Our 2009 2.2 Di-D Outlander regularly jumps out of 2nd gear. Mitsubishi dealer and importer (Netherlands) say they have no idea as to what the cause may be.
Any ideas before we are forced to replace the entire gear box?

 

First i would get underneath and check all bushings and linkages first.

Then check the motor and transmission mounts.

Bad pilot bearing on the flywheel can cause this also, do you hear any metal whining sounds from outside the car???

Last, if all those check out, then the dealer or a good transmission shop should be able to pull the transmission off and split the case to see what the problem is. Best thing about manual transmissions, they are easy to fix, you don't necessarily need a replacement.