My Trek Mtn bike came originally with SRAM 400 (7 speed) shifters. I recently purchased a set of SRAM 3.0 (7 speed) shifters. I can not get the new rear derailleur to work properly. I would have thought the new shifters would be compatible. I can shift from the lowest to highest gear, but I skip one gear in between. When I'm on the largest cog, the shifter is on #6 rather than top gear #7. I measured the amount play on both shifters and the new 3.0 shifters have more play than the older 400 shifters. Any help would be appreciated
