Transmission Repair & Service Sarnia, 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.

Learn More
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.

Learn More
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Customer Reviews
Great team and helped solve...
Dakota Monk
Great team and helped solve a really unique transmission issue in my car. Would highly recommend
Date: April 11, 2024
Website: Google
Hands downs best service and...
Nathan McGuire
Hands downs best service and knowledge I’ve received in Sarnia. Hats off to Bob Munday and his team at Mister Transmission
Date: April 5, 2024
Website: Google
Took our gmc 4500 cube...
Ken Morris
Took our gmc 4500 cube van in for transmission flex plate service. They looked at it for 30 seconds, heard what it was doing, said just put a starter in it, it'll be fine. They were right. Replaced starter myself in less than an hour. Will definitely recommend them.
Date: April 5, 2024
Website: Google
I was Referred to Bob...
Briar Armitage
I was Referred to Bob & the team from Muffler man down the street. Everyone at Mr Transmission was very professional and they helped me out right away. Thank you so much for great service and for being so friendly and polite!
Date: February 17, 2024
Website: Google
Awesome staff, very knowledgeable. They...
Loadz Z
Awesome staff, very knowledgeable. They did a great job at explaining my transmission issue and making the necessary repairs. Highly recommend this shop.
Date: February 1, 2024
Website: Google
Fixed the car took a...
Logan Wilkie
Fixed the car took a bit of time being a Audi tt and hard to get parts but they where able to and fixed the car correctly took it to a different shop 3 times before going here and probably could have saved a bit of money if this was the first stop but it did take a bit of time with delays on parts replaced duel fly wheel, transmission and clutch
Date: December 22, 2023
Website: Google
Outstanding work and they are...
Jo-Anne Pfoh
Outstanding work and they are clear and up front
Date: December 17, 2023
Website: Google
Gave us great info...fixed a...
Diane Belanger
Gave us great info...fixed a problem that other businesses were unable to fix...trustworthy.
Date: December 5, 2023
Website: Google
From the moment Bob Munday...
Brandon King
From the moment Bob Munday picked up the phone, to Bob handing me my keys to my car with a new transmission installed, my experience was excellent, respectful, informative, and very professional. Mister Transmission did a great job!
Date: December 1, 2023
Website: Google
While most shops told me...
Larry Clarke
While most shops told me they were booked solid and could not get me in for almost a month, you offered to slip me in and did a great job. My truck is running much better and no more vibration...
Date: November 14, 2023
Website: Google
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