How do you tell what type of differential you have?

Determining the type of differential in your vehicle is an important step in maintaining and repairing it. The differential is a crucial component that distributes power from the transmission to the wheels, allowing them to rotate at different speeds when turning. Knowing the specific type of differential can help you choose the right lubricant, replacement parts, and repair procedures. In this article, we'll guide you through the process of identifying the type of differential in your vehicle.

Identifying the Differential Type

There are several common types of differentials, each with its own unique characteristics. The most common types are:

• Open Differential: This is the most basic type of differential, allowing the wheels to rotate at different speeds but providing no additional traction or control.


• Limited-Slip Differential: This differential uses clutches or gears to limit the amount of wheel spin, providing better traction in slippery conditions.


• Locking Differential: Also known as a "locker," this differential can be locked to force both wheels to rotate at the same speed, improving traction in off-road or extreme conditions.


• Torque-Sensing Differential: This differential uses a viscous coupling to sense and respond to wheel slip, automatically adjusting power distribution to the wheels for improved traction.

To determine the type of differential in your vehicle, you can follow these steps:

1. Inspect the Differential Housing: Look for any identifying marks, numbers, or labels on the differential housing that may indicate the type of differential.


2. Check the Differential Cover: Remove the differential cover and inspect the internal components. Look for the presence of clutches, gears, or other features that can help identify the differential type.


3. Consult Your Owner's Manual: Your vehicle's owner's manual may provide information about the specific type of differential installed in your vehicle.


4. Research Your Vehicle Model: Look up information about your vehicle's make, model, and year online or in repair manuals to find the typical differential type used in that model.

If you're still unsure about the type of differential in your vehicle, it's best to consult a professional mechanic or refer to a trusted repair manual for your specific make and model.

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.

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 find out what kind of differential I have?

You can identify your differential by looking for a metal tag with a stamped code on the axle or cover, counting the bolts on the differential cover, or by checking the VIN or owner's manual. If these are not available, you can visually inspect the cover's shape, ring gear size, and type of axle shaft, or perform a manual gear ratio test by rotating a wheel and counting the driveshaft rotations. 
This video explains how to identify your differential by checking the tag and how to perform a manual test by rotating a wheel: 58sChris DukeYouTube · Nov 22, 2016
Method 1: Look for a tag or VIN 

• Tag number: A metal tag is often attached to a cover bolt and has a code stamped on it that indicates the gear ratio and other specifications. You can also find a stamp directly on the axle tube. 
• Vehicle Identification Number (VIN): Some manufacturers include the gear ratio in the VIN. You can use a free online VIN decoder to check for this information. 

Method 2: Visual inspection

• Differential cover: Look at the differential cover for clues. 
  • Bolt count: The number of bolts is often unique to a specific differential type (e.g., 10-bolt, 12-bolt). 
  • Shape: The shape of the cover is also a key identifier. 
  • Axle tube diameter: In some cases, the diameter of the axle tube where it meets the center section can help differentiate between similar axles (e.g., tapered vs. straight). 
• Ring gear: The ring gear is the large gear inside the differential. 
  • Diameter: You can measure the ring gear's diameter from tooth tip to tooth tip once the axle is disassembled. 
  • Bolt count: Count the number of bolts that hold the ring gear in place. 
• Integral vs. dropout: Note whether the center section is integral (part of the main housing) or a dropout design where the entire assembly can be removed from the front. 

This video shows how to identify the differential by visual inspection, including checking the bolt count, ring gear, and axle type: 50sYukon Gear & AxleYouTube · Oct 3, 2017
Method 3: Perform a gear ratio test

• Manual test: With the vehicle jacked up and the parking brake off, put the car in neutral. Mark one of the tires and the driveshaft. Rotate the tire one full revolution and have a friend count how many times the driveshaft spins. The number of driveshaft rotations is your gear ratio. 
• Limited-slip vs. open differential test: Jack up the rear wheels and put the transmission in neutral. Spin one rear wheel by hand. 
  • Open differential: The opposite wheel will spin in the opposite direction. 
  • Limited-slip: The opposite wheel will spin in the same direction. 

This video demonstrates how to test if your car has a limited-slip differential: 1mCatfish MotorsportsYouTube · Jan 11, 2024

What are the 4 types of differentials?

Different types control how much or little power makes it to the wheels. There are four common types of differentials on the market – open, locking, limited-slip and torque-vectoring.