How do I find the axle ratio on my Chevy Silverado 1500?

The quickest way to confirm your Silverado 1500’s axle ratio is to check the driver’s door jamb sticker, which typically lists the axle as a number (for example, 3.42 or 3.73). If that sticker isn’t available, you can also pull the information from the original window sticker or build sheet, or by decoding the VIN or inspecting the rear differential tag. This guide walks you through the most reliable methods, year by year and one for DIYers with basic tools.

Where the axle ratio is most commonly listed

Below are the most reliable sources to locate the axle ratio on a Silverado 1500. The list covers on-vehicle labels, documentation from the factory, and post-purchase options for verification.

• Door jamb sticker: Open the driver’s door and read the label on the door frame. Look for a line labeled “Axle” or “Axle Ratio” followed by a number like 3.42, 3.73, or 4.10. This is the factory-reported axle ratio for that vehicle’s configuration.


• Original window sticker or build sheet: If you have the factory window sticker or the vehicle’s build sheet, the axle ratio will be listed under drivetrain specifications or axle information. These documents are often found in the glove box, under the seat, or can be requested from a dealer if you don’t have them.


• Rear differential tag or stamping: Some owners check the rear differential itself. A stamped or sticker tag on the differential cover or the axle housing can indicate the gear ratio. You’ll typically see a number like “3.42” or “4.10” stamped or labeled there.


• VIN-based decoder or dealer inquiry: If the sticker and build sheet aren’t accessible, you can use the vehicle’s VIN with a GM VIN decoder or by asking a Chevrolet dealer. Many online VIN lookup tools will return axle information when the VIN is entered, or the dealer can pull the exact axle ratio from GM’s database using the VIN.

Confirming the axle ratio from multiple sources is a good practice, especially if you’ve bought a used truck or if aftermarket modifications might affect documentation.

How to use the VIN to confirm the axle ratio

When the direct label isn’t available, decoding the VIN provides a reliable alternative. The process varies slightly by year and trim, but these steps apply to most Silverado 1500s in recent generations.

• Locate your VIN: The VIN is typically found on the driver’s side dash near the windshield, inside the driver’s door jamb, or on the vehicle registration.


• Use a trusted decoder: Enter the VIN into a reputable GM VIN decoder or a trusted third-party decoder that includes drivetrain details. Look for the axle or rear end specification in the results.


• Cross-check with dealer records: If needed, contact a Chevrolet dealer and provide the VIN to have them pull the exact axle ratio from GM’s system.

Using the VIN is especially helpful if the vehicle’s documentation is missing or if the truck has unusual configurations or special orders that aren’t obvious from the door sticker alone.

Notes for different model years and configurations

axle options for the Silverado 1500 can vary by year, engine choice, 2WD vs. 4WD, and specific trim packages. Some common configurations include axle ratios around 3.42, 3.73, and 4.10, but your exact number may differ. Always prioritize the door sticker or official build documentation as the primary source, and use the VIN method as a corroborating check when needed.

If you’re checking a lifted or heavily customized truck, or a former fleet vehicle, variations may exist due to aftermarket parts or re-gearing. In those cases, the differential tag and the dealer’s records become even more important.

What to do if you can’t locate the axle ratio quickly

Start with the door sticker right away. If that’s missing or damaged, the window sticker or build sheet is your next best bet. If those documents aren’t accessible, inspect the differential tag or consult the VIN for a definitive answer through GM’s systems or a Chevrolet dealer.

In all cases, having the correct axle ratio is useful for towing calculations, fuel economy estimates, and any planned aftermarket gear work. Don’t hesitate to reach out to a dealership if you need an authoritative confirmation.

Summary

For a Chevy Silverado 1500, the axle ratio is most reliably found on the driver’s door jamb label, but you can also verify it via the original window sticker or build sheet, the rear differential tag, or a VIN lookup through GM or a dealer. When in doubt, cross-check with multiple sources to ensure you have the exact gear ratio for your vehicle’s configuration.

How do you tell if you have 3.73 or 4.10 gears?

You can tell if you have 3.73 or 4.10 gears by manually counting, checking the differential cover for a tag, or finding the ratio stamped on the ring gear. The most direct method is to lift the rear wheels, rotate one tire one full revolution, and count how many times the driveshaft turns; 3.75 turns indicates 3.73 gears, while slightly over 4 turns indicates 4.10 gears.
 
This video demonstrates how to check your gear ratio by counting the driveshaft turns: 48sBent Motorsports OffroadYouTube · Sep 22, 2023
Method 1: Manual count (with the vehicle jacked up)

1. Jack up the vehicle: Safely lift the rear of your vehicle and secure it on jack stands. Ensure the wheels are off the ground. 
2. Mark the driveshaft and a tire: Place a mark on one of the rear tires and a corresponding mark on the driveshaft. 
3. Rotate the tire: Rotate the marked tire forward one full revolution. For an open differential, you may need to lift only one wheel and have someone hold the other stationary, or lift both wheels and rotate one tire twice while the other tire is on the ground. For a locked differential, lift both rear wheels and have one tire rotate once while the other rotates once in the opposite direction. 
4. Count the driveshaft turns: Count how many times the mark on the driveshaft has rotated. 
   • 3.73 gears: The driveshaft will turn approximately 3.753.753.75 times for one full tire revolution. 
   • 4.10 gears: The driveshaft will turn a little over 444 times for one full tire revolution. 

Method 2: Check the differential cover tag 

1. Locate the tag: Look for a small metal tag that is usually bolted to the differential cover. It may be on one of the bolts. 
2. Read the ratio: If the tag is still present, the gear ratio will be stamped on it. It will likely be a number like "3.73" or "4.10". 

You can watch this video to learn how to find the differential cover tag: 51sFlawed OffroadYouTube · Apr 18, 2022
Method 3: Read the ring gear stamps 

1. Locate the ring gear: This requires removing the differential cover to get a clear view of the ring gear.
2. Find the numbers: Look for two numbers stamped on the teeth of the ring gear, such as "41" and "11". 
3. Divide the numbers: Divide the larger number (teeth on the ring gear) by the smaller number (teeth on the pinion gear). 
   • 41÷11≈3.7341 divided by 11 is approximately equal to 3.7341÷11≈3.73 
   • 41÷10=4.1041 divided by 10 equals 4.1041÷10=4.10 

This video shows how to read the ring gear stamps to find the gear ratio: 46sJL LIFE OFFROADYouTube · Nov 18, 2022

How do I know my axle ratio on my Chevy Silverado?

Identify your GMC or Chevrolet rear end gear ratio by the RPO Codes, usually located on the placard labeled “Service Parts Identification” inside the drivers door panel or glove box.

What gear ratio is the Silverado 1500?

The 2025 Chevy Silverado 1500 offers a 3.42 axle ratio on traditional gasoline models, or 3.73 on diesel models. The Silverado HD models offer 3.73 on all 6.6L V8 models, or 3.42 on Duramax models.

Does the VIN number tell you the gear ratio?

You may be able to tell the gear ratio from a vehicle's VIN by using an online VIN decoder, though not all manufacturers include this information in the VIN itself. If the gear ratio is included, it will likely be in the Vehicle Descriptor Section (VDS), which are the 4th through 8th digits of the VIN. For many vehicles, a sticker on the driver's side door jamb or on the vehicle's build sheet or owner's manual is a more reliable way to find the gear ratio. 
How to check the VIN

• Use an online VIN decoder: Enter the full VIN into a free online decoder. Some manufacturers have their own decoders, such as Mopar's decoder. 
• Look for the gear ratio code: Some VINs will have a code within the VDS that represents the gear ratio (e.g., "3731"). 
• Consult the manufacturer: If the VIN decoder doesn't provide the information, contact the vehicle manufacturer for assistance. 

Other methods to find the gear ratio

• Check the vehicle sticker: Look for a sticker on the driver's side door jamb or on the vehicle's build sheet. This sticker often contains detailed information about the vehicle's equipment, including the axle ratio. 
• Look at the differential: Some differentials have a metal tag with the gear ratio stamped on them, or there may be a sticker on the axle itself. 
• Consult your owner's manual: The owner's manual or other paperwork from the vehicle's purchase often lists the gear ratio.