The kind of oil required is determined by the type of blower used on your grain vac. The easiest way to figure this out is by checking the serial number tag on the blower. Once you have determined what kind of blower you have, you can use this guide to specify the type of gear oil needed.
Dresser Roots and M&D Tuthill are the blowers used on the VacBoss and Handlair line of equipment. The Dresser Roots blower uses ISO-220 synthetic gear lubricant. The Tuthill blower uses an ISO-100 synthetic gear lubricant. Please remember that gear oil is not the same as motor oil. You do not want to use a motor oil of any kind in your grain vac blower. Synthetic gear oil is required by the blower manufacturer, and failure to use the correct lubricant can result in voiding your warranty.
You should always check your manual for complete and proper maintenance of your VacBoss and Handlair grain handling equipment. If you’ve lost your manual, a replacement manual may be purchased by contacting the factory at 800-328-8896.