97 silverado shifting problem

97' 1/2 ton silverado with 160K on it. Works fine when cold. When warm, trany down shifts, speedo goes to 0 and abs light comes on. Manual shifting into 1, 2 or 3 kind of works. Anybody got an idea? :screwy:

You need to fix the speedometer problem.
A good scanner may pick up a code and point to the problem.
Post back codes.
MT

Does the tach and prndl display still work when the speedo quits?