Mercedes-Benz GL-Class: Information on differential anddifferential locks - Differential lock - Off-road driving systems - Driving and parking - Mercedes-Benz GL-Class Owner's ManualMercedes-Benz GL-Class: Information on differential anddifferential locks

When the vehicle drives around a corner, the wheels on the outside of the bend must cover a greater distance and must therefore turn more rapidly than the wheels on the inside.

The differential, a transmission in the drive train, compensates for these different rotational speeds, making cornering possible.

A differential has the disadvantage that the wheels with the least road grip are driven with the greatest force. An example: a wheel of a driven axle is on a snow-covered surface and therefore does not have any traction. The differential causes this wheel to be subjected to the strongest driving force, as the flow of force takes the path of least resistance. On the other hand, the opposite wheel on this axle, which is located on a firm surface and could therefore make traction possible, does not receive any driving force. 4ETS rectifies this disadvantage and provides good steerability by braking the spinning wheel automatically and therefore channeling more driving force to the wheel that is on a firm surface and that can therefore supply traction.

ESP® and 4ETS are traction systems that are ideally suited for driving on roads and on gentle terrain. The LOW RANGE off-road gear also improves off-road capability.

Difficult terrain conditions require further more extensive measures such as the locking of one or more differentials. Your vehicle is equipped with two differential locks: one (central) differential lock for the transfer case and one differential lock for the rear axle.

Each differential lock can be activated with the selector wheel on the center console.

When the (central) differential for the transfer case is locked, the speed of the front wheels is just as high as the speed of the rear wheels.

If the differential for the rear axle is locked, both rear wheels turn at the same speed, regardless of their individual torques. Please note that activating the differential locks severely restricts the vehicle's steerability.

For your own safety, the safety of others and to prevent damage to your vehicle, the differential locks must not be activated on paved roads. Please note that the function of the differential is absolutely necessary for driving on paved roads and that the differentials must not be locked on paved roads under any circumstances. The steerability of the vehicle would otherwise be lost and steering would no longer be possible.

The differential locks must therefore only be activated off-road and only if activating the other driving systems (4ETS, ESP® and LOW Range off-road gear) is no longer sufficient.

    General notes
    Differential locks are available only in vehicles with the Off-Road Pro engineering package. Your vehicle is equipped with the following: • A differential lock for the transfer box: this ...

    Engaging the differential locks
    Pull away slowly when the differential locks are activated. Function or performance tests may only be performed on a 2-axle dynamometer. If you wish to operate the vehicle on such a dynamomet ...

    See also:

    Useful information
    This Operator's Manual describes all models and all standard and optional equipment of your vehicle available at the time of publication of the Operator's Manual. Country-specific differences are ...

    Removing spots
    Remove tar and oil spots, industrial dust, insects, and tree sap as quickly as possible from the paint surface to avoid lasting damage or staining. Special cleaning products are available at a ...

    Customer Assistance Offices (U.S. and Canada)
    Buick encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail Buick, the letter should be addressed to: United States Buick Customer Ass ...