I have recently purchased a 1989 300 TE 4matic and the ASD lamp comes on occassionally and goes out again usually when doing over 50 m.p.h. If the brake pedal is applied momentarilly it puts the lamp out. Sometimes the lamp is bright sometimes its dull.

If the 4 matic test lever under the bonnett is put in position 2 to enable rear wheel drive only the ASD lamp does not illuminate as described above.

The 4 matic light appears to be operating OK as it lights up when the ignition is switched on and goes out when the engine is running and the lever under the bonnett is in position 1.

Sometimes but not always when making full lock parking manovers the rear diff locks up causing the rear end to judder is this normal operation of the limited slip differential ?

The ABS seems to trip in regularly when braking to a halt as there is pedal vibration but the ABS lamp does not illuminate this happens at 5 mph or less. The brakes seem okay otherwise just the fluttter from the pedal as you come to a final standstill.