either play in spindle /wiper arm or box behind dash ,you can either unscrew box and turn gear wheel around 180 degrees or pull rack out from motor end stopping just before it comes off gear wheel so that you can reposition gear wheel and feed rack back ,ive found a lot of new parts dont work/fit even some supposedly genuine so worth trying repositioning first
I dunno if it's just cos I'm a tight arse but I usually just rotate the wiper box by 120 degs instead of 180. That gives me 2 more goes out of it. If the wiper box is that badly worn though sometimes 180 is the best bet.
I have a similar problem on mine but I am not sure if I am missing a part. Should there be some type of shim that goes between the spindle on the drive motor and the linkage that connects to the wiper drive cable? See pic below
Withdraw the wiper drive spring, remove the wiper arms, rotate the wiper boxes, re-fit the wiper drive spring, turn wipers on and let em do a cycle and then re-fit wiper arms.
Get him to squirt water whilst testing them, they go further down with the lubrication, all my defenders owned have stuck up further when the window is dry.
I also use some water repel stuff that makes the screen look greasy from the outside, wipers glide better and less friction.
Cheers guys, got it stripped down and it was the bolts that hold the wiper boxes on to the cable had come loose so tightened them up and I am back in business!