1. Check the Vehicle's Documentation:
* Owner's Manual: The owner's manual might list the axle ratio. Check the specifications section.
* Sticker on the Driver's Side Doorjamb: This sticker often contains information about the vehicle's options and specifications, including the rear axle ratio. Look for things like "Axle Ratio" or a similar designation.
* Build Sheet (if available): If you have the original build sheet from the dealership, it will definitively state the gear ratio.
2. Inspect the Differential:
* Look for a Tag on the Differential: The differential housing itself (the large casing holding the gears) often has a tag or sticker with the gear ratio stamped or printed on it. This is usually found on the top or side of the differential, but access may require getting under the truck. You might need a jack and jack stands for safe access.
* Calculate the Ratio (Difficult and Not Recommended): You can try to calculate the ratio by counting the teeth on the ring gear and pinion gear. This requires removing the differential cover (a significant job) and is only accurate if you have the knowledge and tools to do it safely and correctly. It's highly recommended against doing this unless you are experienced in differential repair.
3. Use a VIN Decoder:
* Online VIN Decoders: Many websites offer free or paid VIN decoder services. Enter your truck's Vehicle Identification Number (VIN), and it might provide the axle ratio in the vehicle specifications. Accuracy varies depending on the database used.
4. Contact the Dealership or Manufacturer:
* Dealership Service Department: The service department at a dealership, particularly one that handled the truck previously, might have access to your truck's service history and specifications.
* Manufacturer's Customer Service: You can contact the truck manufacturer's customer service department and provide your VIN. They may be able to locate the information in their records.
Recommendation: Start with the easiest methods (owner's manual, doorjamb sticker, and online VIN decoder). If those fail, contacting a dealership is a good next step. Avoid attempting to calculate the ratio yourself unless you are experienced in automotive repair. Incorrectly calculating the ratio or attempting to access it without proper precautions can be dangerous.
