The Pins for the Sidebar Bend or Break Caterpillar

The Pins for the Sidebar Bend or Break

Usage:

The Pins for the Sidebar Bend or Break

CONFIDENTIAL TIBU3668

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TECHNICAL INFORMATION BULLETIN	August 14, 2002
WHEEL LOADERS	988G (2TW1-Up, BNH1-Up)
	Component Code: 6102, 6817

SUBJECT: THE PINS FOR THE SIDEBAR PROTECTORS BEND OR BREAK

PROBLEM:

Figure 1

Early production buckets of two rock bucket groups, 175-1452 (175-1453 Assembly) and 175-1462 (175-1463 Assembly) have the pinholes for the sidebar protectors out of position. When a 9J-9600 Sidebar Protector is pinned to the sidebar, it does not properly contact the sidebar (figure 1) and the loads imposed on the protector are carried directly to the pins. High loads may cause the pins to bend or break and the protector to fall off.

SOLUTION: All buckets with protector pin problems and all 175-1453 and 175-1463 Bucket Assemblies should be checked for correct fit. Push on the protector towards the sidebar and upward to take pressure off the pins. The pins should be able to move freely. If they are tight, check for clearance between the sidebar and the two contact locations on the protector. Wedges can be added at the ends of the protectors to reduce their allowable translation and rotation.

Fabricate two of the following parts from steel with a minimum Rockwell C35 hardness. All dimensions are shown in millimeters.

Part 1

Part 2

Part 3

Part 4

Add wedges to provide a contact surface for the protectors for when the bucket is digging. Locate Part 1 by sliding it between the top end of the bottom protector and the sidebar until it touches the protector. Clamp the wedge in position. Similarly locate and clamp Part 2 between the bottom end of the top protector and the sidebar. Locate Part 3 by sliding it between the bottom end of the bottom protector and the sidebar until it lifts the protector. Similarly locate Part 4 by sliding it between the top end of the top protector and the sidebar until it lifts the protector. The wedges need to lift the protectors without excessively loading the pins.

Note: Grind the wedges as required to assure that each wedge contacts the protector router along on its entire contact surface and not just at one point.

Tack the wedges in position. Temporarily remove the sidebar protectors and weld 8mm bevel welds on each side of the wedges. Reinstall the protectors. Replace the retention hardware (135-9350 Pins & 114-0359 Retainers) as necessary.

Alternate Solution:

An alternate repair is available can be used with the listed repair procedure or in addition to the listed repair procedure.

Remove the protectors. Select a hardfacing stick electrode which produces a Rockwell C 34-44 hardness. (Use Lincoln Electric MM40, Stoody 1105, McKay Hardalloy 42, Hobart 400, Eutectic Eutectrode N2, etc.) Preheat the sidebars to at least 350oF. Build up the two contact surfaces for each protector by applying hardfacing. Build up the surfaces until they project enough to contact the protectors in their loaded positions and allow the pins to slide through their holes without binding. Allow the welded areas to cool slowly. Reinstall the protectors.