In Journal Assly, a rubber seal is placed in upper journal housing around the journal shaft. The Rubber Seal does not, per-se, fail on its own quickly. They, however, cuts grooves into the shaft. PF and ash/dust assist this groove formation. The pinch and profile of the seal also contribute to groove formation.

The normal procedure of repairs of such groove formed Journal Shaft is simply to undercut the shaft where grooves have formed, weld fill & machine to size. However, weld deposit being softer than the parent material subsequent groove formation is quicker still.
MTBF thus remained notoriously short.

Continued repetitive repairs as above introduces run-outs in the shaft. Welding also introduces stresses in the shaft resulting in accelerated fatigue failure.

Several procedures were tried to achieve hard and smooth surface on the shaft where the Rubber Seal is in contact with the shaft. Providing a Single Piece Wear Sleeve was an option and tried at several places. But these Single Piece Sleeves have not proved to be successful/ satisfactory
Single Piece Sleeve, necessarily Shrink Fitted, necessitates removal of bearings during first and subsequent replacement fitments, always resulting in damage to seating portion of the Sleeve and the bearings, and often to the bearings themselves. The Single Piece Sleeve has THREE other inherent draw backs. ONE – it tends to rotate around the shaft, TWO – it tends to slip from its position, and THREE – it remains once use and throw type.