Are you sure it is the valve body and not the solenoids?
What trouble codes are you getting?
Replacement of the valve body involves draining the transmission fluid and removal of the oil pan.
For purchase, either the dealer or transmission repair shops.
March, 4, 2013 AT 8:43 AM
There is a good chance that your input and output speed sensors are bad. Same thing happened to one I worked on and that solved it. They cost around $50 for the pair on eBay.
Valve bodies can be expensive and not easy to replace although I have not done one on this vehicle. Entire transmissions around here cost $300-$500 out of salvage yards, that may be a good alternative also. If you are looking to do the job yourself you could find a self-service junk yard and try pulling a valve body there.