Tap here to read more about Caltric Spindle Assembly w/Pulley Blade For Troy-Bilt Z 46 46 Zero-Turn Mower. Premium Quality Replacement Part Spindle Assembly with Blade Pulley & Bolts For Troy-Bilt Models. Z 46 (17BAFACT066) – Troy-Bilt Mustang 46 Zero-Turn Mower (2021). Z 46 (17ARFACT066) – Troy-Bilt Mustang 46 Zero-Turn Mower (2021). Weight: 5 lbs 4 oz.