johngen is correct. Clark uses(d) the 4G64 engine that was made in Korea under a license agreement. This engine required a crankshaft balancing system (lancaster type) to minimize vibrating when matched up to the Clark trans axle. The engines 4G63 & 4G64 used in Mitsubishi/Cat lifts were made at Mitsubishi Motors in Japan and matched to a trans axle made by Mitsubishi Heavy Industries (these engines did have a low speed (near idle speed) vibration issue for a period of time (in the mid 90's). It was still there in April,1996 (my last day to work for MCFA) as far as I can recall.