Replacement transmission assembly designed as a direct substitute for worn or damaged original parts. Replaces OEM numbers GT41857, 590100301, and 587086401 and is manufactured to match OEM fit and function for reliable service and straightforward installation. Key benefits Direct replacement for failed or worn transmission components, restoring drive and cutting functionality without modification. Engineered to match OEM specifications for fit and mounting points, reducing installation time and the need for adapters. Durable construction for sustained performance under normal lawn and garden equipment use. Compatible with multiple mower and tractor models, simplifying parts selection for repairs. Main features Function: Complete transmission unit for lawn mower and tractor drive systems. Fit: Dropin replacement engineered to match OEM dimensions and attachment locations. Performance: Designed to restore proper gear engagement, speed control, and power transfer for the listed models. Serviceability: Replaces old or broken transmission units to minimize equipment downtime. Compatibility Compatible with the following transmission models: GT87070 (201406) Engine Transmission, GT87069 (580486201) (201406) Engine Transmission, RS800 (582491201) (590277701) (201712) Transmission, RS800 (590277601) (201712) Transmission, RS800 (590277501) (201712) Transmission. Compatible with the following tractor models: 917203900, 917203911, 917203901, 917250810, 917250811, 917250821, 917250820, 917250842, 917250841, 917203921. Compatible with the following mower models: 936048, 936049, 936073, 936074, 936075, 936076, 936077, 936083, 936084, 936085, 936086, 936089, 936095. Typical use scenarios a failed transmission on a listed tractor to restore forward and reverse drive for seasonal lawn care. Install as a replacement unit on a listed riding mower after leak or gear failure to the machine to reliable operation. Keep as a spare part in a maintenance to quickly service multiple compatible models and reduce customer wait time. Notes Confirm OEM numbers and model compatibility before to ensure correct fit for your equipment. This product is supplied as a replacement transmission assembly and does not include unrelated accessories or fluids.