A narrow profile, variable width stump grinder comprising a stump treatment tool adapted to forcibly grind a stump and a variable width carriage. The carriage comprises a rigid elongated frame and independently driven wheels coupled to the frame by extensible axles or struts. The frame comprises a longitudinal central member terminating in a header supporting the tool and a front tongue adapted to be coupled to a tow vehicle. The retractable struts are oriented generally perpendicularly to the longitudinal axis of the machine. The header comprises a housing defining parallel sleeves oriented perpendicularly to the axis to receive the struts. A hinged stand is pivotally secured to the top of the header to support the treatment tool in a raised position for transport. A linkage interconnecting the struts and a hydraulic cylinder deploys or retracts the struts to widen or narrow the grinder's stance. The linkage comprises an L-shaped crank pivoted to the frame. The major portion of the crank is pivotally coupled to a tie rod connected to the in-board end of the strut. The minor portion is pivotally coupled to the cylinder. Extension of the cylinder pivots the crank relative to the frame and retracts the strut. The linkage and cylinders nest against the frame when the struts are retracted presenting an overall narrow profile.
