This kit repairs worn servo pin bores on 5F27E cases. Work for the 4F27E also... This is a stand-alone kit that includes everything you need to repair these cases without a machine shop. All you have to provide is a drill, cutting oil, and a hammer. The kit comes with enough bushings to build transmissions. 100% Satisfaction service-- Professional AND Sincere Service allows you to take no risks to purchase. This kit repairs worn servo pin bores on 5F27E cases. This is a stand-alone kit that includes everything you need to repair these cases without a machine shop. All you have to provide is a drill, cutting oil, and a hammer. The kit comes with enough bushings to build transmissions. Turn the boring reamer with a electric drill in low speed. Don't spin reamers any faster than 500 rpm max. Pound in the bushing with the supplied driver tool and ream the bushing by hand with the supplied small reamer. Very nice tool kit.