Eaton Detroit Locker Differential 35 Spline 1.50in Axle Shaft Diameter 4.10 & Down Ratio Dana 60HD
The Eaton Detroit Locker 225SL29B is an automatic locking differential for the Dana 60 with 35-spline, 1.50 in. axle shafts and gear ratios of 4.10 and numerically lower. Truck owners look for it when a Super Duty, Ram or GM 1-ton keeps spinning one tire pulling a trailer up a wet ramp, climbing rocks, or plowing, and the open or worn limited-slip carrier is not getting the job done. It works in either a front or a rear Dana 60 and locks both wheels any time the truck is under power.
The Detroit Locker replaces the open or limited-slip carrier between the ring gear and the axles. Instead of spider gears, it uses spring-loaded driven clutches with coarse teeth that stay engaged when torque is applied, so both 35-spline shafts turn together and each tire gets full drive. In a turn, the outside wheel overruns and its clutch ratchets free, then re-engages as the truck straightens out. Eaton describes it as 100 percent automatic, clutchless and maintenance free, working in both forward and reverse with no driver input. In a Dana 60 that means the axle pulls with both tires whether you are backing a boat up a slick ramp or crawling a ledge.
With one wheel off the ground and the truck in neutral, turn the raised wheel. An open carrier spins the other side the opposite way; a healthy limited-slip resists. Then check two numbers that decide which locker you need: axle spline count and ring and pinion ratio from the axle tag. Our carrier break guide explains why the ratio matters, and the Detroit Locker vs Truetrac comparison helps you decide if a full locker or a gear-type limited-slip suits how you drive. For front-axle wear points, read Dana 60 front axle problems.
Part 225SL29B is listed for the Dana 60 front or rear with 35-spline axles, 1.50 in. shaft diameter, in the 4.10-and-down carrier. The Dana 60 carrier break falls between 4.10 and 4.56: ratios from 3.54 through 4.10 mount on this carrier, while 4.56 and deeper gears need the thick-gear 4.56-up carrier. If you are re-gearing to 4.56 or lower at the same time, this unit will not fit; consider the ELocker4 Dana 60 35-spline 4.56-up instead. Many Dana 60s use 30-spline shafts, so count splines rather than assuming, and send us your axle tag ratio and VIN if you want us to check. Prefer a gear-type limited-slip? The Truetrac for 35-spline Dana 60, 4.10-down covers the same carrier break.
Removing a Dana 60 carrier usually takes a case spreader; our Dana 60 housing spreader keeps the housing within its stretch limit. Move the ring gear onto the locker with clean threads and thread locker, press on new carrier bearings, and recheck backlash and pattern because shim stacks change with a new case. Yukon's setup chart lists Dana 60 ring gear bolts at 110 ft-lb and bearing caps at 80 ft-lb. If bearings are worn, the Dana 60 rear master overhaul kit covers bearings, races and seals. Fill with 75W-90 or 75W-140 gear oil; the Detroit Locker has no clutch packs that need friction modifier. On a front axle, unlocked hubs let the truck steer normally in 2WD, and you will feel the locker push and hear it click in tight turns in 4WD.
| Brand | Eaton |
| Part number | 225SL29B |
| Fits | Eaton Detroit Locker Differential 35 Spline 1.50in Axle Shaft Diameter 4.10 & Down Ratio Dana 60HD |
| Type | Differentials |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. It is the 4.10-and-down carrier, which takes Dana 60 ratios from 3.54 to 4.10. Deeper 4.56-and-up gears are thicker and need a 4.56-up carrier.
Yes. It is listed for Dana 60 front or rear with 35-spline axles. Expect heavier steering and some push in tight turns when the front is engaged in 4WD.
No. It locks through toothed driven clutches, not friction clutch packs, so it runs on plain 75W-90 or 75W-140 gear oil.
Yes. The outside wheel ratchets free in a turn and re-engages as you straighten out, which can make a clicking sound and a light jolt. A loud bang on every turn or a no-lock condition is not normal and should be checked.
Carrier bearings at minimum, plus pinion bearings and a seal if they show wear. A master overhaul kit covers bearings, races, shims and seals in one box.
