Almost all tracks are tensioned by pumping grease into a piston. The grease fitting is typically located behind a cover plate in the center of the undercarriage. This extends the piston and stretches the tracks. (You let grease out of the fitting to reduce tension on the tracks.) Your owner’s manual will give you specs on how to measure track tension. Follow them religiously. Grease is cheap, but improper tension can work the engine and drivetrain harder than necessary and/or accelerate wear on the undercarriage.
More Maintenance/Management tips from “How to Do Everything Better”