Sorry, you should see about how good their guarantee is. A new or properly rebuilt gearset should respond immediately. The up and down movement is to be expected from a high mile used unit, NOT one that has been rebuilt. It isn't very expensive to disassemble, clean and reassemble a chuck if all you do is replace the seals. The hard parts are where the higher cost comes in to play. Firm Feel charged me about $300 fora Stage 3 P/S rebuild, and it is the next thing to Rack and Pinion as far as I am concerned.