tm9-8024 is basic operation and maint.this one is a MUST HAVE,tm9-1819ac is teardown and repair of basic components,only if you need to repair major components,you didnt say what was wrong with tranny,it is a gm hydramatic ,has hi,low built onto rear of trannythe first thing to do isto check the fluid,next,ifit will crank and runcheck the coolant fluid,if truck still wont move READ TM 9-8024,THE VERY NEXT STEPIS CRITICAL,ADJUST ALL LINKAGES PER THE MANUAL,DONT LET ANYONE ELSE TELL YOU DIFFERENT,HI ,LOW ,FRONT WHEEL DRIVE,REVERSE ARE ALL ON SAME SHIFTER,LINKAGE ADJUSTMENT FOR TRANNY AND TRANSFER CASE ALL NEED TO BE DONE AT SAME TIME,2 person job get help,tm9-8025-2 is for the tranny,unless you want to try to repair tranny yourself,NOT RECOMMENDED,you dont need to buy this one,everything you can do on your own is in tm9-8024,this tranny and motor was in m135 m211 trucks,m59 apc,m50 ontos tracked guns,the tranny was in50s era gm cars,just the tranny without the hi low,parts are stillout there and so are tranny repair shops,THE WEAK LINK ON THESE TRANNYS IS HI RANGE REVERSE,DONT USE IT ,ALWAYS USE LOW RANGE IN REVERSE,BEEN THERE AND DONE IT,good luck keep posting,BUY MANUAL AND READ IT