Tranny shudder?????

[budone]

I will be taking my 05 Silverado Z-71 into the dealer next week. However I was wondering if anyone has experienced what I have. When I first felt it, I thought it was a miss in the engine.

 

When I hit the road and the truck shifts into high gear, it seems the tranny is shuddering (flutters???) , like the computer systems are not sure it should be in high gear or not. This happens from 45-52MPH.

 

Once I am 55MPH or over it smooths out.

 

I can watch the tach at 50 MPH and feel the shudder, the tach will go up maybe 150-200RPM, then it will lower again and the shudder begins again.

 

Oh yeah the truck has less than 2900 miles on it.

 

Thanks

Bill