Snapper ZTR 48 in deck with 3 blades. I think this mower was built by Country Clipper for Snapper before Snapper started making their own ZTR. Today I put new belt from engine to deck and 3 new blades. Now the new belt flops and the deck is constantly moving back and forth. Any idea what might be wrong? I first thought because the new belt was rolled up it might be caused by the bent places in the belt. Then I thought no more than the bend are it would go away in 10 or 15 min but it didn't. Might put the old belt on tomorrow and see. Also thought about new blades out of balance but decided couldn't be out enough to cause the deck to shake, the deck is heavy