Degradation in oil can lead to judder, noise and a deterioration in gear change quality.
ZF recommends oil and filter changes after 50,000 to 75,000 miles on all 5, 6 & 8 speed automatic gearboxes to ensure optimum performance.
From the factory, a fluid and filter change on this transmission is a very lengthy process. The sump and filter are normally one piece and fitting involves jacking the engine up and unbolting the mounts, plus the removal of the exhaust.
For all vehicles using the ZF 6HP26 automatic transmission – Discovery 3, Discovery 4, Range Rover Sport and Range Rover L322 models.