steering wheel and vehicle shakes/wobbles

i've just fitted a set off recip trial 265/70/16's to my disco 1 k (reg) and thought i would go for a test drive and i noticed that at 30mph the steering wheel started to shake a little then at 45+mph the whole disco shakes/wobbles .
the disco has got a 2" lift on rear but standard on front.
i have just taken a set of 235/70/16 of and i had no problem with them at all.Can anyone help me with what to try or what it could be.

all advice much appreciated.

atb lee.

Did you get them balanced ? .

tbh no not yet i got them 2nd hand from another guy who had a disco1,i expected them to vibrate a little if they weren't re-balanced but not as bad as they actually are.

cheers mate.

i feel like a right pleb :doh: now just been out and checked the wheels and none of them have the balancing weights on :frusty: so it might be that thats causing the problem.

atb lee