I recently purchased a 2006 Freelander TD4 with 25,000 miles on the clock.

When I知 driving on a smooth road in 4th or 5th gear at 50 to 60 miles an hour I have an intermittent problem. I feel a vibration and the gear stick wobbles considerably. As I say this is an intermittent problem & tends to occur when I知 accelerating on an incline in the road. I don稚 think its wheel balancing as the steering wheel is solid.
Any ideas on what it could be?