GUARD GP-BOTTOM 5121044 - Caterpillar

Introduction
Technical Information Bulletin provides instructions for applying new software for Nitrogen Pumper Applications. Refer to the following information for software selection and installation.Problem
Reports of failures of CX35-P800 Petroleum Transmissions used in Nitrogen Pumper Applications with a NOV HydraRig NP1600 quintiplex nitrogen pump. These failures are the result of torsional vibrations generated by the NP1600 pump during certain operations. The torsional vibrations exceed the design capacity of the transmission and cause failure of the input shaft and torsional coupling.Solution
Parts Service Only flash file, 467-4784, has been generated, and is available thru the Service Software Files search in SIS Web. The new software limits the engine and transmission from operating under certain damaging conditions.Software Functionality:If Actual Gear = 4, Lockup Clutch is Engaged and Engine speed is between 1650rpm - 1925 rpm and Engine % Torque >55%, then the engine speed will be commanded to 1625 rpm, and will remain for at least 5 seconds. After 5 second timer expires, If Engine % Torque falls below 45% or Desired Gear changes, then engine speed will return to requested engine speed. If requested engine speed drops below 1625 rpm at any point, the engine will go to requested engine speed.