Engine Buzz??

[patch697]

Watcha!
Took "The Brick" on our first highway roll. Wagga to Bathurst to Sydney then home. Real pleased with the fuel consumption (1999 GU 2.8 litre TD) coming back in at 11litres/100k but...had what I would call a very tight vibration which can be felt through the steering wheel, gear stick and even the seats. Feels like a heavy buzz and is more noticeable in the lower gears. I tried coasting with the clutch depressed to see if it is wheels/suspension/sterring and the vibration went when the clutch was depressed. Still pulls fine and powers up the hills etc so I'm just wondering if anybody else has/is experiencing this?
Is it normal or an issue? Cheers in advance - Stump - Rock On!

First pot of call would be to go check your uni joints.

Sounds a bit like one to me.