Eaton Performance differentials (including Eaton ELocker, Eaton ELocker4, Eaton Posi, Detroit Truetrac, and Detroit Locker) are warranted for one year against manufacturer defects. The full warranty document can be found here.
While many people do use the Detroit Locker during everyday street use, the Detroit Locker is a very aggressive traction aiding differential, initially developed for off-highway, heavy-duty applications. Eaton also makes many applications for on-highway, heavy-duty trucks.
In the 1960’s, the Detroit Locker became a factory option in some Detroit based OEM muscle cars. While most drivers of street cars will find the aggressive engagement of the Detroit Locker objectionable, drag racers enjoy the auto-locking functionality the differential delivers. The Detroit Locker allows drag racing vehicles to differentiate when turning corners, while offering strength comparable to a full spool.
Detroit Lockers have a very high “strength density”, thanks to continual process innovation, advanced metallurgy, and ultramodern machining methods. All Detroit Locker designs are intended to handle more torque (power) than the axle shafts they drive. Horsepower has no influence on the differential. Most Detroit Locker failures are the result of axle shaft breakage causing reaction energy to “back-drive” the internals at a high rate of rotation speed.
The more relevant concern is how much torque each axle shaft can transmit. Fully locking differentials deliver up to 100% of the driveline torque through a single axle shaft. Open, limited-slip, and non-fully locking differentials transmit less torque – often in the range of 50-70%. This is an important point when upgrading a vehicle from a “standard” differential to a fully locking differential such as a Detroit Locker.
“Soft Locker” versions of the Eaton Detroit Locker / NoSPIN products were introduced in the market several years ago, but not on all models. The function of the Soft Locker is to use a spring generated preload between the side gears of the differential to generate a rotational resistance (dampening). The purpose is to dampen the reengagement action of the Detroit Locker, enhancing the drive feel when used on highway. This preload will cause the units to “feel” as if they have reduced internal lash due to the resistance to rotate, but preload does not influence actual lash.
The internal Belleville style springs and wear disks used in the Soft Locker designs are not required for proper function of the differential. Soft Locker models are identified by the inclusion of "SL" in the model number. For example, 225SL58C.