RING GEAR THRUST SCREW CLEARANCE ADJUSTMENT REVISED

IN THE INTEREST OF IMPROVED SERVICE LIFE, WE HAVE REVISED OUR RING GEAR THRUST SCREW ADJUSTMENT TO A CLEARANCE OF .025"-.035" (.635MM-.889MM). THIS NEW ADJUSTMENT APPLIES ONLY TO THOSE DRIVE UNITS EQUIPPED WITH A THRUST SCREW, IT DOES NOT APPLY TO DRIVE UNITS EMPLOYING A THRUST BLOCK AND ADJUSTING SCREW ARRANGEMENT, I.E., QAR MODEL (REAR/REAR DRIVE UNIT OF THE SQHP TANDEM AXLE). THIS NEW THRUST SCREW CLEARANCE ADJUSTMENT SUPERSEDES ALL PREVIOUSLY RECOMMENDED ADJUSTMENTS FOR THOSE DRIVE UNIT MODELS AFFECTED. IN CURRENT DRIVE UNIT MODELS, SUCH AS THE "QAR" AND OLDER MODELS THAT EMPLOY A THRUST BLOCK AND ADJUSTING SCREW, THE ADJUSTMENT REMAINS THE SAME, I.E., QAR=.010"-.020" (.254MM-.508MM). USE THE FOLLOWING PROCEDURES FOR ADJUSTMENT. A.INSTALL THE THRUST SCREW AND LOCK NUT INTO SIDE OF DRIVE UNIT CARRIER. THREAD THE THRUST SCREW INWARD UNTIL END OF SCREW CONTACTS THE BACK OF RING GEAR. B.TO ESTABLISH THE CORRECT CLEARANCE ADJUSTMENT OF .025"-.035" (.635MM-.889MM), LOOSEN (BACK OUT) THE ADJUSTING SCREW ONE HALF (1/2) TURN FROM THE RING GEAR. C.SECURE THE THRUST SCREW IN THE ADJUSTED POSITION BY TIGHTENING THE LOCK NUT AGAINST CARRIER 150-190 LB. FT. (203-258 N.M). D.RECHECK THE ADJUSTMENT TO ASSURE A MINIMUM CLEARANCE OF .025" (.635MM). THE ATTACHED AUTOMOTIVE TECH SERVICE AID BULLETIN TSA-2-107* REVISES ROCKWELL'S RING GEAR THRUST SCREW ADJUSTMENT. THE NEW ADJUSTMENT APPLIES ONLY TO THOSE DRIVE UNITS EQUIPPED WITH A THRUST SCREW. *REPRINTED COURTESY OF: ROCKWELL INTERNATIONAL HEAVY VEHICLES COMPONENTS OPERATIONS TROY, MICHIGAN

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