OTC Tools OTC 7028 Clutch Adjusting Wrench. For Spicer-built Heavy-Duty Clutches. This easy-to-use clutch adjusting wrench will solve the difficult, time-consuming job of internal adjustment of Spicer angle-spring and multiple lever clutches found on nearly 50% of all heavy-duty trucks. Until now, a pry bar or other makeshift method was used and often resulted in damage to parts, poor job performance and excessive downtime. .