Sprockets and Retainers Wear on the Service Brake Groups and the Final Drive Groups and For Certain Motor Graders{4050, 4251, 4267} Caterpillar

Motor Grader:

120M (S/N: B9C760-UP; B9N346-UP; B9W209-UP; D9W1-UP)

12M (S/N: B9F1047-UP; B9R1-176,760-UP)

140M (S/N: B9D3193-UP; B9G1-251,1056-UP; D9G1-208,1001-1166,1168-UP; B9M1078-UP)

14M (S/N: B9J1450-UP; R9J1-130,132-UP)

160M (S/N: B9E530-UP; B9L1-120,506-UP; B9T183-UP; D9T1-UP)

16M (S/N: B9H866-UP; R9H1-UP)

Introduction

ReferenceRefer to Disassembly and Assembly, KENR6419, "Service Brake (Wheel Spindle) - Disassemble ", and the Disassembly and Assembly, KENR6419, "Rear Axle, Differential, and Final Drive - Disassemble" for the proper procedures to be followed when removing the 120M and 12M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, KENR6419, "Service Brake (Wheel Spindle) - Assemble ", and the Disassembly and Assembly, KENR6419, "Rear Axle, Differential, and Final Drive - Assemble" for the proper procedures to be followed when assembling the 120M and 12M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, KENR6425, "Service Brake (Wheel Spindle) - Disassemble", and the Disassembly and Assembly, KENR6425, "Rear Axle, Differential, and Final Drive - Disassemble" for the proper procedures to be followed when removing the 140M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, KENR6425, "Service Brake (Wheel Spindle) - Assemble", and the Disassembly and Assembly, KENR6425, "Rear Axle, Differential, and Final Drive - Assemble" for the proper procedures to be followed when the assembling 140M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, RENR9727, "Service Brake (Wheel Spindle) - Disassemble", and the Disassembly and Assembly, RENR9727, "Rear Axle, Differential, and Final Drive - Disassemble" for the proper procedures to be followed when removing the 160M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, RENR9727, "Service Brake (Wheel Spindle) - Assemble", and the Disassembly and Assembly, RENR9727, "Rear Axle, Differential, and Final Drive - Assemble" for the proper procedures to be followed when the assembling 160M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, RENR8639, "Service Brake (Wheel Spindle) - Disassemble", and the Disassembly and Assembly, RENR8639, "Rear Axle, Differential, and Final Drive - Disassemble" for the proper procedures to be followed when removing the 14M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, RENR8639, "Service Brake (Wheel Spindle) - Assemble", and the Disassembly and Assembly, RENR8639, "Rear Axle, Differential, and Final Drive - Assemble" for the proper procedures to be followed when assembling the 14M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, KENR6019, "Service Brake (Wheel Spindle) - Disassemble", and the Disassembly and Assembly, KENR6019, "Rear Axle, Differential, and Final Drive - Disassemble" for the proper procedures to be followed when removing the 16M sprockets and retainers.

ReferenceRefer to Disassembly and Assembly, KENR6019, "Service Brake (Wheel Spindle) - Assemble", and the Disassembly and Assembly, KENR6019, "Rear Axle, Differential, and Final Drive - Assemble" for the proper procedures to be followed when assembling the 16M sprockets and retainers.

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

There have been some dealer reports of sprocket wear. Wheel and final drive bearings are wearing into the sprockets and retainers. This sprocket wear is found while servicing the brake disc or tandem joint. The following information is a preliminary sprocket wear specification. Dealer feed back is needed to help investigate this concern on sprocket wear. If the parts need to be replaced, then send the parts to Caterpillar per the Send It Back Request.

Solution

When servicing the brake disc or tandem joint bolt spacers, check the wear on the sprocket.

Wheel Group Sprocket Wear - Sprocket to Bearing

Check the Wear on the Sprocket to the Bearing and Retainer

Illustration 1	g02432256
Sprocket wear

Illustration 2	g02471037
Retainer wear

1. Check the wear on the sprocket. If the wear is less than 0.025 mm (0.001 inch), then the parts are OK to use.

2. Reset the preload.

3. If the wear on the sprocket is greater than 0.025 mm (0.001 inch), then reset the preload only if the measured gap is greater than 0.050 mm (0.002 inch).

Check the Wear on the Sprocket to Retainer Wear

1. Check for fretting that is due to spline backlash.

If the wear is excessive, then flip the retainer over, polish the face of the sprocket and reset the bearing preload.

Note: If the bearing preload cannot be set, then replace the worn parts.