ONE AFTERMARKET TRACKING ARM THAT FITS FREIGHTLINER AIRLINER II FASII (1990+) SUSPENSIONS PLEASE BE SURE TO VERIFY THAT THIS IS THE CORRECT TRACKING ARM FOR YOUR TRUCK BY MEASUREMENT AND/OR VIN AS FREIGHLINER OFFERS SEVERAL DIFFERENT TRACKING ARMS ON THIS SUSPENSION SAME FIT AS FREIGHTLINER 16-18972-001,16-15632-001, 16-13965-000, 681-326-67-16 TRACKING ROD REPLACES ROD THAT ATTACHES FROM THE TOP CENTER OF THE DRIVE AXLE HOUSING TO THE FRAME ARM HAS RUBBER BUSHINGS ARM IS 23-13/16" (23.81") FROM CENTER OF BUSHING TO CENTER OF BUSHING ONE STRADDLE MOUNT BUSHING IS CLOCKED AT ZERO (STRAIGHT WITH THE ARM) AND THE OTHER STRADDLE MOUNT BUSHING IS CLOCKED AT 35 DEGREES STRADDLE MOUNT BUSHING ARE 4-3/8" CENTER TO CENTER WITH 5/8" BOLT HOLES INTERCHANGES WITH THE FOLLOWING: FREIGHTLINER 16-18972-001 FREIGHTLINER 16-15632-001 FREIGHTLINER 16-13965-000 FREIGHTLINER 681-326-67-16 AUTOMANN - TMR534 DAYTON PARTS - 345-966 RUBBER VERSION OF ATRO - TR46-41972 If you have any questions you can contact us at 1 844 628 9059 between 8am and 5pm Mountain time or come by at 1030 East Commerce Drive, Suite 200, St. George, Utah 84790.