The manufacturer of the Hi-Ranger, a truck equipped with a hydraulic bucket, has filed a breach of contract lawsuit against the company that designs and manufacturers sprockets used to keep the platforms stable when lifted into the air.

Terex South Dakota Inc., whose parent company is located in Westport, claims in a 10-page lawsuit filed in U.S. District Court in Bridgeport March 31 that the weldments in many leveling sprockets have failed. Terex claims that when it contacted Wisconsin-based Classic Gears & Machining Inc. to discuss the issue, it was told the defect could not be fixed.