Had my Yeti serviced today and despite regular servicing at the correct intervals, it would appear that both driveshaft seals are leaking and the oil is black suggesting internal failure. Any ideas or recommendations for places that rebuild or supply reconditioned gearboxes? I’m in the South East. Also some sense of cost would be great.

Engine oil goes black from carbon, but gearbox oil normally stays clean for years.  I'm not sure I can think of any way in which engine oil could make its way internally to the driveshaft seals.  And it would be rather a coincidence for them both to start leaking at the same time.  Suggest you get a second opinion as to where the black oil is actually coming from. Or, clean everything up as much as possible, go for a run until things are warm and then re-inspect. Any oil from a minor leak will normally cling to the metal surfaces and then drip off at the lowest point.

Probably a mixture of gearbox oil and CV grease. How much leakage are we talking? An ooze or a drip? If the former, wipe off and monitor, if it's not dripping on the road there's nothing to worry about.  Photos would help.

Edited 22 January, 20206 yr by Wino

The only route I can think of for engine oil to get to the inner CVs is via the bell-housing, and involves serious clutch slip!