Yes, perfectly normal, the play is supposed to be there for fine tuning the valve timing, do not use "magic metal" as previously suggested.
Special tools are supposedly required to change the belt but they are only useful if the engine has lost it's timing, if you're just changing the belt mark the old belt and pulley wheels, duplicate the marks on the new belt and fit it exactly as the old belt came off.
It perhaps goes without saying but lock the crank and cam shaft before marking or taking the old belt off. There are location holes, one in the cam pulley wheel and one that locates in the flywheel, you'll find this one from under the car, it's just under the starter motor.
When the new belt is on fit the bottom timing cover and tighten the bottom pulley wheel a little, not too much as you'll bend or break your crank locking pin. Once nipped up take the pins out, get a friend to sit in the car with it in gear and his foot on the brake, now tighten the bottom pulley up properly.
Once tight rotate the engine by hand a couple of time then make sure your locking pins for the cam and crank still align correctly, if they don't repeat the above steps.
Lee, January 2013
