Slow down. Without a difflock, your Disco is practically helpless off-road the minute the amount of traction becomes different under each of the wheels. Permanent four wheel drive, yes, but power is routed through a center differential. When you "put" your Jeep in 4wd, the front and rear axles are locked. Your Disco is in 4wd all the time, but neither axle is locked together. This means that theoretically, if one wheel of the four is on ice and the other three are on dry pavement and you are on a steep incline, all the power will go to the one wheel on the ice and you will go nowhere. The diff lock is operating on the center differential only, so when its locked, its the equivelant of the Jeep with 4wd engaged. Maybe you are thinking of axle lockers, like an ARB air locker or a detroit locker, or the type of lockers that come on a new Rubicon. These lock the open differentials at the front and / or rear of the vehicle so the wheels on both sides of the axle are forced to turn. This type of locker may be fitted to a Land Rover, but does not come standard. Searcaigh mentioned the capable Disco II without the diff lock but with ETC and HDC. First of all, it DOES have the same center diff lock as the DI, but the only way to engage it is with a wrench from underneath the vehicle. ETC (traction control) manages slip and directs torque in place of the diff lock. In this way, it technically accomplishes the same thing as center, front, and rear diff locks using the ABS brakes and a computer. The Disco I has no ETC system and needs to have the diff locked in order to be capable. The Disco does have advantages over, like a Jeep, in suspension travel, axle articulation, heavy duty components such as frames, axles, hubs, etc, water capabilities...on and on. Land Rovers and Range Rovers never have used front or rear lockers in the past because with axles locked together halfshafts, diffs, and driveshafts can all get destroyed, plus you can't steer, etc. Land Rover has always relied on ETC since 1992 for the Range Rover and 1999 for the Disco (II). ETC has the advantage of sending torque to the wheel with the most grip, but it won't break anything. However, it is a poor system since it reacts only when grip is lost in the first place. Also, with lots of continuous use, it can overheat and shuts down temporarily. Finally, being electronic, it can fail. Other manufacturers of exceptional 4x4's, do use the diff locks. The Mercedes-Benz G-Class and Unimog can lock all three diffs together. I mentioned the new Wrangler Rubicon, although how hard-core this machine is I don't know...The new Land Rover LR3 (Disco replacement) uses auto-locking center and rear diffs, and the Hummer (H1 & H2) use a combo of diff locks and traction control.
Why doesn't your diff lock work? Can you just not get it engaged? Keep trying to work it in, it will eventually go.
). I am well aware of its caoabilities and shortcomings, but have never taken the disco to the trails (just boaght it two weeks ago). Mine is a 98 w/o functioning diff lock. How much of a difference w and w/o the diff lock, and what are the situations which will cause the faults to reveal themselves?
