Center Steering Arm Straight Bore Inspection and Salvage Procedure for Off-Highway Trucks {4305} Caterpillar

Off-Highway Truck/Tractor

All

Introduction

Table 1

Revision	Summary of Changes in REHS2110
13	Added note to summary.
12	Added 770G and 772G.
11	Corrected part number in Table 12 and dimensions in Table 18.

© 2016 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law.

Information contained in this document is considered Caterpillar: Confidential Yellow.

This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS Web) interface.

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Important Safety Information

Illustration 1	g02139237

Follow all safety warnings. Most accidents that involve product operation, maintenance, or repair are caused by failure to observe safety warnings. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. Personnel must be properly trained to perform maintenance, repair, or operate any machine. Safety precautions and warnings are provided this instruction and on Caterpillar products. These warnings should be observed before performing any procedures. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are not all inclusive.

The hazards are identified by the “Safety Alert Symbol” which is followed by a “Signal Word” such as “DANGER”, “WARNING” or “CAUTION”. The “WARNING” Safety Alert Symbol is shown in Illustration 1.

Illustration 2	g00008666

This safety alert symbol means:

Pay Attention!

Become Alert!

Your Safety is Involved.

The message that appears under the safety alert symbol explains the hazard.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Cat dealer for replacement manuals. Proper care is your responsibility.

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Personal injury or death can result from not following the proper procedures. To avoid the possibility of injury or death, follow the established procedure.

Summary

The center steering arm straight bore on off-highway trucks can be worn beyond the manufacturing tolerance. This Special Instruction will describe the inspection of the center steering arm straight bore and inspection of the pin. This Special Instruction will also describe the reconditioning of the center steering arm straight bore. Never install a part that is not reusable. Before you install a used part or reconditioned part, correct any conditions that may have caused the original wear.

Note: Steering arms should be visually inspected for cracks prior to reconditioning or reuse. If any defects are found during visual inspection, it should be considered not reusable.

Service Letters and Technical Information Bulletins

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NOTICE
The most recent Service Letters and Technical Information Bulletins that are related to this component shall be reviewed before beginning work. Often Service Letters and Technical Information Bulletins contain upgrades in repair procedures, parts, and safety information that pertain to the parts or components being repaired.

References

Table 2

References
Model	Disassembly and Assembly	Systems Operation/Testing and Adjusting
768B, 768C, 769, 769B, 769C, 769D, 771D	SENR1561	SENR1553
770, 770G, 772, 772G	RENR8273	RENR8268
771C, 772B, 773B, 775B, 776, 776B, 776C, 776C, 776D, 777, 777B, 777C, 777D	SENR5671	SENR6892
773D, 773E 773F, 773G, 775D, 775E, 775F, 775G	RENR8286	RENR8292
776D, 777D, 777F, 777G	RENR3365	RENR3322
784B, 784C, 785, 785B, 785C	SENR4020	SENR4012
785	SENR4020	SENR4012
785B	SENR5678	SENR6309
785C	SENR1500	SENR1492
785D	KENR8192	KENR9701
789	SENR3404	SENR3432
789B	SENR5687	SENR6329
789C	SENR1534	SENR1526
789D	UENR1074	UENR1069
793	SENR4917	SENR4909
793B	SENR5692	SENR6338
793C	SENR1463	SENR1452
793D	RENR8332	RENR8336
793F	UENR1142	UENR2220
797	RENR2037	RENR2609
797B	RENR2588	RENR2579
797F	KENR8382	KENR8734

Recommended Maintenance Interval

Caterpillar recommends inspection of the center steering arm straight bore and pin at the same time as the planned component rebuild for the steering cylinder and steering arm mounting studs. The recommended interval for normal conditions is between 12,000 and 15,000 hours of operation. Refer to SEBF8271 Salvage of Tapered Steering Bores. The interval may be sooner for severe applications.

Tooling and Equipment

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NOTICE
Failure to follow the recommended procedure or the specified tooling that is required for the procedure could result in damage to components. To avoid component damage, follow the recommended procedure using the recommended tools.

Table 3

Required Tools and Equipment 768B, 768C, 769, 769B, 769C, 769D, 770, 770G, 771C, 771D, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
135-5258	Spacer	2
4D-7781, 8X-6730	Sleeve Bearing	2
4D-7779	Lock	1
1B-4367, 6C-3281	Bolt	2
8X-6731	Shim (1 mm Thick)	(1)
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	Use as many shims as needed.

Table 4

Required Tools and Equipment 776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
9D-2737, 8X-6729	Sleeve Bearing	2
9D-2895, 8X-6857, 135-5260	Lock	1
0S-1627, 0S-1756, 251-5715	Bolt	2
135-5259	Spacer	2
323-1841	Shim (0.5 mm Thick)	(1)
8W-5396	Shim (1 mm Thick)	(1)
323-2303	Shim (1.067 mm Thick)	(1)
331-4079	Shim (1.5 mm Thick)	(1)
331-4080	Shim (1.9 mm Thick)	(1)
331-4085	Shim (2.5 mm Thick)	(1)
331-4082	Shim (3.175 mm Thick)	(1)
331-4083	Shim (3.5 mm Thick)	(1)
331-4084	Shim (4 mm Thick)	(1)
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	Use as many shims as needed.

Table 5

Required Tools and Equipment 785, 785B, 785C, 785D
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
8X-6729	Sleeve Bearing	2
8X-6857, 135-5260	Lock	1
0S-1627, 0S-1756, 251-5715	Bolt	2
135-5259	Spacer	2
323-1841	Shim (0.5 mm Thick)	(1)
8W-5396	Shim (1 mm Thick)	(1)
323-2303	Shim (1.067 mm Thick)	(1)
331-4079	Shim (1.5 mm Thick)	(1)
331-4080	Shim (1.9 mm Thick)	(1)
331-4085	Shim (2.5 mm Thick)	(1)
331-4082	Shim (3.175 mm Thick)	(1)
331-4083	Shim (3.5 mm Thick)	(1)
331-4084	Shim (4 mm Thick)	(1)
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-
-	Inside Micrometer	-
-	Heavy Grease	-

(1)	Use as many shims as needed.

Table 6

Required Tools and Equipment 789, 789B, 789C, 789D
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
9D-2737 (1), 8X-6729	Sleeve Bearing	2
9D-2895(1), 8X-6857, 135-5260	Lock	1
0S-1627, 0S-1756, 251-5715	Bolt	2
135-5259	Spacer	2
323-1841	Shim (0.5 mm Thick)	(2)
8W-5396	Shim (1 mm Thick)	(2)
323-2303	Shim (1.067 mm Thick)	(2)
331-4079	Shim (1.5 mm Thick)	(2)
331-4080	Shim (1.9 mm Thick)	(2)
331-4085	Shim (2.5 mm Thick)	(2)
331-4082	Shim (3.175 mm Thick)	(2)
331-4083	Shim (3.5 mm Thick)	(2)
331-4084	Shim (4 mm Thick)	(2)
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	789
(2)	Use as many shims as needed.

Table 7

Required Tools and Equipment 793, 793B, 793C, 793D, 793F
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
8X-6729	Sleeve Bearing	2
135-5260(1), 201-4759	Lock	1
201-4758	Shim Pack	(2)
8T-0070, 8T-0656	Bolt	2
8T-3282	Washer	2
135-5259	Spacer	2
323-1841	Shim (0.5 mm Thick)	(2)
8W-5396	Shim (1 mm Thick)	(2)
323-2303	Shim (1.067 mm Thick)	(2)
331-4079	Shim (1.5 mm Thick)	(2)
331-4080	Shim (1.9 mm Thick)	(2)
331-4085	Shim (2.5 mm Thick)	(2)
331-4082	Shim (3.175 mm Thick)	(2)
331-4083	Shim (3.5 mm Thick)	(2)
331-4084	Shim (4 mm Thick)	(2)
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	793, 793B
(2)	Use as many shims as needed.

Table 8

Required Tools and Equipment 797
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
8X-6729	Sleeve Bearing	2
201-4758	Shim Pack	(1)
135-5259	Spacer	2
8W-5396	Shim (1 mm Thick)	(1)
323-1841	Shim (0.5 mm Thick)	(1)
8W-5396	Shim (1 mm Thick)	(1)
323-2303	Shim (1.067 mm Thick)	(1)
331-4079	Shim (1.5 mm Thick)	(1)
331-4080	Shim (1.9 mm Thick)	(1)
331-4085	Shim (2.5 mm Thick)	(1)
331-4082	Shim (3.175 mm Thick)	(1)
331-4083	Shim (3.5 mm Thick)	(1)
331-4084	Shim (4 mm Thick)	(1)
201-4759	Lock	1
8T-0070	Bolt	2
8T-3282	Washer	2
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	Use as many shims as needed.

Table 9

Required Tools and Equipment 797B
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
5J-8775, 241-3384	Thrust Washer	2
256-6147, 331-1001	Sleeve Bearing	4
201-4758	Shim Pack	(1)
135-5259	Spacer	2
323-1841	Shim (0.5 mm Thick)	(1)
8W-5396	Shim (1 mm Thick)	(1)
323-2303	Shim (1.067 mm Thick)	(1)
331-4079	Shim (1.5 mm Thick)	(1)
331-4080	Shim (1.9 mm Thick)	(1)
331-4085	Shim (2.5 mm Thick)	(1)
331-4082	Shim (3.175 mm Thick)	(1)
331-4083	Shim (3.5 mm Thick)	(1)
331-4084	Shim (4 mm Thick)	(1)
201-4759	Lock	1
239-2206	Bolt	2
8T-3282	Washer	2
239-2213	Lock	1
8M-6393	Retaining Ring	2
293-0372	Block	1
6V-8397	Seal O-ring	2
9X-6032	Bolt	3
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	Use as many shims as needed.

Table 10

Required Tools and Equipment 797F
Part Number	Part Description	Qty
9A-1593	Comparison Gauge	1
7F-7836	Screw	1
6V-1934	Seal O-Ring	2
332-7424	Bearing	1
332-7425	Bearing	2
332-7431	Shim	(1)
332-7428	Plate	2
473-8688 or 473-8689	Inside Micrometer Set 2-12 inch	1
	Inside Micrometer Set 50-300 mm	1
-	Heavy Grease	-

(1)	Use as many shims as needed.

Cleaning Recommendations

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Personal injury can result when using cleaner solvents. To help prevent personal injury, follow the instructions and warnings on the cleaner solvent container before using.

• Before you inspect a part, clean the part thoroughly to remove all debris, paint, and oil.

• Use a proper lifting device to prevent damage to the part. Also, use a proper lifting device to provide safety to the operator when you lift the part.

• During cleaning, do not damage machined surfaces.

• Use pressurized air to dry parts.

• Put hydraulic oil on all machined surfaces to prevent rust or corrosion if inspection is not done immediately after cleaning. Carefully store the parts in a clean container.

Inspection Procedures

Illustration 3	g01064998
(1) Steering support (2) Pin (3) Bolt (4) Steering arm

Table 11

Approximate Center Steering Arm Weights
768B, 768C, 769, 769B, 769C, 769D, 771D	32 kg (71 lb)
770, 770G, 772, 772G	34 kg (75 lb)
771C, 772B, 773B, 775B, 777D	61 kg (135 lb)
776, 776B, 776C, 776C, 776D, 777, 777B, 777C	68 kg (150 lb)
773D, 773E 773F, 773G, 775D, 775E, 775F, 775G	31 kg (69 lb)
776D, 777D, 777F, 777G	59 kg (130 lb)
784B, 785, 785B	81 kg (179 lb)
784C, 785C	115 kg (254 lb)
785D	115 kg (253 lb)
789, 789B	95 kg (209 lb)
789C	43 kg (94 lb)
789D	90 kg (198 lb)
793, 793B	163 kg (360 lb)
793C	165 kg (364 lb)
793D	181 kg (399 lb)
793F
797, 797B	100 kg (221 lb)
797F	289 kg (638 lb)

Center Steering Arm Straight Bore Inspection

Illustration 4	g01065852
Center Steering Arm Straight Bore Measurement

Measuring the Bores

Refer to Table 2 for the proper Disassembly and Assembly Procedure.

1. Measure (A1), (A2), and (A3) at three equally spaced locations near the top of the bore. Refer to Illustration 4 for the measurement locations of the bore. Record the measurements in Table 20.

2. Measure (B1), (B2), and (B3) at three equally spaced locations near the center of the bore. Refer to Illustration 4 for the measurement locations of the bore. Record the measurements in Table 20.

3. Measure (C1), (C2), and (C3) at three equally spaced locations near the bottom of the bore. Refer to Illustration 4 for the measurement locations of the bore. Record the measurements in Table 20.

Table 12

Sales Model	Part Number for Center Arm	Inside Bore Diameter of Center Arm
768B, 768C, 769, 769B, 769C, 769D, 771C, 771D	2G-3205, 6D-1597, 8X-6690, 135-5261	50.85 ± 0.02 mm (2.002 ± 0.0008 inch)
770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	2G-0507, 7D-2884, 8X-6627, 135-5282, 135-5263
776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G	8X-6785, 9D-2277, 135-5265	76.25 ± 0.03 mm (3.002 ± 0.001 inch)
784B, 784C, 785, 785B, 785C, 785D	5T-8728, 8X-6818, 135-5267
789	5T-5730
789, 789B, 789C, 789D	8X-6819, 135-5269
793, 793B, 793C, 793D, 793F	8X-0973, 135-5271, 207-7321
797, 797B	192-5691
797	149-0921	88.90 ± 0.03 mm (3.500 ± 0.001 inch)
797B	293-8689, 396-8975	95.26 ± 0.03 mm (3.750 ± 0.001 inch)
797F	332-7421	133.00 ± 0.03 mm (5.236 ± 0.001 inch)

Center Steering Arm Straight Bore Support Inspection

Illustration 5	g01057743
Center Steering Arm Straight Bore Support

Measuring the Bores

1. Measure the inside diameter of the top bearing bore at three equally spaced locations. Refer to Illustration 5 for the measurement locations of the top bore on the support.

2. Record the measurements in Table 21 under the Top Bore (A), (B), and (C).

3. Measure the inside diameter of the bottom bearing bore at three equally spaced locations. Refer to Illustration 5 for the measurement locations of the bottom bore on the support.

4. Record the measurements in Table 21 under the Bottom Bore (A), (B), and (C).

5. If 4D-7781 8X-6731 9D-2737 8X-6729 256-6147 331-1001 332-7425 Sleeve Bearings are worn or the bearings are damaged, then replace the bearings.

6. If the bore exceeds more than the allowable tolerance in Table 13 or before performing any weld operation on the steering support call the Dealer Solution Network.

Table 13

Top Bore Diameter of Center Arm Support
Sales Model	Inside Bore Diameter of Center Arm Support
768B, 768C, 769, 769B, 769C, 769D, 770, 770G, 771C, 771D, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	60.338 ± 0.025 mm (2.3755 ± 0.001 inch)
776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G, 784B, 784C, 785, 785B, 785C, 785D, 789, 789B, 789C, 789D, 793, 793B, 793C, 793D, 793F, 797, 797B	95.26 ± 0.025 mm (3.750 ± 0.001 inch)
797F	133.00 ± 0.03 mm (5.236 ± 0.001 inch)
Bottom Bore Diameter of Center Arm Support
Sales Model	Inside Bore Diameter of Center Arm Support
768B, 768C, 769, 769B, 769C, 769D, 770, 770G, 771C, 771D, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	60.338 ± 0.025 mm (2.3755 ± 0.001 inch)
776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G, 784B, 784C, 785, 785B, 785C, 785D, 789, 789B, 789C, 789D, 793, 793B, 793C, 793D, 793F, 797, 797B	95.26 ± 0.025 mm (3.750 ± 0.001 inch)
797F	133.00 ± 0.03 mm (5.236 ± 0.001 inch)

Pin Inspection

Measuring the Pin

1. Inspect the pin for damage and measure the outside diameter of the pin at three locations. Measure three equally spaced locations near one end of the pin.

2. Record the measurements in Table 22 under the headings (A1), (A2), and (A3).

3. Measure three equally spaced locations near the center of the pin.

4. Record the measurements in Table 22 under the headings (B1), (B2), and (B3).

5. Measure three equally spaced locations at the other end of the pin.

6. Record the measurements in Table 22 under the headings (C1), (C2), and (C3).

7. If the pin is damaged or the pin is worn beyond the allowable tolerance, then replace the pin.

Table 14

Sales Model	Part Number for Pin	Outside Diameter of Pin
768B, 768C, 769, 769B, 769C, 769D, 770, 771C, 771D, 772, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	5D-1857, 7D-8922, 339-1123	50.795 ± 0.013 mm (1.9998 ± 0.0005 inch)
776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G, 784B, 784C, 785, 785B, 785C, 785D, 793, 793B, 793C, 793D, 793F, 797, 797B	9D-2896, 8X-1847, 8X-1834, 256-6145	76.068 ± 0.013 mm (2.9948 ± 0.0005 inch)
797B	331-1000	79.044 ± 0.013 mm (3.1120 ± 0.0005 inch)
797F	332-7423	109.85 ± 0.013 mm (4.325 ± 0.0005 inch)

Salvage Procedures

Center Steering Arm Straight Bore Preparation for the Sleeve

Table 15

Sales Model	Part Number for Center Arm	Cut Width of Center Arm	Steel Lock
768B, 768C, 769, 769B, 769C, 769D, 771C, 771D	2G-3205, 6D-1597, 8X-6690	6.35 ± 0.50 mm (0.250 ± 0.02 inch)	4D-7779
	135-5261	8.00 ± 0.5 mm (0.315 ± 0.02 inch)
770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	2G-0507, 7D-2884, 8X-6627	6.35 ± 0.50 mm (0.250 ± 0.02 inch)
	135-5282, 135-5263	8.00 ± 0.5 mm (0.315 ± 0.02 inch)
776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G	8X-6785, 9D-2277, 135-5265		9D-2895, 8X-6857, 135-5260
784B, 784C, 785, 785B, 785C, 785D	5T-8728, 8X-6818, 135-5267
789	5T-5730
789, 789B, 789C, 789D	8X-6819, 135-5269
793, 793B, 793C, 793D, 793F	8X-0973, 135-5271, 207-7321		135-5260, 201-4759 (1)
797	149-0921
797, 797B	192-5691

(1)	The steel spacer is similar to the 201-4758 Shim Pack and can be created using the 201-4759 Lock and as few shims as possible from the 201-4758 Shim Pack

1. Secure the center arm cut width to the dimension in Table 15 by fabricating a steel spacer to the thickness specified. To achieve the width, the steel lock for each of the center arms can be used as a spacer along with the fabricated steel spacer

2. Install the steel spacer in the center arm cut and install the two bolts. Refer to Table 2 in the proper Testing and Adjusting Procedure for the bolt torque values

   • 768B, 768C, 769, 769B, 769C, 769D, 770, 770G, 771C, 771D, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G use 1B-4367 Bolts, or 6C-3281 Bolts.

   • 776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G, 785, 785B, 785C, 785D, 789, 789B, 789C, 789D use 0S-1627 Bolts, 0S-1756 Bolts, or 251-5715 Bolts.

   • 793, 797 use 8T-0070 Bolts, or 8T-0656 Bolts

   • 797B use 239-2206 Bolts.

3. Weld the bottom face and counterbore with an AWS A5.5 4130 electrode.
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   Table 16

   Sales Model	Part Number for Center Arm	Dimension of Bottom Face Surface
   768B, 768C, 769, 769B, 769C, 769D, 771C, 771D	2G-3205, 6D-1597	29.46 mm (1.160 inch)
   	8X-6690, 135-5261	22.10 mm (0.870 inch)
   770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	2G-0507, 7D-2884	29.46 mm (1.160 inch)
   	8X-6627, 135-5282, 135-5263	22.10 mm (0.870 inch)
   776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G	9D-2277	28.45 mm (1.120 inch)
   	8X-6785, 135-5265	22.20 mm (0.874 inch)
   784B, 784C, 785, 785B, 785C, 785D	5T-8728	26.00 mm (1.024 inch)
   	8X-6818, 135-5267	19.75 mm (0.778 inch)
   789	5T-5730	48.50 mm (1.909 inch)
   789, 789B, 789C, 789D	8X-6819	23.25 mm (0.915 inch)
   	135-5269	48.50 mm (1.909 inch)
   793, 793B, 793C, 793D, 793F	8X-0973, 135-5271, 207-7321
   797	149-0921
   797, 797B	192-5691

4. Machine the bottom face to a smooth, flat "F" surface finish, refer to Table 16 for dimensions. This is done to maintain the dimension from the nearest bolt hole. The bottom face is within 0.13 mm (0.005 inch) perpendicular to the pin bore.
   Show/hide table

   Table 17

   Sales Model	Part Number for Center Arm	Top of Center Arm Diameter of Machined Counter Bore	Depth of Counter Bore
   768B, 768C, 769, 769B, 769C, 769D, 771C, 771D	2G-3205, 6D-1597	94.00 mm (3.701 inch)	6.35 ± 0.50 mm (0.250 ± 0.02 inch)
   	8X-6690, 135-5261	101.00 mm (3.976 inch)
   770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	2G-0507, 7D-2884	94.00 mm (3.701 inch)
   	8X-6627, 135-5282, 135-5263	101.00 mm (3.976 inch)
   776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G	9D-2277	118.00 mm (4.646 inch)
   	8X-6785, 135-5265	150.00 mm (5.906 inch)
   784B, 784C, 785, 785B, 785C, 785D	5T-8728
   	8X-6818, 135-5267
   789	5T-5730
   789, 789B, 789C, 789D	8X-6819
   	135-5269
   793, 793B, 793C, 793D, 793F	8X-0973, 135-5271, 207-7321	160.00 mm (6.299 inch)
   797	149-0921
   797, 797B	192-5691

5. Machine the counter bore to a "F" surface finish, refer to Table 17 for the diameter and depth. The counter bore should maintain the face of the sleeve and should be parallel within 0.13 mm (0.005 inch) to the bottom face.
   Show/hide table

   Table 18

   Sales Model	Part Number for Center Arm	Machined Bore Diameter of Center Arm
   768B, 768C, 769, 769B, 769C, 769D, 771C, 771D	2G-3205, 6D-1597, 8X-6690, 135-5261	64.00 ± 0.50 mm (2.520 ± 0.02 inch)
   770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G	2G-0507, 7D-2884, 8X-6627, 135-5282, 135-5263
   776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G	8X-6785, 9D-2277, 135-5265	89.50 ± 0.50 mm (3.524 ± 0.02 inch)
   784B, 784C, 785, 785B, 785C, 785D	5T-8728, 8X-6818, 135-5267
   789	5T-5730
   789, 789B, 789C, 789D	8X-6819, 135-5269
   793, 793B, 793C, 793D, 793F	8X-0973, 135-5271, 207-7321
   797, 797B	192-5691
   797	149-0921	102.15 ± 0.50 mm (4.022 ± 0.02 inch)

6. Machine the center arm bore to the diameter in Table 18.

7. Drill a hole and tap the hole on the same centerline as the center steering arm straight bore saw cut. Refer to Table 19 and Illustration 6 callout (A) and (B) for dimensions and locations.

8. Drill the hole to a diameter of 6.53 mm (0.257 inch) with an "F" drill. Drill the hole to a depth of 28.0 mm (1.10 inch).

9. Tap the hole with a 5/16 - 18 tap. Tap the hole to a depth of 25.0 mm (1.00 inch).

Procedure for Sleeve

Note: All surfaces should be machined to an "F" surface finish.

Note: Use 4140 steel to make the sleeve.

Illustration 6	g01065915

Table 19

Center Steering Arm Straight Bore Dimensions of the Sleeve
	Sales Model 768B, 768C, 769, 769B, 769C, 769D, 771C, 771D		Sales Model 770, 770G, 772, 772G, 773, 773B, 773D, 773E, 773F, 773G, 775B, 775E, 775F, 775G		Sales Model 776, 776B, 776C, 776D, 777, 777B, 777C, 777D, 777F, 777G		Sales Model 784B, 784C, 785, 785B, 785C, 785D
Callout	Center Arm Part Number 2G-3205, 6D-1597	Center Arm Part Number 8X-6690, 135-5261	Center Arm Part Number 2G-0507, 7D-2884, 8X-6627	Center Arm Part Number 135-5282, 135-5263	Center Arm Part Number 9D-2277	Center Arm Part Number 8X-6785, 135-5265	Center Arm Part Number 5T-8728, 8X-6818, 135-5267
A (1)	9.50 mm (0.374 inch)
B	39.50 ± 1 mm (1.555 ± 0.039 inch)	43.00 ± 1 mm (1.693 ± 0.039 inch)	39.50 ± 1 mm (1.555 ± 0.039 inch)	43.00 ± 1 mm (1.693 ± 0.039 inch)	51.50 ± 1 mm (2.028 ± 0.039 inch)	67.50 ± 1 mm (2.657 ± 0.039 inch)
C (2)	50.85 ± 0.02 mm (2.002 ± 0.0008 inch)				76.25 ± 0.03 mm (3.002 ± 0.001 inch)
D	8.35 ± 1 mm (0.329 ± 0.039 inch)	10.00 ± 1 mm (0.394 ± 0.039 inch)	8.35 ± 1 mm (0.329 ± 0.039 inch)	10.00 ± 1 mm (0.394 ± 0.039 inch)
E	94.00 mm (3.701 inch)	101.00 mm (3.976 inch)	94.00 mm (3.701 inch)	101.00 mm (3.976 inch)	118.00 mm (4.646 inch)	150.00 mm (5.906 inch)
F	6.35 ± 0.50 mm (0.250 ± 0.02 inch)
G (2)	64.00 ± 0.50 mm (2.520 ± 0.02 inch)				89.50 ± 0.50 mm (3.524 ± 0.02 inch)
H	65.50 ± 0.50 mm (2.579 ± 0.02 inch)	76.70 ± 0.50 mm (3.020 ± 0.02 inch)	65.50 ± 0.50 mm (2.579 ± 0.02 inch)	76.70 ± 0.50 mm (3.020 ± 0.02 inch)	114.00 ± 0.50 mm (4.488 ± 0.02 inch)	100.00 ± 0.50 mm (3.937 ± 0.02 inch)
Center Steering Arm Straight Bore Dimensions of the Sleeve (continued)
	Sales Model 789	Sales Model 789, 789B, 789C, 789D		Sales Model 793, 793B, 793C, 793D, 793F		Sales Model 797	Sales Model 797, 797B
Callout	Center Arm Part Number 5T-5730	Center Arm Part Number 8X-6819, 135-5269		Center Arm Part Number 8X-0973, 135-5271, 207-7321		Center Arm Part Number 149-0921	Center Arm Part Number 192-5691
A (1)	9.50 mm (0.374 inch)
B	67.50 ± 1 mm (2.657 ± 0.039 inch)			72.50 ± 1 mm (2.854 ± 0.04 inch)
C (2)	76.25 ± 0.03 mm (3.002 ± 0.001 inch)					88.90 ± 0.03 mm (3.50 ± 0.001 inch)	76.25 ± 0.03 mm (3.002 ± 0.001 inch)
D	10.00 ± 1 mm (0.394 ± 0.039 inch)
E	150.00 mm (5.906 inch)			160.00 mm (6.299 inch)
F	6.35 ± 0.50 mm (0.250 ± 0.02 inch)
G (2)	89.50 ± 0.50 mm (3.524 ± 0.02 inch)					102.15 ± 0.50 mm (4.022 ± 0.02 inch)	89.50 ± 0.50 mm (3.524 ± 0.02 inch)
H	146.00 ± 0.50 mm (5.748 ± 0.02 inch)

(1)	The dimension is the diameter of the hole with an 82 degree bevel cut for the screw head of the 7F-7836 Screw.
(2)	The dimension of the diameter before the saw cut of dimension (D).

Illustration 7	g02178820

Machine hole, callout (A) with a bevel so the screw head of the 7F-7836 Screw will be flush with the surface or slightly recessed. Clean the parts and dry the parts before you assemble the sleeve into the bore. Secure the sleeve with a 7F-7836 Screw. Chase the threads with the correct tap. Install the thrust washer / shims around the flange of the sleeve bearing.

Illustration 8	g02178821

Install the bottom thrust washer / shims.

Illustration 9	g02178822

Install the top thrust washer / shims. Use a heavy grease to hold the upper thrust washer / shims in place for assembly purposes.

Illustration 10	g02178823

Install the steering arm. Refer to Table 2 for proper Disassembly and Assembly. Refer to Table 2 for proper Systems Operation and Testing and Adjusting.

Note: Refer to Linkage Group Steering for the latest parts and assembly instructions.

Inspection Forms

Center Steering Arm Straight Bore Inspection Form

Table 20

A1	A2	A3
__________	__________	__________
B1	B2	B3
__________	__________	__________
C1	C2	C3
__________	__________	__________

Center Steering Straight Arm Bore Support Inspection Form

Table 21

	Top Bore	Bottom Bore
A
B
C

Pin Inspection Form

Table 22

A1	A2	A3
__________	__________	__________
B1	B2	B3
__________	__________	__________
C1	C2	C3
__________	__________	__________