On the bench in our Welshpool workshop this week — what’s left of a Detroit locker out of a small 4WD truck.
Detroit lockers are one of the cleverest mechanical components in a truck. No air. No hydraulics. No electrics. No button in the cab.
How they actually work: springs inside the locker sit either side of the diff centre and read the pressure coming through each axle.
Equal pressure on both rear wheels (straight through soft sand) — locker engages, both wheels drive. Pressure shifts when one wheel needs to spin slower (hard corner) — locker releases that wheel so you can turn. All decided mechanically, every kilometre, with no driver input.
When one fails, it’s a full diff strip-down: new locker, gear pattern checked under paste, bearings preloaded to spec, road test.
If a truck in your fleet is making new noises in the diff or losing drive in soft ground, it’s worth looking at before it ends up in pieces.
Webbie’s Mechanical, Welshpool WA. Perth’s Truck Experts
#TruckMaintenance #FourWheelDrive #DiffRepair #PerthMechanic #WebbiesMechanical