they can fix anything. Give them a try 😄 😄 😄😄😄
Date: September 17, 2025
Website: Google
Amazing service! Great staff. Explained...
Sherry
Amazing service! Great staff. Explained what I needed to understand perfectly. Definitely recommend.
Date: September 10, 2025
Website: Google
Amazing service! Great staff. Explained...
Sherry
Amazing service! Great staff. Explained what I needed to understand perfectly. Definitely recommend.
Date: September 10, 2025
Website: Google
Fast friendly reliable and reasonable....
Pam Berdan
Fast friendly reliable and reasonable. Highly recommend
Date: August 28, 2025
Website: Google
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