I have now operated a few different Gravely tractors with the 30" deck. And mine it the roughest one to get to engage. It's actually quite violent! The crashing sound of gears, and it often times kills the engine.
Is there an adjustment? Why is mine so rough to engage while others I've messed with are easier? I do shift the PTO between low and high to try to get it "out of gear" while engaging. But it's still rough.