BMW 5 Series gearbox whine - does the DMF need replacing?

I would like to ask for advice concerning a drivetrain issue I've been having with a BMW F10 520d manual. The car was purchased as an approved used from a BMW dealer with a two year warranty with 35k miles on the clock. Two months into ownership the car developed a rattling and whining noise from the gearbox area and there was also significant juddering when setting off. The sound was similar to that from a turbo when releasing the accelerator, but lower and longer.

BMW replaced the gearbox at their cost due to an internal gearbox fault. BMW confirmed that the clutch was only 30 per cent worn, which is about right for the mileage. The symptoms disappeared for a few months once the gearbox was replaced. A few months and a few thousand miles later the very same symptoms have returned. This will now be the third major repair to the BMW approved used car in less than 10 months of ownership.

A dive into various forums has thrown up topics including worn/failed engine mounts, dual mass flywheel issues (I’m not sure if this is included in the gearbox replacement), throw out bearings and clutch delay valve problems for the juddering. Is there any other likely diagnosis?

Asked on 5 December 2016 by CMH

Answered by Honest John
All of those you found on the forums. The DMF would not have been routinely replaced because it is not part of the gearbox. It sits between the engine and the clutch and its purpose is to protect 1st, 2nd and 3rd gears from too much torque. But that is a separate issue from an internal fault with the transmission, though I guess that the internal fault might have had a consequential effect on the DMF.
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