JLG 943-A Telehandler Falling on its face

I have a JLG 943-A and when I shift it into second gear, the thing falls on its face and does not want to move. It moves fine in first gear, but shift into second and it just slows to a crawl and eventually stops. Im at a loss here.. Anyone know where to start looking?

JLG 943-A Telehandler Falling on its face