OK I messed up. It needs to be 34,59,145, and 40. I have some of it correct. I have the small idler pulley where it needs to be and the belt guide too. I got 2 right and 2 wrong. So Sears is correct on this I read it wrong. I have that spacer which only works with the tensioner spring where it does not belong.
These are the parts for the small idler pulley:
Part # 34
3 (2)
Husqvarna Lawn & Garden Equipment Carriage Bolt 596136101
Part #596136101
Replaces #72110612Info Icon
-----------------------------------------------------
Part # 145
Husqvarna Lawn Mower Idler Pulley 532177968
Part #532177968
Replaces #193197Info Icon
---------------------------------------------------------------
Part #40
Husqvarna Lawn Mower Lock Nut, 3/8-in 532409149
Part #532409149
Replaces #73900600Info Icon
-------------------------------------------------------
#59
Lawn Tractor Belt Keeper 531165901
Part #531165901
Replaces #141043Info Icon