gearbox and body shudder

hi,need some help, my manual td4 has started to shudder on the odd occasion when cold at around 40-50 mph. the gear stick shakes and the shudder seems to start under the gear stick and spreads to body and then steering wheel, got so bad today that I could not see anything in the rear view mirror! had the car up on ramp at local 'butchers' they checked everything underneath and all was good,nothing loose, missing or bent suggested that i make a note of when it happens and accelerating,stopping,etc. it does not do it when i carry heavy loads, seems to only do it once a day and if i stop and turn off then on again it seems to be ok, any ideas wbma.

As the garage says, more info.
What if you accelerate, brake, coast in neutral , slow down.
Does turning off the engine do anything or is it just stopping?

Does it do it at around 2000 RPM, when you are using a very light throttle?

hi, thanks for the reply, if i turn off engine and start again it seems to get rid of the problem for a time, also had two new tyres on front about month ago ,some cheap chinese rubber! done two trips today of about 15 mile each and no vibration , not making any sense. seems to happen at around 2000 rpm and does it slowing down and speeding up .cheers

Stick the new tyres on the back and save transmission damage later on !
May also cure the vibration.

Hi andyfreelandy, thanks for the reply , good idea will try asap, if it works will let you know.