GENERAL AR 1676896 - Caterpillar

TECHNICAL INFORMATION BULLETIN June 02, 2004
Wheel Loader 988G (BNH1-Up)
(2TW1-Up)
Component Codes 6107-BMSUBJECT: Bearing Replacement for Booms with Worn Surfaces
PROBLEM:
When replacing the A-Pin and B-Pin bearings it is more important to maintain the face-to-face distance of the bearings than the pressed-in depth of the bearings. The pressed-in depth can change if the boom surfaces have been worn by debris or by contact with the loader frame or the bucket. Listed below is the proper method for finding the correct bearing face-to-face dimension.
SOLUTION:
Measure the face-to-face distance of the boom. The nominal dimension is 668 +/-1 mm, as seen in Illustration 1. If this distance is within the tolerance band, then the bearing can be pressed into the nominal 5 mm depth using the service tool. This results in an installed face-to-face bearing width of 658 +/-1 mm. If the dimension is outside the tolerance, perform the calculation in Step 2. This will determine the installed bearing depth that is necessary to maintain the proper face-to-face distance.
In order to determine the proper depth to set the bearing, subtract the desired installed bearing distance (658 +/-1 mm) from the measured boom face width. Divide the result by 2.
EXAMPLE:
Measured boom face width: 664
-658
6
6 / 2 = 3
Press bearing 3mm deep on each side.
Illustrations:
Illustration 1: Face-to-face boom width
Illustration 2: Face-to-face bearing width
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