Steering Box Problems

Hi all just have a strange problem with my 71 T3 steering box.
Basicly when leaving my car park at work I have to heave on the steering wheel a bit to get the car out of the tight parking bays. Then I go straight onto the freeway and the steering is all over the place. The wheel will drop left about a quarter of a turn without affecting the front wheels but when moved right it moves the wheels as it should. As you can imagin in windy conditions this gets a bit scarry at 110km/hr.
My mechanic recons the worm drive in the box is worn eaven though this steering box is only 2years old, but it is a Brazillian box.
Is my mechanic right and dose anyone know wheir I can get a German steering box from to hope rectify this problem.
Cheers Nige:thumb

Could the steering box not be centred correctly. And then when the box is adjusted ur adjusting one side more than the other?

Their is an adjustment - or should be. Undo the lock nut, tighten the screw a lettle at time, get it right and then retighten the lock nut. Then again it could be completely different to mine and just be a throw away item - like everything else thats new 😠.