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Non-FE Discussion Forum / Re: F-250 locking differential
« on: June 25, 2026, 07:55:19 AM »I understand, and thanks for the clarification because I did say it wrong.In your scenario a Detroit Locker would stay locked because of the torque applied from the engine, as it works to move the vehicle, will keep the locker locked.
The differential action of a Detroit Locker only happens when the torque forces are low, otherwise that differential will remain locked due to its ratcheting style design.
A Detroit Locker is locked the vast majority of the time by design because it remains locked until the correct low torque conditions allow it to unlock.
. . . . . . .you do not fully understand the way a Detroit Locker works in a vehicle.... which is pretty common, so you are in a normal place.
I believe you may fall into the same "normal place".
Yes, it 'is' of a geared "ratchet" design, and though it does 'transfer' torque as produced from the engine through to the axle shafts, it isn't "torque" sensing in it's operation, rather it is simply "speed" sensing, maybe add "position" sensitive. Remember it's just a "ratchet" system, where as the ring gear turns the differential housing it's bolted to, the internal gearing doesn't allow either output side gear, and therefore axle, from not turning at least at this speed; but the ratchet feature allows either to turn faster. So, when traversing a turn, as there is distance differential to be covered, the inside wheel will not be allowed to turn slower in the pivoting maneuver, so it will be the outer wheel in the turn that will "unlock" or "ratchet" forward and accelerate, as being pushed, in order to traverse this greater distance within the same period of time. After the vehicle straightens out, then as soon as the gear sets realign, the disengaged axle re-locks-up, due simply to the side-springs who's pressure which was overcome to allow the ratcheting effect push things back into this position.
One may garner the impression of "torque" sensing because in an instance where the unit is unlocked, when enough torque from the engine is applied to cause the one engaged tire to begin to slip, the unit will catch the slower in motion tire (sometimes with an announcement!) in lockup. But this action was not based on torque, other than that which caused one tire to turn at a faster rate than the other, rather solely by the fact that as the one tire lost traction the ring gear (an associated componentry) sped up and the planted tire resisted, at least momentarily.
Now once the two tires are spinning, trowing dirt & mud, the unit generally remains locked to both axles, but again this is solely because neither is allowed to be turning at a rate anything less than that of the ring gear, even if this is faster than the overall vehicle's movement; and though torque is what is causing the tires to spin, the unit doesn't care about torque, it's about speed differentials and positioning relationships.
Scott.
My statement it likely worded poorly because I am trying to explain that the locker can be engaged, disengaged, readily with proper use of the throttle.
No throttle, or very light throttle, and the differential will run open around corners.
Careful application of the throttle and it can be either open, or locked, depending on your throttle application. (this can lead to some of the driving oddities talked about)
A bit too much throttle, which is easy with a diesel (even a marshmallow of a diesel like my old non-turbo version) making max torque around 1,400 rpm, and the locker is locked, even going around tight corners, as long as the throttle is applying enough torque it will stay locked too.
In the end the point is, beyond a little noise and some driving quirks that are easy to deal with and learn, there is no locking differential that will provide more durability, or consistent locking of the drive wheels than a Detroit Locker.


) in lockup. But this action was not based on torque, other than that which caused one tire to turn at a faster rate than the other, rather solely by the fact that as the one tire lost traction the ring gear (an associated componentry) sped up and the planted tire resisted, at least momentarily. 
