Differential and Axle Identification
Accurate Differential Identification is the first and most important step in your differential repair, upgrade or overhaul project. The following information is provided to help you identify the differential you are working on. If in doubt, consult one of our differential experts at (800)510-0950! Professional technical support is available Monday thru Friday from 8am to 5pm Pacific Standard Time.

On this page:  Differential Identification by Tag Number  |  Visual Differential Identification

The most accurate differential identification is provided by the bottom line of the tag number or axle tube stamp. Differential tags can easily be used to identify Dana and Ford differentials.

Differential Identification by Tag Number

Dana Spicer Differential Tags

Dana Spicer Differential Identification Tags

The Bill of Material (BOM) number is used to identify Dana differentials. The BOM will identify the model number, the gear ratio, the type of differential, and all component parts. Traditional BOM’s are 6 digits followed by 1 or 2 digits and start with the numbers 60 or 61. On some tags, the first 2 digits don’t appear on the tag, but they must be used to identify the axle. For instance, you might see 5561-1 for the BOM, but the 60 has been dropped, and one would need to use 605561-1. Later BOM’s may start with the first 3 digits of 200, but these are typically not dropped from the tag.

The BOM may be used with the Dana Expert to identify all aspects of this particular axle. Make sure to select the appropriate Light Duty or Heavy Duty section of The Expert.

Axle Identification

On GM axles made by Dana, the Bill of Material is usually stamped in the right hand tube underneath the spring. These BOM’s normally start with 60, and the first 2 digits are not typically dropped as in some cases with Dana ID tags.

Ford Differential Tags

Ford Differential Identification Tag

Ford differential tags are very straightforward, as indicated above. The Month of Manufacture uses the following format:
A = January, B = February, C = March, etc.


GM RPO Identification Codes


GM Vehicles come with a RPO code tag, usually located in the vehicles glovebox or door jamb. These tags have a wealth of information about your specific vehicle’s equipment and specifications. Read more about GM RPO Axle Identification Codes.


Differential and axle repair parts

For complete listings of the Differential Parts available for your application, click the link above or use the “Find Your Parts” icon located throughout our website. We have a huge parts inventory, and orders placed by 4PM Pacific Standard Time can usually ship out the same day!

Need help identifying your differential or not sure which replacement or performance parts you need? Call our staff of differential experts at (800)510-0950. We’re here to help Monday thru Friday from 8AM to 5PM PST.

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Visual Differential Identification

Without an ID tag, differentials are 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. Dropout differentials are also referred to as 3rd members or pumpkins. The chart below shows various differential covers and 3rd Members.

AAM-9.25" Differential Image of American Axle Manufacturing 10.5" Differential Cover Image of AAM 11.5" GM/Chrysler Differential Image of AMC-Model-20-Differential Cover
AAM 9.25″ Chrysler Front Differential

Go To: AAM 9.25″ Parts

AAM 10.5″ Chrysler Differential

Go To: AAM 10.5″ Parts

AAM 11.5″ GM / Chrysler Differential

Go To: AAM 11.5″ Parts

AMC Model 20 Differential

 Go To:  Model 20 Parts

Image of AMC-Model-35-Differential Cover Image of Chrysler-7.25"-Differential Cover Image of Chrysler-8"-IFS Differential Unit Image of Chrysler-8.25"-Differential Cover
AMC Model 35 Differential

Go To: Model 35 Parts

Chrysler 7.25″ Differential

Go To: Chrysler 7.25″ Parts

Chrysler 8″ IFS Differential

Go To: Chrysler 8″ IFS Parts

Chrysler 8.25″ Differential

Go To: Chrysler 8.25″ Parts

Image of Chrysler-8.75"-Differential Image of Chrysler-9.25"-Differential Image of Dana-28-Differential Housing Image of Dana-30-Differential
Chrysler 8.75″ Third Member

Go To: Chrysler 8.75″ Parts

Chrysler 9.25″ Differential

Go To: Chrysler 9.25″ Parts

Dana 28™ Differential

Go To: Dana 28™ Parts

Dana 30™ Differential

Go To: Dana 30™ Parts

Image of Dana-44-Differential Cover Image of Dana-50-Differential Cover Image of Dana-60-Differential Cover Image of Dana-70-Differential Cover
Dana 44™ Differential

Go To: Dana 44™ Parts

Dana 50™ Differential

Go To: Dana 50™ Parts

Dana 60™ Differential

Go To: Dana 60™ Parts

Dana 70™ Differential

Go To: Dana 70™ Parts

Image of Dana-80-Differential Cover Image of Dana-S110-Third-Member Image of Ford-7.5"-Differential Cover Image of Ford-8"-3rd-Member-Differential
Dana 80™ Differential

Go To: Dana 80™ Parts

Dana S110™ Differential

GoTo: S110/S135 Parts

Ford 7.5″ Differential

Go To: Ford 7.5″ Parts

Ford 8″ 3rd Member

Go To: Ford 8″ Parts

Image of Ford-8.8"-Differential Cover Image of Ford-9-3rd-Member-Differential Image of Ford-9.75"-Differential Cover Omage of Ford-10.25"-10.5"-Differential Cover
Ford 8.8″ Differential

Go To: Ford 8.8″ Parts

Ford 9″ Third Member

Go To: Ford 9″ Parts

Ford 9.75″ Differential

Go To: Ford 9.75″ Parts

Ford 10.25″ & 10.5″ Differential

Go To: Ford 10.25″/10.5″ Parts

Image of GM-55-Passenger-Differential Image of GM-55-Truck-Differential Image of GM-7.25"-IFS-Differential Image of GM-7.5"-Differential
GM ’55 Passenger Differential

Go To: ’55 Passenger Parts

GM ’55 Truck Differential

Go To: GM ’55 Truck Parts

GM 7.25″ IFS Clamshell Differential

Go To: GM 7.25″ IFS Parts

GM 7.5″ / 7.625″ Differential

Go To: GM 7.5″/7.625″ Parts

Image of GM-8"-Differential Image of GM-8.2"-Differential Image of GM-8-2-Buick Olds Pontiac-Differential GM-8.25-IFS-Differential
GM 8″ Differential

Go To: GM 8″ Parts

GM 8.2″ Differential

Go To: GM 8.2″ Parts

GM 8.2″ B.O.P. Differential

Go To: B.O.P. Parts

GM 8.25″ IFS Differential

Go To: 8.25″ IFS Parts

Image of GM-8.5"-Differential Image of GM-8.6"-Differential Image of GM-12-Bolt-Passenger-Differential Cover Image of GM-12-Bolt-Truck-Differential Cover
GM 8.5″ Differential

Go To: GM 8.5″ Parts

GM 8.6″ Differential

Go To: GM 8.6″ Parts

GM 12 Bolt Passenger (8.875″) Differential

12-Bolt Passenger Parts

GM 12 Bolt Truck (8.875″) Differential

Go To: 12-Bolt Truck Parts

Image of GM-9.25-IFS-Clamshell Differential Image of GM-9.5"-14-Bolt-Differential Image of GM-10.5"-14-Bolt-Differential Toyota Differential parts for 7.5
GM 9.25″ IFS Clamshell Differential

Go To: 9.25″ IFS Parts

GM 9.5″ Differential

Go To: GM 9.5″ Parts

GM 10.5″ 14 Bolt Differential

Go To: 14-Bolt Parts

Toyota 7.5″ Early 3rd Member

Go To: 7.5″ Parts

Toyota 7.5" IFS Differential Identification Toyota 7.5" Differential Parts Toyota 8" Differential Parts Toyota 8" V6 Differential Parts
Toyota 7.5″ IFS Front Differential

Go To: Toyota 7.5″ Parts

Toyota 7.5″ IFS Clamshell Differential

Go To: Toyota 7.5″ Part

Toyota 8″ 4-Cyl. 3rd Member Differential

Go To: Toyota 8″ Parts

Toyota 8″ V6 / Turbo 3rd Member Differential

Go To: Toyota 8″ Parts

Tacoma T100 8" Differential Parts Toyota 8" Differential Parts Landcruiser 8" Differential Parts Image of Toyota-Tundra-8-75-Front-Differential
Toyota 8″ Tacoma / T100 3rd Member Differential

Go To: 8” Tacoma ? T100 Parts

Toyota 8″ E-Locker 3rd Member Differential

Go To: 8″ Rear Parts

Toyota 8″ Landcruiser High Pinion 3rd Member

Go To: 8″ Landcruiser Parts

Toyota Landcruiser 8.75″ Reverse IFS Front

Go To: 8.75″ IFS Parts

9.5" Landcruiser Differential Toyota 10.5" Differential Parts
Toyota 9.5″ Landcruiser 3rd Member

Go To: 9.5″ Landcruiser Parts

Toyota 10.5″ 3rd Member Differential


Differential and axle repair parts

Differential Repair Assembly exploded diagrams

Need help identifying Differential Components? Go To: Exploded View Diagrams

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