I have a 2007 Chevy silverado 1500 and the transmission on it is messing up from second to third. It'll just rev up to high rpms and sometimes I'll press the gass and it'll just rev up and not go anywhere. And it'll also won't go into first or reverse unless I put it into park turn off my truck than turn it on and put it into gear.

SOURCE: 1978 chevy k20 4x4 truck

try checking your vacume lines..

SOURCE: MY TRUCK WILL GO INTO REVERSE BUT NOT INTO DRIVE?

fisrt gear clutch is burned out , if you push the truck with a car up to 30 mph and drop it into drive you will get 2nd and 3rd , but when you stop you have nothing. if first gear clutch burns up you don't get any forward gears.

SOURCE: 2005 chevy silverado 1500, service 4 wheel drive, gears

Sounds like a bent fork in the transfer case. It is a common problem with your truck. The transfer case is a np236. If it just recently started doing this, the rebuild will cost around $800. If the 4wd has been acting up for a while, the planetary will probably need changed, which is another $200.

SOURCE: 2001 chevy silverado 1500 AT shifting problems

My 2001 chevy truck has rough shifting on 2nd and 3rd gear. it seem when the transmission is hot like when I travel over 100 miles or more. it shifts normally otherwise. Thanks

SOURCE: truck won't go in reverse

take it to a transmision shop sounds like a problem with the valve body