steering rack problem

[bossman]

could anybody offer any advice on a problem i have with a rocket quickrack, when i turn the steering wheel a sort amount left to right i get a clunck from the rack and the pinion visibly lifts in and out of the rack, rtr have stripped the rack and say everything is ok, i have since adjusted the slipper to a point of vitually locking the rack and it still does it, only done 1700m so i would'nt expect a problem this early.
any advice would be appreciated.
thanks John.