Can a tuner really ruin a transmission?

The answer is a renowned yes, tuners can, do, and will ruin transmissions.

The manufactures build vehicles with exact specifications in mind for performance, fuel mileage, emissions, towing, torque, and horsepower. When you increase the torque and horsepower of the engine and you do not increase the holding power of the transmission it is very likely that the transmission will fail. We see this several times a month.

Towing and horsepower

never go together, it is a recipe for disaster. The engine is producing all the additional power the tuner is asking for and the tow load is being dragged behind. The transmission is the link between the two trying to hold it all together. Think of it this way, you are pulling a 100lb load of rocks up the side of a cliff with your hands when someone adds another 75lbs to the load. If you don’t find a way to tighten your grip the rope will slip and burn your hands. If a tuner is being used it is best to keep it set at 50hp or less when towing and never exceed the manufactures tow limits. If not the torque converter and clutches can slip causing them to fail and overheat the transmission making it necessary to replace it.

Bolt on horsepower

is the worst, you can’t turn it down or off. The term bolt on is anything that is installed onto the engine that increases horsepower. Such as, bigger injectors, bigger turbo, nitrous, etc.

Typically, if there are bolt on performance items there is a tuner as well equaling at least 550 hp.