Eaton 225SL29B Detroit Locker Dana 60 35-Spline (4.10 & Down) for 1971-25 Truck

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Product Specification:

SKU:EAT225SL29B

MPN: 225SL29B

Weight: 30.0 lb

Inventory: 2

Type: Differentials

Vehicle Fitment

1971-2025 Multiple Makes (Ford, Dodge, Chevy, GMC, Chrysler, Plymouth) Trucks/SUVs with Dana 60, 35-spline, full-float axles, 4WD / F-Series / Super Duty etc.

Fitment Notes

Fits only Dana 60 and Dana 60 HD axles with **35 spline**, **1.50-in axle shaft diameter**
Gear ratio must be **4.10 or numerically lower** (i.e. 4.10 & "down")
Ring gear size required: **9.75 in**
Does not fit C-clip style axles
If installed on front Dana 60, hubs must be unlocked / compatible
1971-2025 beyond 2016 Super Duty fitment is less clearly confirmed in all sources - verify factory axle specs before installation. "Fitment confirmed through 2024. 2025 unconfirmed."

Features

100% automatic locking differential - full lock under load with no driver input
Bullet-proof, heavy-duty design suitable for off-road, towing, and work use :
Designed for both front and rear axles when axle meets spec
Steel carrier construction for durability
Works with 9.75-inch ring gear
Compatible with 1.50 in axle shaft diameter
Carries Eaton's warranty (typically 12 months) against manufacturing defects
Optimal for vehicles upgraded with larger tires or for heavy load/offroad usage

Specifications

Part Number: 225SL29B
Axle Type: Dana 60 / Dana 60 HD
Spline Count: 35 splines
Axle Shaft Diameter: 1.50-inch (full float)
Ring Gear Diameter: 9.75 inches
Gear Ratio: 4.10 & numerically lower (i.e. 4.10, 3.90, etc.)
Position: Can be used front or rear, so long as axle spec matches (front Dana 60 require hub unlock)
Fitment confirmed through 2024. 2025 unconfirmed. (As newer trucks may have different axle designs.)

Included Components

1x Eaton 225SL29B Detroit Locker differential assembly

Product Description

The **Eaton 225SL29B Detroit Locker Differential** is a robust locking differential designed to transform a standard Dana 60 axle into a traction-dominated powerhouse. It delivers full locking in both forward and reverse under load, ensuring both wheels receive equal torque when one loses grip. Used in demanding applications - heavy towing, large off-road tires, or mud, snow, and trail work - this unit maintains control and traction that open differentials simply can't match.

Built to Eaton's engineering standards, this locker is made for Dana 60 axles with 35 spline full-float shafts, fitted to a 9.75-inch ring gear, and matched with gear ratios of 4.10 & down. Because the locker is automatic, no manual locking or electronic control is needed - it engages as slip occurs. For front axle usage, it's essential that hubs are unlockable (non-full-time locked hubs) to prevent driveline binding.

This part is relevant for many classic trucks (Chrysler/Dodge, Chevy, GMC) and more modern Super Duty / heavy-duty Ford trucks so long as their axles meet the specification. Fitment is confirmed through 2024; if you have a 2025 or newer model, check your axle specs (spline count, shaft diameter, ring gear size) to confirm compatibility. Installation typically requires professional differential setup (shimming, bearing preload) to OEM or better torque specs.