Sears Lawn Tractor Caster Wheel ( Yellow) 634Z04629-4028 Genuine OEM. This is a Genuine OEM Sears part. This caster wheel (part number 634Z04629-4028) is for lawn tractors. Caster wheel 634Z04629-4028 attaches to the front pivot axle of the lawn tractor. Wear work gloves to protect your hands when installing this part.... - Sears Lawn Tractor Caster Wheel ( Yellow) 634Z04629-4028 Genuine OEM.