Craftsman LT1000 lawn mower,pulled lever on back of mower to go in nuetral to roll.now can't get it to go back in gear

Hi corncob, welcome to AMHD :)

Those levers can be tricky, but if you take your time you will feel a detent position in the lever.

One right before you go into forward, and one before you go into neutral.
I'm thinking, your hitting that detent, and not getting the whole way forward.

I am guessing that you are talking about the pressure release for the hydrostatic transmission.

You will have to make sure that there is nothing obstructing the movement of the linkage. If it is moving OK then there is trouble in the transaxle.