Any ideas? xj6 sovereign vibrating when reaching 60mph? gear box, diff or other?

 

*Possibly* propshaft related.... but do you know if your wheels are balanced correctly (might be a good idea to get them checked anyway, just to make sure) & that a wheel/wheels has/have not worked loose at all? Also in this vein, have you locked up a wheel or clipped a kerb at all before this started? This may well have 'flat-spotted' a tyre or buckled a wheel (easy done, these are heavy cars), causing these symptoms.

 

I have the same problem.Its coming from the rear of the car.It sounds like a hummmming sound.My car is a 1996 xj6 base sedan.Please reply as quickly as possible....

Thanks.