Sigma 24-70mm EX f/2.8 and Nikon D40x

I have the Sigma 24-70mm EX f/2.8 with a Nikon mount and I want to get the new D40x from Nikon but the D40x can only do autofocus with AF-S type lenses because it does not have a motor built into the body. I'm guessing the 24-70mm will not do autofocus on the D40x because the sigma has an AF-D mount not AF-S, but then again, people say it has a noisy motor so I would assume there is a motor built on to the lens in which case it might work with the D40x. Anybody know for sure?

Sigma line that has HSM designation will only focus on D40x. 24-70mm EX f/2.8 has gear mechanism not an independent motor, so in response to your inquiry, it will not autofocus on D40x. Hope this help, but then again, maybe try it and it might will.