General Engine Products Inc. assembles diesel engines for the Hummer off-road vehicle. To detect missing bearings, the company had been using a hydraulic test. However, the process was time-consuming and messy. This article explains how a dry test method improved the process.
The hydraulic test measured oil pressure with the crankshaft driven at 30 rpm by a servomotor. Another servomotor turned the oil pump to generate oil pressure. Oil pressure readings were taken at every 90 degrees of crankshaft rotation and compared with set limits.