STARTING MOTOR GP-AIR 4W5107 - Caterpillar

All Caterpillar Products Equipped With Delco-Remy Electric Starting MotorsDelco-Remy electric starting motors use bushings in the drive end housing, the commutator end frame and the center bearing assembly.
Replacement bushings are available. The bushings must be machined before installation to get the correct clearances between the bushings and the shaft.
Generally, a 0.038 mm to 0.127 mm (.0015" to .0050") clearance is desired for bushings used in the commutator end frame, the drive end housing and the center housing (when equipped with a Bendix friction clutch). Bushings used in the center housing for starting motors equipped with standard Bendix clutches, Dyer drives or over speed clutches must have a clearance of 0.23 mm to 0.33 mm (.009" to .013").
When the bushings are machined, they must be installed even with the surfaces as shown in the Illustrations. The housing or frame in which each bushing is installed, must be in correct alignment with the bore machine. The frame or housing must be in full contact with the alignment surface, and the bushing must be on the same center line as the bore machine shaft.
Information on installation and machine work for the bushing in the drive end housing.
Information on installation and machine work for the bushing in one type of commutator end frame.
Information on installation and machine work for the bushing in a second type of commutator end frame.
Information on installation and machine work for the bushing used in one type of a center housing.
Information on installation and machine work for the bushing used in a second type of center housing.
Information on installation and machine work for the bushing used in a third type of center housing.Where a tangent wick is used, the new bushings must be drilled. The hole must be the same diameter as the wick hole. Put SAE 20 oil on the wick before assembly of the starting motor. If no tangent wick is used, put the bushing in SAE 20 oil before assembly of the starting motor.
The chart which follows has the bushings, their lengths, and their outside and inside diameters.
The information in this article is only for the specific bearings shown in the chart. New bearings of a different design will be available in the future. The new bearings will be made to a finished size at the factory, and they must not be reamed.