Detroit Locker FAQ’s

What kind of oil should I use? Can I use synthetic? Do I need friction additive/modifier? A quality petroleum/mineral based oil works best in the Detroit Locker units. We do not recommend synthetic oil. Friction additive/modifier is not required.

Can I use the stock bearings? In most cases the Detroit Lockers work with the factory (stock) bearings. The exceptions are: 10 bolt 8.5\8.6 GM axles, the “Performance” Dana 35 & 44 and GM12 bolt with 35 spline axles. No other “special” setup is required.

What kind of break-in is required? The Detroit Lockers do not require any break in.

When does a Detroit Locker lock? The Detroit Locker is locked up 100% in a straight line or if you are spinning. The unit unlocks in a turn for the wheel that is turning the fastest.

When I step on and off the gas pedal, I hear the unit make a “clunking” noise. Why? Because Detroit Lockers have “backlash” or “slack” between the drive and driven teeth and you will hear this in everyday use going through corners and when going from drive mode to coast mode. Also with the vehicle on the ground and the transmission in neutral you will have 1\4 to 1\3rd of a turn of lash in the driveshaft, this is completely normal.

Can I run a Detroit Locker on the street? Many people do use the Detroit Locker during everyday street use. The Detroit Locker is a very aggressive differential, so you will hear it and feel it everyday on the street. Eaton makes many applications for trucks that spend most of their lives on the road. (In the late 60’s, some Ford cars had the Detroit Locker as a factory option.)

How much horsepower and torque will the Detroit Locker take? There are many factors to consider when determining if a specific differential will last in your vehicle. Horsepower and torque are important factors. However, the weight of the car, tire height/width, the terrain and suspension are all important things to take into consideration. For example, a setup that uses street tires will live longer because both tires will break loose and spin before any real strain is put on the unit. But as the tire gets wider, the stress on the unit increases because the traction is greater. When in doubt, the best bet is to call us with your specific application and driving conditions. But also keep in mind that the Detroit Locker is the strongest unit sold today and has been for many years.
Can the Detroit Locker be used in the front axles? Yes they can, but you must have lock out hubs and they MUST be unlocked for on- road driving because of steering issues.

Can the Detroit Locker be repaired? Yes they can. Should you need to repair a Detroit Locker parts can be purchased from any of our dealers. Call Eaton Customer Service so we can provide a blow up of the unit that shows all the part numbers and help you find out exactly what part numbers you need to purchase. At that time we can even recommend a company to buy the parts from.

What is the warranty? The Detroit Locker unit is covered for one year from date of purchase against defects in materials and workmanship. The unit is not covered if the failure of another part (axle shaft or ring & pinion) damages the unit.