protruding location of bearing race 20 make it a convenient point to apply a wrench to pump housing 12 and the flats 42 are sized to fit such a tool with bolts 14 loosened a wrenching force applied to the flats 42 will translate directly to the off center bearing race 20 to which channel 34 is solidly welded creating a torque on pump housing 12 about its primary axis to twist it within the chamber 16 as pulley 26 orbits around the primary axis of pump housing 12 it changes the tension against belt 28 the shape of neither bearing race 20 nor pump housing 12 need be changed since the flats 42 may be easily stamped into the channel 34 this is a great advantage since both bearing race 20 and pump housing 12 are made of heavier more expensive materials than is channel 34 and each is more easily made in a cylindrical shape as shown variations of the preferred embodiment disclosed could be made without departing from the spirit of the invention more vents holes 32 than just two could be provided since the surrounding continuous nature of channel 34 means that all additional vent holes would be covered not just those that drained under the force of gravity thus channel 34 would be particularly useful as a collector if a singer ring were added to shaft 24 which threw leaked coolant outwardly channel 34 could be stamped without the flats 42 in a.