2006/02/06 Caterpillar

Motor Grader:

24H (S/N: 7KK1-UP)

Service Magazine SEPD0842, 19 June 2006, "An Improved Drawbar Group Uses Larger Bolts and New Guides". Disregard this article. Refer to the replacement article that follows.

ReferencePlease refer to 24H Motor Grader Hydraulic and Steering System Specifications, "Drawbar" for specifications regarding the proper assembly of the drawbar.

ReferencePlease refer to 24H Motor Grader Machine Systems Disassembly and Assembly, "Remove & Install Segment".

ReferencePlease refer to 24H Motor Grader Operation and maintenance Manual, "Circle Clearances - Check/Adjust" for the proper procedures to set the running clearances for the circle.

Description of Change: An improved drawbar group is now used. The improved drawbar uses new bolts, machined shoes, and machined washers. The former bolts were 7/8-9 thread. The new bolts are 1-8 thread. The drawbar assembly has been updated with a larger counterbore in order to accommodate the new bolts. In addition to having a larger cross section, the new bolts use a special torque in order to further improve the clamping force. The new New shims are required to accommodate the larger bolts. New circle guide shoes have an improved surface finish.

Adaptable To: The updated 8X-8985 Drawbar Gp is effective with 24H (S/N: 7KK312-UP). All earlier 24H Motor Graders can be updated.

When the motor graders are in service, the 24 1D-5976 Bolts can loosen. On the loose bolts, the threads can become stripped. The bolts can also fall out of the circle guide shoe. All of the bolts on all of the shoes can fail.

Until the machine is available for the permanent repair, an interim repair can be performed. The dealer can install 24 9R-5264 Bosses and 24 6K-8739 Bolts on the machine. The 6K-8739 Bolts have a longer thread depth than the 1D-5976 Bolts that are the standard fastener on the circle guide shoes.

Refer to "Permanent Repair" in order to perform the permanent repair to the machine. Refer to "Interim Repair" in order to perform the interim repair to the machine.

Permanent Repair

Perform the following procedure in order to perform the permanent repair.

Table 1

Required Parts
Item	Part Number	Description	Qty
1	5F-9338	Bolt	24
2	5D-4661	Hard Washer	24
3	275-0513 (1)	Circle Guide Shoe	8
4	275-0511	Shim	136
5	275-0512	Shim	32
6	117-2244 (2)	Wear Strip	8

( 1 )	Installation of the new 275-0513 Circle Guide Shoe is not mandatory. The part number is provided if the new shoes are desired.
( 2 )	Do not replace the wear strips unless the existing wear strips are worn or damaged.

Table 2

Parts For Removal
Item	Part Number	Description	Qty
6	117-2244 (3)	Wear Strip	8
E	6G-4642	Shim	136
D	6G-4643	Shim	32
C	6G-4173 (3)	Circle Guide Shoe	8
B	7X-0572	Hard Washer	24
A	1D-5976	Bolt	24

( 3 )

These parts may be reused.

Table 3

Required Tools
Item	Part Number	Part Name	Description
T1	NA	Drill Bit	22.50 mm (0.886 inch) diameter (4)
T2	NA	Counterbore	30.5 mm (1.20 inch) diameter
T3	4C-5005	Tap	1 - 8

( 4 )

7/8 is the approximate fractional equivalent.

Illustration 1	g01278703

1. Remove Bolts (A) and Washers (B). Remove Shoes (C), Shims (D), and Shims (E.). Remove Wear Strip (6) .

   Note: Retain Shoes (C) if the shoes will be reused. Discard shims (D) and Shims (E). Inspect Wear Strip (6). Replace the wear strips if the wear strips are worn or damaged.

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Illustration 2	g01242572

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Illustration 3	g01278523
(D1) 22.50 mm (0.89 inch) (D2) 30.5 mm (1.20 inch) (D3) 30.0 mm (1.18 inch)

2. Perform the following operations in order to rework 24 existing holes (G) : increase the diameter of each hole., add a counterbore to each hole. and cut new threads in each hole.

   1. Use Tool (T1) in order to enlarge holes (G) to diameter (D1). Drill the holes completely through the 136-2364 Drawbar .

   2. Use Tool (T2) in order to create a counterbore for each hole (G). The counterbore must be diameter (D2) to depth (D3) from the bottom of the 136-2364 Drawbar .

   3. Use Tool (T3) in order to create the 1-8 threads in 24 holes (G). Ensure that the threads are completely cut through each hole.

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Illustration 4	g01278368

3. Assemble Bolts (1), Washers (2), Shoes (3), Shims (4), Shim (5), and Wear Strip (6). Please refer to Illustration 4.

   Note: Shoes (C) may be reused instead of new Shoes (3) .

4. Ensure that the clearances for the circle are properly adjusted. Refer to Operation and Maintenance Manual, "Circle Clearances - Check/Adjust" for the proper procedures. Tighten Bolts (1) to a torque of 1150 ± 100 N·m (840 ± 75 lb ft).

Interim Repair

Perform the following procedure in order to perform the interim repair.

Table 4

Required Parts
Item	Part Number	Description	Qty
1	6K-8739	Bolts	24
2	9R-5264	Bosses	24

1. Remove the circle guide shoes. Refer to Disassembly and Assembly, SENR1438, "24H Motor Grader Machine System", "Segment - Remove and Install".

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Illustration 5	g01292787

2. Discard the 1D-5976 Bolts. Place one 7X-0525 Hard Washer (3) and one 9R-5264 Boss (2) on each 6K-8739 Bolt (1).

3. Install the three 6K-8739 Bolts on each circle guide shoes. For the proper torque, refer to Disassembly and Assembly, SENR1438, "24H Motor Grader Machine System", "Segment - Remove and Install".

4. Refer to Specifications, SENR1428, "24H Motor Grader Hydraulic and Steering Systems", "Drawbar" for the specification regarding the proper assembly of the drawbar.

5. Refer to Operation and Maintenance Manual, SEBU6907, "24H Motor Grader", "Circle Clearance - Check / Adjust" in order to set the running clearances for the circle.