Gear shift becomes difficult/heavy after longer drive.
 

I've noticed on my last two highway trips that after about 20-30 miles of staying in 5th gear, the gear lever becomes sort of 'heavy' feeling and it takes more effort to change gears. This includes both taking it out of gear, moving throughout the gate and getting it back into another gear. Feel is the same whether the car is on or off. After sitting for a while and cooling down, regular feel is restored. Fluid level is fine and all the clutch parts are less than a year old. The only thing different is that I put in an S5 shifter.

:scratch:

May not help but when was the last time your trans fluid has been changed?

Sounds temperature related. Long drive raises transmission temperature, and possibly some parts expand and become harder to slide around, or transmission fluid gets hot and loses its lubricating properties. Maybe both. I'd say change the fluid.

Oh, another thing to check is that you have enough fluid in the shifter housing as well. That area needs good lubrication. Lack of fluid and heat expansion could make the rod harder to slide.

The fluid was changed about a year ago. I'll put some more fluid in the shifter housing, see if that helps. Going to top off the trans sump too.

mine does the same thing. i changed the fluid to royal purple and lucas and its not as bad, BUT i haven't driven a real long distance yet.

Stock shifter?

yep. i have a miata short shifter i want to install, but i want to make sure the trans is going to work fine without it first.