I've got a 2005 Nissan Primastar. I'm having problems with the 6 speed gearbox. The gearstick jumps out of 3rd and 4th gears and is making a loud tapping noise. Is there a temporary fix that would get me through the next 4 days until I can get a new gearbox? Any help would be appriciated.

digs, April 2012