hi all thanx for all the input.

well after very carfully tear down (again) and rebuild ive noticed a HUGE longditudinal crack right through the chassis !!!

yep that will do it !!!

so got a new one and cant wait to see how much better it is... kinda hope its been like that for a while and has been causing probs for ages...
that way i should see a HUGE improvment

many thanx again

tony