CK76,
Welcome to the forums fellow-Tennessean!!! Have you checked and made sure none of your blades ar compromised(bent, warped, etc.)??? I don't know of anything specific that could be causing the ridge, but would suggest that you carefully level the deck to see if that helps. My Gravely has instructions in the manual and most recommend setting each side of the deck's height adjustment for the outer blade tips when facing "sideways" to the same height and then point the blades where the tips are facing forward and adjust where the front blade tips are 1/8 inch lower than the rear tips. My Gravely also states that you can level the deck where the rear blade tips are lower than the front blade tips(referred to as "heeling the deck") and that this gives a better quality cut, but requires more engine power. If it were me and the blades were OK and leveling the deck didn't help, I'd try leveling the deck with the "heeling the deck" setting just to see if that fixed it. Your JD deck leveling instructions may differ from that so go by your user manual. Aside from that cut problem you seem to like your JD. I looked at the 655 last fall, but I was turned off by the 9gauge stamped deck. I got my Gravely Pro-Turn 52" Commercial with a lifetime warranty 7gauge fabricated deck for about the same out-the-door price as the Z655.
