Walk behind Blade Runner transmission problem

[drjeff]

Last year changed the v-belt on my Ariens BladeRunner. Followed the instructions and the picture in the manual to the letter however the belt is constantly making contact and even when I let go of the drive handle and there is slack in the cable, the drive is engaged, When I lift up the back of the mower by the handle, the drive wheels are constantly turning and trying to pull the mower backwards with the engine on is nearly impossible. Even with the engine off, pulling the machine backwards is quite difficult with lots of resistance. Had my friend who services lawnmowers look at it and he has no idea. Thinking I should just change the belt again but the one I installed is an exact Ariens replacement.

Any thoughts???

Thanks