How do you identify the differential on a Dodge rear end?

To identify the differential on a Dodge rear end, start by locating any identification tag or stamped codes on the axle housing and cross-referencing them with Mopar/Dana axle guides. Dodge and Ram vehicles have used several axle families over the years, including Dana 44 and 60, Chrysler/Mopar 8.25 and 8.75, and modern All‑American Manufacturing (AAM) units such as 9.25/10.5 in newer models.

Where to look for identification marks

Markings are usually easiest to read when you know where to look. The most reliable identifiers come from the tag and the stamping around the housing. Before you inspect the axle, prepare by cleaning the area around the differential cover and tag.

• Axle tag: Some Dodge axles carry a metal tag attached to the housing that lists the model family (for example, D60 or 8.75) and the gear ratio. If present, this tag is your fastest route to identification.


• Differential cover markings: The cover near the fill hole may be stamped or engraved with the axle model and/or gear ratio. A clean, close look can reveal a code that corresponds to a particular axle family.


• Housing casting numbers: On the side of the axle housing or near the third member, casting numbers can identify the axle family. You’ll need to cross-reference these numbers with an axle identification guide or parts database.


• Other markings and date stamps: Some units include date codes or additional alphanumeric codes on the housing or tag that help narrow the year and configuration (e.g., limited-slip, locker, or open diff).

The presence or absence of a removable center section, the number of bolts on the differential cover, and distinctive housing shapes can also offer clues, though they should be confirmed with a code or tag when possible.

Why markings matter

Identification codes determine compatibility for parts like gears, carriers, and lockers. Misidentifying the axle can lead to incorrect gear ratios or incompatible parts, so verify with a reliable cross-reference once you have a code or tag in hand.

How to read the codes and verify the axle family

Once you locate the codes, use a cross-reference approach to confirm the exact axle family and gear ratio. The steps below help you read and verify what you’ve found.

• Identify the model or code block: Look for explicit labels such as D44, D60, 8.25, 8.75, 9.25, or AAM followed by a number. These indicate the axle family or a close approximation.


• Match the gear ratio: The ratio is usually stamped or listed on the tag. If the ratio isn’t visible, you can count the ring gear teeth and drive-count method to calculate it, though this is more involved and should be done with the cover removed only if you’re equipped to do so safely.


• Check for a locking mechanism: Some axles indicate a limited-slip or positive-locking diff in the codes or through visible internal parts (e.g., a clutch-type limited-slip inside the carrier). If the data tag mentions “L.S.” or similar, it’s a clue toward the diff type.


• Cross-reference with documentation: Use the observed codes with a Mopar axle identification chart, a Dana identification guide, or a VIN-specific axle lookup to confirm the exact model and configuration for your vehicle.

If you cannot read the tag or the numbers have worn away, rely on the combination of casting numbers, bolt patterns, and approximate structural features, then verify with official manuals or a dealership/parts database.

Common Dodge rear axle families and distinguishing features

Over the years, Dodge and Ram trucks have employed several axle families. The following overview offers a practical framework to help you narrow down the possibilities, but always confirm with the exact codes you find on your unit.

• Chrysler/Mopar 8.75 and 8.25: Classic Mopar rear axles used in many mid-1990s through early-2000s trucks and SUVs. They are typically identified by a clearly stamped model or ratio on the housing or cover and often feature a deeper center section with a substantial ring gear relative to some lighter axles. Gear ratios commonly vary widely by configuration.


• Dana 44 and Dana 60: Dana axles used in older Dodges and Jeeps. The Dana 60 is heavier and built for higher load capacity, while the Dana 44 is lighter. Distinguishing features include housing shape, the presence of a removable third member on certain versions, and specific cover bolt patterns and flange designs.


• All‑American Manufacturing (AAM) units: In later-model Rams, Mopar sometimes uses AAM-branded assemblies (e.g., 9.25", 10.5", 11.5" variants). These often have a distinct identification code (AAM) on the tag or housing and may exhibit different casing shapes and bolt patterns compared with classic Dana/Mopar units.

Understanding the exact axle family helps when ordering parts, diagnosing issues, or planning modifications. If you’re unsure, consult the vehicle’s build sheet, a parts catalog, or an experienced technician who can verify the axle family from the observed codes.

What to do if the markings are damaged or unavailable

When tags are damaged or removed, you can still gain a reliable identification by combining several methods. Start by measuring and comparing structural cues, then seek cross-reference data from reputable sources. If you’re doing major work like gear swaps or locker installation, it’s wise to remove the differential cover to inspect the carrier and count teeth, noting the gear ratio and any distinctive internal features. If in doubt, contact a Dodge/ram dealership or a professional shop with your VIN and they can typically look up the exact axle specifications for your chassis.

Summary

Identifying a Dodge rear-end differential involves locating and reading axle markings, tags, and casting numbers, then cross-referencing with Mopar/Dana axle guides. Key families you may encounter include Dana 44/60, Mopar 8.25/8.75, and modern AAM units used in newer Rams. Start with the tag or cover markings, confirm the gear ratio, and note any locking or limited-slip features. When in doubt, corroborate markings with official manuals or a knowledgeable technician to ensure correct identification for parts, maintenance, or upgrades.

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.

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 I tell what rear end I have?

You can identify your rear differential by checking for a factory-installed ID tag on the differential cover or axle tube, or by using visual characteristics like the number of bolts on the cover, the shape of the cover, the diameter of the ring gear, and whether it is an integral or dropout design. If all else fails, you can use your vehicle's VIN or the axle code on the driver's side door jamb, and a mechanical inspection of the axle's behavior when a wheel is spun can help determine if it's an open or limited-slip differential. 
Method 1: Check for tags and codes

• Vehicle information sticker: Look for a sticker in the driver's side door jamb or on the vehicle's door for an axle code. You can look up this code online to find the factory specifications, notes the Ford support page. 
• Differential cover tag: Look for a small metal tag bolted to the differential cover, usually under one of the bolts. It may have a gear ratio code stamped on it, like "410" for 4.10 gears, and sometimes a "L" for a limited-slip differential, explains this YouTube video. 
• Axle tube stamp: Some vehicles have a stamp directly on the axle housing itself, notes BigMackTrucks.com. 

Method 2: Visual and physical inspection

• Number of cover bolts: Most differentials can be identified by the number of bolts on the differential cover, commonly 10, 12, or 14 bolts. 
• Cover and housing shape: Note the shape of the cover and whether the differential has an integrated housing or a dropout style where the entire assembly is removed from the front. 
• Ring gear size: Once the cover is removed, you can measure the diameter of the ring gear from tooth tip to tooth tip. 
• Axle shaft and spline count: You can count the number of splines (the raised teeth) at the end of the axle shaft. You can also measure the shaft length, which differs for semi-float vs. full-float axles, notes this YouTube video. 

Method 3: Test the differential type 

• Open differential: Jack up the rear of the vehicle so both rear wheels are off the ground. Put the transmission in neutral and spin one rear wheel. If the opposite wheel spins in the opposite direction, it's an open differential.
• Limited-slip or posi-traction: If both wheels spin in the same direction, it is a limited-slip (or "posi") differential. 

Method 4: If all else fails

• Consult the dealer or a workshop: The Ford support page suggests contacting the dealer or visiting a professional workshop. 
• Owner's manual: The owner's manual may list the axle specifications or code. 

How do you identify a Mopar 8 3 4 rear end?

You can identify a Mopar 8 3/4 rear end by looking for the three-digit case number cast into the center section, which will be a 741, 742, or 489. The easiest visual identifiers are the large cast number (7, 4, or 2) on the driver's side of the center housing, a large, tapered pinion on the 489 case, or a straight pinion with a step on the 741 case.
 
This video explains how to identify Mopar 8-3/4" center sections and the different types of carriers: 41sMostly Old PartsYouTube · Apr 14, 2021
By case number

• 741 Case: Has a straight pinion with a step, which is its weakest point. It came in A-body cars and is best suited for automatic transmissions. It may have a large "X" cast on the driver's side. 
• 742 Case: Stronger than the 741, it eliminates the pinion step. It may have a large "2" cast on the driver's side. 
• 489 Case: The strongest of the three, featuring a large, tapered pinion. It is the basis for most aftermarket cases and may have a large "9" cast on the driver's side. 

By visual features

• Pinion: The 489 case has a large, tapered pinion, while the 741 has a straight one with a step. The 742 case has a straight pinion without a step. 
• Casting numbers: In addition to the three-digit case number, you can find the date the casting was made in an elongated oval below the part number on the case itself. 
• Limited-slip carriers: If your rear end has a limited-slip carrier, it can be identified by the presence of a "Suregrip" stamp. You can differentiate between clutch and cone-type carriers by looking for the extra set of bolts inside the ring gear bolts (cone type) or the absence of them (clutch type). 

You can watch this video to learn more about Mopar A-body 8-and-three-quarter inch axles: 1mMotalesYouTube · Jun 25, 2024