Does it shift hard in all gears? Cleaning the shift modulator generally helps harsh shifts. You can get just about all info you need by going to tech info, then choose performance and find installing a shift kit. It will explain how to get to the modulator and how to remove it and clean it.
If the problem is the modulator then no, it shouldn't hurt anything, but I would still fix it as soon as possible. The modulator is like a shock absorber. It'* a piston that moves and a spring builds up pressure to engauge the clutches. If that piston can't move or moves tight it will shift harsh. A light sanding of the cylinder walls will make the piston move smoothly.