Dynatrac Free-Spin™ Kit 2005-2014 Ford F-250 and F-350 with DynaLoc™ Hubs for SRW and DRWThe Dynatrac Free Spin Heavy Duty Hub Conversion Kit for 2005 2014 Ford F 250 and F 350 Super Duty trucks is designed replace the factory unit bearings with fixed spindles for superior strength, and smooth performance. This kit fits both single rear wheel (SRW) and dual rear wheel (DRW) trucks. This kit includes DynaLoc locking hubs, providing improved locking hub function, greater strength and a shorter profile for better clearance that reduces the