4I7338 Track Adjuster Assembly Fits CAT Fits Caterpillar E110B E120B 311 311One New Aftermarket Replacement Track Adjuster Assembly Fits Caterpillar (Fits CAT) Excavators This aftermarket replacement track adjuster assembly Fits Caterpillar compact and mid size excavators in the 300 series and E series lines. The track adjuster is a hydraulic undercarriage component that maintains correct track tension, preventing premature wear on track chains, sprockets, and rollers. The assembly includes a piston, tube, fittings, and seal