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
Completely satisfied
Harley Warszawski
Completely satisfied
Date: June 5, 2026
Website: Google
Friendly people, great service and...
Ricardo Sousa
Friendly people, great service and professional, I highly recommend Mr. Transmission
Date: June 5, 2026
Website: Google
Dan was very informative and...
Cory Lainey
Dan was very informative and very professional. Highly recommend !
Date: June 5, 2026
Website: Google
Amazing service and transparent Gus...
Mike Lee
Amazing service and transparent Gus was very helpful!
Date: June 5, 2026
Website: Google
Jordan from Mister Transmission is...
Kris Grude
Jordan from Mister Transmission is fantastic, patient over the phone, got my parents car in faster than any other shop could. Service was very swift and was able to communicate over the phone very well. Very fairly priced service for a transmission control module replacement, highly recommend for anyone looking for transmission work in the Niagara region.
Date: June 5, 2026
Website: Google
Pretty simple a pleasant experience...
Al O
Pretty simple a pleasant experience to deal with Joe and Juliano. Gentleman from start to finish honest work fair price. They took extra care of my 22 year old car ... Highly recommend if you want quality and honesty. Thanks guys ps Joe the car is not for sale LoL
Date: June 5, 2026
Website: Google
I'll return to this mechanic....
Lisset Acuña
I'll return to this mechanic. He is honest and straight up to the point. Awesome service!
Date: June 5, 2026
Website: Google
I’m very pleased with my...
Denielle Tooley
I’m very pleased with my experience at this shop! I brought my beloved Mustang here for a transmission rebuild. They were very helpful in explaining the process to me, communicating with the warranty company on my behalf, and keeping me updated on timelines without me having to ask for updates. I was delighted to pick up my vehicle and see they had gone above and beyond by washing it and putting some gas in it! All the staff I spoke to were pleasant and easy to work with. Mark took the time to explain things to me and ensured my full understanding throughout the process. I was encouraged to come back in about a week and a half for a final check up/inspection at no cost, which makes me feel even better about their confidence in their work.
Date: June 5, 2026
Website: Google
Regardless mine was best case...
Cameron McNaughton
Regardless mine was best case scenario, they were quick, great communication, well done
Date: June 4, 2026
Website: Google
Outstanding service from Chris (thanks...
C
Outstanding service from Chris (thanks also to Bill) - He gave me bad news about my car with grace, compassion, and most importantly; honesty. Chris' wealth of experience and knowledge helped me make informed maintenance decisions with confidence. My sincere and heartfelt thanks!
Date: June 4, 2026
Website: Google
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