Stihl Oil Pump Worm Gear for 021, 023, 025, MS170-251 Chainsaws 1123 640 7102

Stihl OEM worm gears are a high quality replacement option for your Stihl chainsaws. Worm gears (also known as pinion gears) are one of those wear items that get little attention until they quit working. Like all moving parts, they will eventually give out with prolonged use and need to be replaced, especially when running low quality bar oil or used motor oil. We recommend having a couple of spares around.