1362462 Adjustment Gp Fits Caterpillar ModelsOne New Aftermarket Replacement Hydraulic Track Adjuster (Adjustment Gp) for Caterpillar (Cat) Mini Excavators This hydraulic track adjuster group (Adjustment Gp) is part of the undercarriage track tensioning system on Caterpillar 307 and 308 series mini excavators. Using hydraulic pressure and an internal recoil spring, the adjuster maintains correct track chain tension to protect idlers, rollers, and sprockets from premature wear and to prevent