I Just Got A Lift Kit And Bigger Tires, But Now My Truck Feels Slower!
So you picked up the truck you’ve been dreaming about, and had enough left over to go and get it lifted. You go to the shop to pick it up, looking through the window at it waiting for you. You can hardly wait to jump in and hit the road…
…but as you’re driving away, your excitement starts to fade. You’re putting the pedal down, but it just feels… slow. Delayed. Like there’s hardly any power getting to the ground. And the terrible news is – you’re not wrong. You’ve missed a key part, and your truck won’t feel right until you deal with it.
You didn’t get your axles regeared to match your new setup!
Putting bigger wheels and tires on your truck looks cool, sure, but it also adds more weight and a bigger load onto your engine. This means the truck feels slower, will be harder on fuel, doesn’t tow as well as before, and just simply doesn’t utilize the power from the engine as well as it used to. If you don’t regear the axles to match your wheel and tire setup, you’ll notice this drawback immediately as you take your first drive in your newly lifted truck.
At Schultz Diesel Sports, we can tune the engine to add horsepower and torque, compensating for the heavier wheels and giving a boost to the raw energy generated. But this isn’t a proper solution: all of that energy won’t be efficiently transferred to the ground, and the poor transmission is stuck in the middle, between the new found power on one end, and heavier/larger tires on the other. This is a setup that can cost you a transmission in no time!
The solution? A rarely discussed, but vitally important process – regearing your axles. This involves changing the gear ratios (i.e., how many teeth on the first gear in a system compared to how many there are on the second one it connects with) allowing for a more efficient transfer of power from one area to the next. This will give the drive train the mechanical advantage that was lost by the larger tires.
Generally, OEM parts are made for fuel economy, so stock gear ratios can be as high as 3.42. This can be alright for lightweight, aluminum wheels with relatively light 32” tires - but as soon as a heavier, taller setup is put on, the truck loses its efficiency. This makes the truck feel slow and sluggish, causes the speedometer to be inaccurate, in addition to increasing the potential for drivetrain failure (i.e. transmission and u-joint failures).
Regearing axles will solve these problems, and even more importantly – make the truck feel like it used to, without having to add any additional power or even having to tune it. The trick is that more power gets through the transmission and drivetrain, and thus to the ground, simply because the gear ratios are a better fit for the new wheel and tire setup.
Since a lot of our customers use their trucks to tow trailers, here are some of our general guidelines. If your tires are 35”, your gear ratio should be 4.10, and at 37” the ratio should be 4.56. Going even bigger, 40” tires should be (at least) 4.88. As the tire size goes up, the gear ratio goes down (numerically higher number), but this isn’t something that should be guessed at. If you have more questions about your truck and the correct gears for its setup and intended use, just get a hold of us and we can create a gearing package for your specific situation.
With SDS, you don’t have to worry about shoddy parts, either. We carry OEM gears for several major brands, such as Dana Spicer and AAM, and aftermarket performance gear sets for others, like Yukon and Nitro Gear.
Don’t let your lift kit be a letdown… talk to the pros here at Schultz Diesel Sports today!