PRODUCT SUPPORT PROGRAM FOR DIRECTIONAL CLUTCH FAILURES ON CERTAIN 12H, 120H, 135H, 140H, 143H, 160H, AND 163H MOTOR GRADERS Caterpillar

PRODUCT SUPPORT PROGRAM FOR DIRECTIONAL CLUTCH FAILURES ON CERTAIN 12H, 120H, 135H, 140H, 143H, 160H, AND 163H MOTOR GRADERS

Usage:

SEBE6880-02

May 14, 1999
(Revised September 2003)
U-126
A-105
AU-90
S-75
H-51
O-115

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*After failure only*	PRODUCT SUPPORT PROGRAM FOR DIRECTIONAL CLUTCH FAILURES ON CERTAIN 12H, 120H, 135H, 140H, 143H, 160H, AND 163H MOTOR GRADERS
3155		PS5642

NOTE: This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS5642" as the Part number and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.

NOTE: This Revised Service Letter replaces the May 14, 1999 (Revised December 1999) Service Letter. A Change was made to the Termination Date.

TERMINATION DATE

May 31, 2004

PROBLEM

The directional clutches can fail due to wear on the clutch hub assembly and the half rings that retain the hub to the shaft on certain 12H, 120H, 135H, 140H, 143H, 160H, and 163H Motor Graders. The wear is caused by the half rings rotating in the shaft groove. A different retention method of the hub assembly can be installed on the directional clutches to prevent wear.

AFFECTED PRODUCT

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Model	Identification Number
12H	2GS1-392
12H	2LR1-294
12H	2WR1-798
12H	4ER1-578
12H	4XM1-2138
12H	5ZM1-297
12H	8MN1-701
120H	2AN1-154
120H	3GR1-81
120H	4MK1-638
120H	5FM1-1666
120H	6NM1-254
120H	6TM1-439
120H	9FN1-539
120H	9YR1-397
135H	3YK1-369
135H	7MM1-248
135H	8WN1-573
140H	2ZK1-4178
140H	3AS1-502
140H	3FR1-195
140H	5HM1-1486
140H	8JM1-294
140H	8KM1-393
140H	9TN1-1009
140H	9ZN1-309
143H	1AL1-678, 680-682
160H	2HS1-390
160H	2FM1-501
160H	3GM1-90
160H	3HR1-10
160H	6WM1-340
160H	9EJ1-735
160H	9JM1-357
163H	5AK1-206

PARTS NEEDED

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Quantity	Part Number	Description
6	5C7423	SCREW
6	9W9905	RING-LOCK
6	6Y1115	RING-HALF
3	1616713	WASHER
3	1717093	HUB AS

ACTION REQUIRED

See the attached procedure.

SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	Caterpillar		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts	Labor Hrs	Parts	Labor Hrs	Parts	Labor Hrs
0-7000 Hours 0-42 Months	100%	25	0	0	0	0
7001-10,000 Hours 43-84 Months	33.3 %	12.5	0	0	50%	12.5
NOTE: This is a 25-hour job.
NOTE: $405 will be allowed to machine the two shaft assemblies (6Y1885 & 6Y2424). If the choice is made to purchase new shaft assemblies (171-7091 Forward shaft assembly & 171-7095 Reverse/Second shaft assembly), the cost of the new shaft assemblies will not be reimbursed. ONLY the cost to machine the shafts will be reimbursed.

PARTS DISPOSITION

Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

Attach. (1-Rework Procedure)

REWORK PROCEDURE

If it is determined a directional clutch has failed or has wear on the 9W9901 Hub Assembly and the 6Y1115 Half Rings, all the directional clutches (FWD HIGH #1, FWD LOW #2 and REV #3) should be reworked using the following procedure. 1. Refer to the Service Manual as necessary.

2. Remove the transmission from the machine.

3. Disassemble the transmission far enough to remove the REVERSE/SECOND shaft assembly (6Y2302 Clutch Group) and the FORWARD shaft assembly (6Y2301 Clutch Group).

4. Disassemble both shaft assemblies and remove all clutch components.

5. The two shaft assemblies will have to be machined to accept the new parts. See the subject " Procedure To Machine Transmission Shaft Assemblies".

6. After the machining is complete, assemble the second speed clutch (#4) with the existing parts. No new parts are added to this clutch.

7. Turn the shaft assembly over and assemble the reverse clutch (#3) using the new parts shown in Illustration 1 and 2. Apply a small amount of 9S3263 Thread Lock Compound to the 5C7423 Screws at installation. They should be tightened to a torque of 12 +/- 3 NM (107 +/- 27 inch lb.). Be sure the heads of the screws are below the surface of the 161-6713 Washer after tightening.

8. Assemble the two forward clutches (#1 & #2) using the new parts as shown in Illustration 3 and 2. Be sure to apply a small amount of 9S3263 Thread Lock Compound to the 5C7423 Screws at installation. Tightened the screws to a torque of 12 +/- 3 NM (107 +/- 27 inch lb.). Be sure the heads of the screws are below the surface of the 161-6713 Washer after tightening.

9. Assemble the transmission.

10. If a test bench is available, test the transmission for proper operation. If a test bench is not available, the transmission can be tested after installation into the machine.

11. Install the transmission into the machine.

12. Test the machine for proper operation.

PROCEDURE TO MACHINE TRANSMISSION SHAFT ASSEMBLIES

Both the FORWARD shaft assembly (6Y1885) and the REVERSE/SECOND shaft assembly (6Y2424) require salvaging by machining the grooves wider to accept the different lock rings. The machining of the grooves will have to be done by grinding. The shafts are hardened to Rockwell C 57 to a depth of 0.6 to 1.0 MM. At 1.4 MM depth the hardness should be Rockwell C 30.

NOTE: If the choice is made to purchase new shaft assemblies instead of salvaging the old ones, the cost of the new shaft assembly will not be reimbursed. ONLY the cost to machine the shaft set forth in this Service Letter will be reimbursed.
1. FORWARD SHAFT ASSEMBLY---6Y1885. This shaft contains both the forward clutches, #1 & #2. Both grooves on this shaft need to be machined wider to a dimension of 7.82 +/- 0.13 MM (0.308 +/- 0.005 inches), see Illustration 4. As shown, material must be removed from the spline side of the groove ONLY. This is very important!! If material is removed from the other side of the groove, the clutch will not have the proper running clearance. Clean up of 100% is required on the groove I.D. of 65.65 +/- 0.04 MM (2.585 +/- 0.002 inches). A 65.57 MM (2.581 inch) groove diameter will be acceptable.

2. REVERSE/SECOND SHAFT ASSEMBLY---6Y2424. This shaft contains the reverse clutch (#3) and the second speed clutch (#4). Only the groove for the reverse clutch (#3) needs to be machined, see Illustration 5. Widen the reverse clutch groove to 7.82 +/- 0.13 MM (0.308 +/- 0.005 inches). ONLY remove material from the spline side of the groove. Clean up of 100% is required on the groove I.D. of 65.65 +/- 0.04 MM (2.585 +/- 0.002 inches). A 65.57 MM (2.581 inch) groove diameter will be acceptable.