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
image-reviews image-reviews
Customer Reviews
great shop - great employees...
Penny Barr
great shop - great employees and manager! So easy to deal with!
Date: January 9, 2026
Website: Google
Their great, best around
Greg Murphy
Their great, best around
Date: December 17, 2025
Website: Google
Excellent service. Great communication.
Nathalie Drew
Excellent service. Great communication.
Date: December 15, 2025
Website: Google
Fast, friendly professional
Tim Dagg
Fast, friendly professional
Date: December 14, 2025
Website: Google
My experience with Mr Transmission...
John Schrader
My experience with Mr Transmission here in Sarnia was very informative, from speaking with the owner he explained what needed to be done explained the process and the cost. I will recommend this business to anyone who asks! Thanks again!
Date: November 22, 2025
Website: Google
Recent service at Mister Transmission...
Sean Keane
Recent service at Mister Transmission was above expectations. Work was completed promptly and per estimate of cost. All of my questions were answered. Bob Munday and his team did a great job. Very satisfied with my visit.
Date: November 14, 2025
Website: Google
Very knowledgeable and great to...
Becky Nickels-Thomson
Very knowledgeable and great to deal with, highly recommend!
Date: November 10, 2025
Website: Google
Thank you Bob and crew...
Aleks Konte
Thank you Bob and crew on your great service. Come here for your transmission, transfer case and differential maintenance or repair.
Date: November 4, 2025
Website: Google
Great work by the Sarnia...
Rob Taylor
Great work by the Sarnia team....extremely knowledgeable on details of my old 1980 F150....replaced clutch in short order and works perfectly!
Date: October 31, 2025
Website: Google
Very quick service And friendly...
Jim Scott
Very quick service And friendly people.
Date: October 24, 2025
Website: Google
Mister Transmission Blogs
Recent Blogs
Dodge Transmission Repair: Symptoms Driv...
Dodge vehicles are known for their power, performance, and strong engines, but the
Read More
January 23, 2026
Ford Transmission Problems: Why Early Si...
Transmission problems in Ford vehicles rarely appear without warning. They begin as
Read More
January 15, 2026
Honda Transmission Replacement: Common W...
Honda vehicles are well known for their smooth performance, dependable engines, and
Read More
January 07, 2026
Transmission Rebuild Vs. Repair: Underst...
Your transmission plays a major role in how your vehicle performs on the road. It
Read More
December 31, 2025
Transmission Service Guide: Essential Ma...
Your vehicle’s transmission plays a major role in how smoothly your car moves,
Read More
December 23, 2025
Transmission Shop Near Me: What Drivers ...
Drivers often search for a reliable transmission shop near me when their vehicle
Read More
December 15, 2025
Transmission Repair: How Professional Di...
Transmission problems can start small but quickly grow into costly repairs when
Read More
December 08, 2025
Honda Transmission Replacement: Ensuring...
Honda vehicles have earned their reputation for smooth handling, fuel efficiency, and
Read More
November 28, 2025
Ford Transmission Repair: Professional S...
A Ford vehicle is designed to deliver reliable performance, smooth driving, and
Read More
November 21, 2025
Dodge Transmission Replacement: Keeping ...
A Dodge vehicle is built for strength, durability, and performance. Whether it’s a
Read More
November 14, 2025