Not familiar with JD's, but on most LT/GT's there's a bar that mechanically prevents revolution. Look at your owners manual, should have an "exploded" parts view and see if anything is missing.

The part number for the locator strap is GX22213BLE . It is not unusual for the bearings to fail on the clutch and spin the clutch. My guess is if the old locator isn't loose and appears that the clutch may have damaged it that you need a new clutch.

Those electric clutches tend to be pricey, so if it is indeed dying, it may be a limiting factor. If the genuine J.D. part is a bit rich for your blood, you could check mfg supply or other lawn mower parts houses.

Here's some generic info on electric clutches. Don't know if it'll help, but good to know info.

http://www.messicks.com/Articles/FixingElectricClutch.aspx