Hello to All. I have a 1989 250TD Manual. I have only owned it for a few weeks. The problem i have is between 20 to 40MPH, there is a very bad low vibration which resonates through the whole car. It's worse on moderate acceleration or decceleration. There are no shakes or wobbles through wheel or car and above 40 it is fine all the way up to motorway speeds. I have changed the engine mounts and checked gearbox mounts, prop rubbers, u/joint, fluids, wheel bearings and also looked everywhere for metal to metal contact underneath the car. It sounds and feels like the diff or gearbox is the problem but i thought that if that was the case, it would be there all the time at any speed! It's baffling me! Any suggestions are greatly appreciated. Thanks.