I have a 2008 Z51 with manual trans. The car currently has ~11,500 miles on it. I have a shake/vibration in the shifter when in first gear (stock shifter), but no other gear. It appears to be feedback from the trans. Its had the shake as far back as I can remember. Is this normal? Does it have something to do with the gearing in the Z51 trans? Do other z51 owners have a similar experience?