We would like to remind you that the rear axle on the models listed above can only be tested on the brake test stand with the front axle stationary under the following conditions:
Speed: < 7 km/h
Maximum duration: 1 min
The test should always be aborted if the instrument cluster displays the message 4MATIC Not Available. This indicates that the temperature in the rear axle is too high.
These conditions cover regular main inspections, in other words the rear axle is not damaged. In order to protect the rear axle, further investigations on the brake test stand (e.g. analyses of brake squeal), in which these conditions cannot be met, must not be performed. Unplugging the electrical connection at the all-wheel drive solenoid valve (Y68/3) for actuating the rear axle will not prevent damage from occurring.