The spindle is a vital component of the lawn mower's cutting deck which enables the blades to work smoothly for an even cut. If your mower blades produce weird grinding noises, have a hard time spinning or spin unevenly then you may have a problem with your spindle assembly. Compatible with: 100 Series Riders Since 2006 John Deere 42", 48" & 54" Lawn Mower Decks LA100 LA110 LA115 LA120 LA130 LA140 LA165 X105 X106 X110 X115R X120 X126 X130R X135R X140 X146R X155R X165 X166 X166R D100 D160 102 115 125 135 145 155CI Replacement part number: GY20454, GY20867, GY20962, GY21098, 285-851 This is a compatible replacement part manufactured by AA Ignition. This spindle assembly kit is NOT a genuine OEM part. Vehicle makes and their associated vehicle models and part numbers are used in this listing only to identify the vehicles this spindle assembly kit fits.