My 01 Lude is having trouble shifting into 5th gear... It happens about 1 out of every 4 times I go from 4th to 5th.... And it quite often gets stuck in 5th to the point where I have to pull extremely hard to get it to release. It does it more often when cold. Ive also noticed a humming noise only in 4th and 5th gear. I was thinking it was a clutch issue at first but as time goes on it feels more like the tranny or linkage. Anyone have any insight?