my wipers have become loose and go too low and too high when in use. think it was caused when it was icy and i knocked the wiper stalk when i was taking my steering lock off before clearing the windscreen.
its really anoying as its banging when it hits the black plastic at the bottom.......anyone know how to fix it???

 

Could be an easy fix, could be a pain. The wipers are on a splined drive from the motor. they are held in place by nuts, under plastic covers, at the base of each wiper arm.

You need to prise out the covers, undo the nuts and reset the wiper blade where it SHOULD be, doing up each nut FIRMLY, and replacing the covers. The arms come off easier if you lift them off the screen to vertical, otherwise their springing makes it hard to get them off the splines
HINT: Start wipers and turn off IGNITION to halt them at the very top of their arc. Then set the driver's side one about 40mm from the outer edge of the screen. You may also be able to see where they go on the screen.

HOWEVER: It might be worth checking the splines. On our Xantia, the same thing happened and the splines on the expensive and difficult to replace drive were knackered, while the ones on the cheap and easy to repair arms were perfect
New drive unit and motor

If yours mare damaged, you can sometimes get away with it by wrapping one layer of aluminium cooking foil round the splined drive BEFORE replacing the arm, then tightening up as above. If it's still loose, it's either new arms or a new drive unit.

 

thanks alcazar. il have a go at it tomoro. its pisin it down jus now. i want to get it done before next weekend when i go to scotland. . . even tho ive had all year to do it.