How do I find out the gear ratio on my truck?
Understanding your truck's gear ratio is essential for optimizing performance, towing capacity, and fuel efficiency. Whether you're upgrading your vehicle, troubleshooting an issue, or simply curious, determining the gear ratio can be a straightforward process. In this guide, we'll walk you through the steps to identify your truck's gear ratio with ease.
What Is a Gear Ratio and Why Does It Matter?
The gear ratio refers to the relationship between the number of rotations the driveshaft makes and the number of rotations the wheels make. For example, a 4.10:1 gear ratio means the driveshaft rotates 4.1 times for every single rotation of the wheels. This ratio impacts your truck's performance in several ways:
- Acceleration: Lower gear ratios (higher numerical values) provide better acceleration but may reduce top speed.
- Towing Capacity: Trucks with lower gear ratios are better suited for towing heavy loads.
- Fuel Efficiency: Higher gear ratios (lower numerical values) often result in better fuel economy during highway driving.
Steps to Determine Your Truck's Gear Ratio
There are several methods to find out your truck's gear ratio. Here are the most common approaches:
- Check the Owner's Manual: The easiest way to find the gear ratio is by consulting your truck's owner's manual. Manufacturers often list this information in the specifications section.
- Inspect the Differential Tag: Many trucks have a metal tag attached to the differential cover. This tag typically includes the gear ratio stamped on it. Look for numbers like "3.73" or "4.10."
- Decode the VIN: Your truck's Vehicle Identification Number (VIN) can provide detailed information about its specifications, including the gear ratio. Use an online VIN decoder or contact your dealership for assistance.
- Perform a Manual Check: If the above methods don't work, you can manually calculate the gear ratio:
- Jack up the rear of your truck so the wheels are off the ground (ensure safety by using jack stands).
- Mark the driveshaft and the tire with chalk or tape.
- Rotate the tire one full turn while counting how many times the driveshaft rotates.
- The number of driveshaft rotations corresponds to the gear ratio. For example, if the driveshaft rotates approximately 3.5 times, your gear ratio is likely 3.55:1.
When to Seek Professional Help
If you're unable to determine the gear ratio using the methods above or if you suspect an issue with your truck's differential, it's best to consult a professional mechanic. At Kevin's Autos, we specialize in diagnosing and repairing all aspects of your vehicle, including drivetrain components. Feel free to contact us for expert assistance!
Conclusion
Knowing your truck's gear ratio is crucial for making informed decisions about performance upgrades, towing, and maintenance. By following the steps outlined above, you can easily identify this important specification. If you need further help, don't hesitate to reach out to a trusted auto service provider like Kevin's Autos for guidance.
Frequently Asked Questions
How can you tell the difference between a 3.73 and a 4.10 gear ratio?
If you have 4.10's, you will see the shaft turn just over 4 times when you turn the tire once. It may be hard to tell the difference between 4.10 and 3.73's with one turn of the tire. With 10 turns of the tire, you can easily tell the difference between 37 (for 3.73) turns of the drive shaft and 41 (for 4.10's).
Will the VIN number tell me the gear ratio?
You don't. That information is not contained in the VIN, UNLESS a specific model only gets one rear end ratio. VIN tells country of manufacture, vehicle make, class, engine type, size, date of manufacture, plant and serial number. That is the ONLY information contained by the VIN.
Where is the gear ratio stamped?
All right with the cover off and the gears wiped down you can see that there is some stampings on the outside of this ring gear. One of these is going to indicate the gear ratio.
How do you show gear ratio?
Gear ratios are presented as a quotient (e.g. 4:1) in which the first number is an expression of the number of teeth of the driven gear, and the second represents the number of teeth of the driving gear. So, if a driven gear has 64 teeth, and the driving gear has 8 teeth, the ratio would be 8:1.
How can I tell what gear ratio I have without pulling cover?
I have my buddy holding the other Tire. I start spinning this and I'm watching the other. One. That's one full rotation right there.
How can I tell what gear ratio by VIN Ram is?
The VIN won't tell you, but there's a sticker on the bottom of the driver's side axle tube that will list the ratio.
What gear ratio does my Ram 1500 have?
Ram has a standard axle ratio of 3.21 on 2X4 trucks and 3.55 on 4X4 trucks and trucks with the diesel engine.
What gets better gas mileage, 3.73 or 4.10 gears?
To keep it simple, if you want a daily driver and want to save a little on fuel and you care about performance but don't want screaming RPM, then taller gears like the 3.73 ring and pinion are the way to go.
How do I find my gear ratio on my truck?
The axle may have a sticker, and on the differential cover, you might have a small metal tag that's sticking out that will have the gear ratio stamped on it. Do a Driveshaft Turn Test. Before you can begin identifying the gear ratio, you will also need to know if the rear end is a “posi” or open differential.
What gear ratio is my transmission?
Here's the formula for calculating gear ratio: (RPM x Tire Diameter Inches) / (Final Drive Ratio x Transmission Gear Ratio x 336) = Actual numerical gear ratio to the ground from every revolution of the engine.
