Feature 1Part Number: Replacing part numbers are 7170528A, 7170528, 9170528A, 71704449, 71704861, 9170528, 91704861, 91705861. 2Applicable Model: Replacement for Cub Cadet; Replacement for MTD machines; Replacement for TroyBilt Sears Craftsman 4042in snowblowers. 3Dimensions: The outer diameter is approximately 1 7/8 in, the inner diameter is 3/4 in, width 5/8 in, keyway 3/16 in, 20 Teeth. 4Powerful Function: This special worm gear drives the auger shaft and has a key slot in the arbor to fit onto the output shaft using a woodruff key. 5Good Replacement: This is a replacement part manufactured for use with snow throwers. Direct replacement for the old or damaged worm gear.Item Type:Worm GearMaterial: MetalPart Number: 717-0528A, 717-0528, 917-0528A, 717-04449, 717-04861, 917-0528, 917-04861, 917-05861OD: Approx. 1 7/8 inID: Approx. 3/4 inWidth: Approx. 5/8 inKeyway: Approx. 3/16 in, 20 TeethFitment:Replacement forCub CadetReplacement for MTDReplacement forTroy-Bilt SearsCraftsman 40-42in Snowblowers Package List 1 x Worm Gear Note 1. Please double check the part number of your item, matching information is for reference only.2. If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks!