How do I identify my Dodge differential?
To identify your Dodge differential, inspect the rear axle housing for manufacturer markings or a gear-tag, and cross-check the information with your vehicle’s VIN/build sheet to determine the exact axle model and gear ratio.
In practice, the identification involves looking for data stamps on the differential housing or cover, noting any "Dana," "Spicer," or "Chrysler" identifiers, and then decoding those markings through your VIN or service documentation to confirm the specific axle type and gear ratio that your model uses.
Where to look on the vehicle
Begin with the most accessible area—the center of the rear axle. On two-wheel-drive Dodges, the rear differential is often clearly visible behind the driveshaft. Four-wheel-drive models may have a front differential and a transfer case that also carry identifying marks. The markings you need can be stamped directly on the housing, cast into the cover, or attached as a small tag near the cover edge.
Front vs rear differentiations
Most Dodge trucks and SUVs from the modern era use a rear differential on the axle, while 4x4 models have a front differential as well. The identification process described here mainly applies to the rear axle, but similar markings may appear on the front case.
Next, look for the data tag or cast markings on the differential itself. A metal tag may list model information and gear ratio, while stamped codes or logos (for example, Dana/Spicer or Chrysler branding) can indicate the axle family. If you cannot locate a tag, you can rely on VIN-based decoding or service manuals to confirm the model.
What markings you might find
Axle identification data can appear in several forms, depending on year and model. The most common indicators are a branded identifier on the housing (Dana/Spicer, Chrysler, etc.), and a tag or stamped numbers that denote the axle family and gear ratio. Here's what to look for:
- Brand markings such as “Dana,” “Spicer,” or “Chrysler” on the case or cover
- A small metal data tag attached to the edge of the differential cover listing the axle code and gear ratio
- Stamps directly on the housing or cover with numbers that map to a known axle family and ratio in service literature
Even if a tag is missing or illegible, the combination of the axle family (Dana/Chrysler) and the gear ratio can be verified via the VIN decode or by checking the dealer documentation for your specific build.
How to verify the exact model and gear ratio
Once you have the branding or a tag, you can confirm the exact model and gear ratio by cross-referencing with the VIN and the vehicle’s original build data. If you don’t have access to the build sheet, a Dodge/Chrysler dealer or a reputable parts database can perform a VIN-based axle decode and identify the correct gear ratio and axle model for your exact vehicle configuration.
- Use the VIN to pull the original axle option from a dealer or a trusted online decoder
- Match the axle code to the corresponding model (e.g., 9.25", 11.5", etc.) and the gear ratio
- Verify with the factory service manual or a dealership quote if you are planning work that depends on exact specs
In cases where the data tag is missing or unreadable, you can still determine a close match by counting ring gear teeth and pinion teeth, or by inspecting the differential internals for known design features associated with particular axle families. This method is best used with guidance from a manual or a professional.
Where to get help and resources
If you’re unsure, contact a Dodge or Ram dealer, use official Mopar VIN decoding tools, or consult trusted automotive databases and forums that maintain axle-code references for Dodge vehicles. Local shops specializing in drivetrain work can also identify the differential by comparing it with known models.
Summary
Identifying a Dodge differential centers on locating the axle housing, reading any tags or markings, and cross-checking with your VIN/build data to confirm the exact model and gear ratio. When in doubt, use dealer resources or reputable online databases to verify the axle family (such as Chrysler’s 9.25-inch rear, or 11.5-inch rear in heavier-duty models) and the specific gear ratio for your vehicle’s configuration. Accurate identification is essential for repairs, parts compatibility, and maintenance planning.
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.
How do I know if I have a 3.73 or 4.10 gear?
And since we live in the day and age of 2025. Uh if you're curious. You can easily. Google you know uh the number of teeth on a ring gear.
How do you tell what type of differential you have?
The most accurate differential identification is provided by the bottom line of the tag number or axle tube stamp.
How do I know what differential my Dodge has?
If the ID tag or stamp is missing or unreadable, differentials can be identified by the number of cover bolts, the distinctive shape of the cover, the number of ring gear bolts, and ring gear diameter. They can also be identified by whether the center section is an integral or dropout design.
