Failure of the Turbocharger Thrust Bearing in a 3508B Locomotive Engine{1052} Caterpillar

Engine:

3508B (S/N: 5PS1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

The thrust bearings inside of the 158-6599 Turbocharger Gp have been failing of engines that are coupled with hydraulic transmissions. The failures have occurred between 800 and 2000 service hours.

Damage to the thrust bearings is due to turbocharger surge caused by excessive engine lugging. The excessive lugging is due to overloading of the engine during transmission shifting.

Solution

To avoid the turbocharger surge, reduce the load on the engine during transmission shifting. Reduce the load in order to limit lugging to a maximum of 10 percent of the engine rated speed during transmission shifting.

For example, for a rated speed of 1800 rpm, limit the reduction of engine speed by lugging to a maximum of 180 rpm.