The much-awaited Gearbox oil change is here. This was overdue even according to the manual it was overdue and in the words of ZF ” Oil level too low = malfunction” and we were getting malfunction so before the gearbox become a massive metal paperweight it was time to change the oil. Due to the current situation, we have only been able to complete half the change as it is needed to run the bus and warm the oil and gearbox up.