Pontiac Repair: Traction problem when excelerating, auto parts stores, box auto

Question
We have a 2006 Montana van.  When accellerating from a stop position, the van seems to kick into gear as we are driving,not sure how else to describe it.

Answer
Hi there:

does it shift hard? or bang into gear? More so hot then cold? If so chances are that the transmission pressure control solenoid is going bad. stop by one of the big box auto parts stores and have the van scanned for codes and see what code(S) may be stored and start from there. It's just a guessing game untill you know what the issue may be. codes set are a good starting point as to where to start to look. good luck :-)