My '95 1500 4WD gear selector has become "mushy". There is no longer a "click" when changing from gear to gear. The auto transmission shifts under load as well as when originally purchased. No slippage when driving. Dealer replaced the gear selector and it didn't fix it. On second visit, the dealer tightened the linkage and voila - good. Now 12 months later same problem. Should I replace the linkage? If so, is it a DIY job or dealer job? Any idea of cost? Comments are appreciated.