GM-50900 is a bridge and compressor assembly and is used with the GM-50903 Load Gauge to apply various load pressures on clutch pack assemblies for travel checks. The clutch pack is set onto GM-50905 Clutch Air Travel Fixture and the assembly is placed in the counter bore in the bottom plate of GM-50900. The GM-50900 Forcing Screw is turned until the pressure gauge reads the proper load for the clutch pack assembly. This flattens the pack assembly and forces out any air trapped between the discs and backing plates. The GM-8001 Dial Indicator is positioned on the clutch pack input shaft and set to zero. Air at shop pressure is then fed into one of two ports in the GM-50905 depending on the pack to be measured (C45678R or C23468). The travel dimension shown on the dial indicator is checked and compared to the eSI specification. Different clutch pack assemblies require different loads.