What is a Shift Kit?

Today’s customers demand a transmission which shifts smoothly, is durable, and delivers excellent fuel economy all at the same time.

To accomplish these benefits we would install what is known as an automatic transmission shift kit, which is probably one of the most misunderstood upgrades in the automotive world.

Many people know the words, but not many fully understand what a shift kit truly does or why it’s desired. In short, an automatic transmission shift kit modifies the transmission’s shift timing in order to dramatically increase shift firmness and durability of the transmission components.

This is desirable because the automobile manufacturer’s engineers sometimes allow far too much shift overlap (when the transmission is actually in two gears at once) in an effort to increase shift smoothness. It’s this overly smooth, disconnected feeling that earned early automatic transmissions the label “slush box.”

While the extended shift overlap creates a very smooth shift, it also reduces the efficiency and durability of the transmission by making the friction surfaces work overtime. The added friction also creates excessive heat, which prematurely wears out seals and clutches.

Transmission shift kits can reduce this overlap time while improving the overall shifting action. By better utilizing the energy normally turned into heat by slipping during extended overlap, shift kits allow you to instead use that inertial energy for forward motion with quicker shifts, therefore you’re also able to notice improved city fuel economy.

Most vehicle owners are willing to live with the faster shift patterns in exchange for the extended durability and added fuel economy. Plus, the fact that shift kits can be installed in a few hours without removing the transmission from the vehicle makes them a logical upgrade.

We carry a variety of shift kits for most makes and models and would be more than happy to answer any questions you have. However, due to the fact that one misplaced shift valve or spring can result in a malfunctioning or damaged transmission, it’s highly recommended that you allow the experts at Mister Transmission to perform the installation of a shift kit for you. To have a shift kit installed in your vehicle’s transmission, please contact your local Mister Transmission.

Want to know more?
Visite one of our locations!

Mister Transmission Team

The Mister Transmission team consists of certified transmission specialists with decades of combined experience in diagnosing, repairing, and maintaining automatic and manual transmissions.

With over 60 years of service across Canada, our experts provide trusted, accurate, and up-to-date automotive advice to help drivers make informed decisions about their vehicles.

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Customer Reviews
Excellent service. Chris, Wes and...
Mandy Pickett
Excellent service. Chris, Wes and the rest of the team were fantastic!
Date: July 21, 2026
Website: Google
Awesome team. Transmission is now...
Yoshipark99
Awesome team. Transmission is now smoother and more responsive. 4L60E full rebuild. Great job and pretty fast. Cole from Tillsonburg
Date: July 18, 2026
Website: Google
One of the best experiences...
Wayne King
One of the best experiences I have at a repair shop. I had transmission problems that I expected would cost hundreds of dollars to fix. Ended up it was just some rust seizing a linkage - they cleaned it up and didn't even charge me anything works fine now and I couldn't be happier - will be recommending them to everyone.
Date: July 18, 2026
Website: Google
Mister Transmission just rebuilt the...
Julie Watton
Mister Transmission just rebuilt the transmission in my sprinter van. Called them on a Monday, Wes diagnosed the problem on Tuesday and van was ready by Friday! Wes was super knowledgeable, provided options and even showed me the problem. Chris at the front desk has excellent customer service! Very happy with the experience.
Date: July 18, 2026
Website: Google
Awesome team. Transmission is now...
Yoshipark99
Awesome team. Transmission is now smoother and more responsive. 4L60E full rebuild. Great job and pretty fast. Cole from Tillsonburg
Date: July 18, 2026
Website: Google
Awesome team. Transmission is now...
Yoshipark99
Awesome team. Transmission is now smoother and more responsive. 4L60E full rebuild. Great job and pretty fast. Cole from Tillsonburg
Date: July 18, 2026
Website: Google
Resolved my issue and provided...
C M
Resolved my issue and provided a loaner car as I was out of town.
Date: July 17, 2026
Website: Google
Amazing experience will definitely recommend....
Les Karapancsik
Amazing experience will definitely recommend. Took their time and easily found the problem that other shops could not find
Date: July 17, 2026
Website: Google
100% reliable. Excellent service deliver...
Jose Duran
100% reliable. Excellent service deliver by true experts
Date: July 17, 2026
Website: Google
We’re from Winnipeg and began...
Tara McLauchlan
We’re from Winnipeg and began having transmission issues just outside of Ottawa. We had our campervan towed to this location, where they went above and beyond with their service. Kristin was friendly and knowledgeable and kept us promptly updated to our repair status. Mike the service tech worked so hard to get us back on the road in a safe and timely manner. This location worked in communication with our Winnipeg location to honor the nationwide warranty, even though we were 6000kms over the warranty threshold. We are so thankful for all their hard work and kindness.
Date: July 17, 2026
Website: Google
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