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 .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Worm Gear Note1. 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!