PRODUCT IMPROVEMENT PROGRAM FOR ADJUSTING THE TRANSMISSION MAIN RELIEF VALVE ON CERTAIN 797F AND 797F XQ OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT IMPROVEMENT PROGRAM FOR ADJUSTING THE TRANSMISSION MAIN RELIEF VALVE ON CERTAIN 797F AND 797F XQ OFF-HIGHWAY TRUCKS

Usage:

TEBE5652-02

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25Jan2017

(Revised 12Jun2017)

U-49

A-31

D-38

O-41

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Priority	PRODUCT IMPROVEMENT PROGRAM FOR ADJUSTING THE TRANSMISSION MAIN RELIEF VALVE ON CERTAIN 797F AND 797F XQ OFF-HIGHWAY TRUCKS
3030 3155 4095 3182 3133 3167		PI32726

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NOTE:

Caterpillar’s obligations under this Service Letter are subject to, and shall not apply in contravention of, the laws, rules, regulations, directives, ordinances, orders, or statutes of the United States, or of any other applicable jurisdiction, without recourse or liability with respect to Caterpillar.

NOTE:

This Program must be administered as soon as possible. When reporting the repair, use "PI32726" as the Part Number and "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description code. Exception: If the repair is done after failure, use "PI32726" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.

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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.

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NOTE:	This Revised Service Letter replaces the 25Jan2017 (Revised 09Feb2017) Service Letter. Changes have been made to the Affected Product.

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COMPLETION DATE	TERMINATION DATE
31Jul2017	31Jan2018

PROBLEM

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The 438-2216 Relief Valve Group needs to be reworked on certain 797F and 797F XQ Off-Highway Trucks, equipped with 446-9392 and 20R-3632 Transmission Arrangements (Transmission Serial Number prefix JH5 and JH5R).

The existing 438-2216 Relief Valve pressure setting (460 +/- 20 psi-High Idle, 410 psi +/-25 psi-Low Idle) can cause excessive clutch 7 friction disc wear due to excessive net unit pressure. The excessive clutch 7 friction disc wear can result in failure of the 444-7646 Clutch 7 Wave Springs. These issues may result in prematurely failing transmission clutch 7.

AFFECTED PRODUCT

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Model	Identification Number
797F	LAJ00142, 150, 158-162, 164-165, 169-170, 175-180, 182, 184-187, 192-193, 195-197, 203, 205-206, 210-211, 213-214, 216-218, 220-221, 224-227, 229, 231-233, 237-248, 250-253, 263-270, 272-274, 276, 281-290, 293-296, 298-299, 301-308, 315, 320-324, 329, 334-336, 338, 340, 342, 345-346, 348-349, 352-364, 366-370, 374, 376, 378-379, 382-389, 391-396, 398, 400-402, 404-407, 409-412, 415, 417-418, 420, 422-425, 427-428, 430-434, 436-441, 443-445, 447, 449-451, 453, 455-458, 460, 462, 469, 473-475, 477-482, 484-486, 488, 491, 493-494, 499-604
797F XQ	WSP00100-00129

PARTS NEEDED

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Qty	Part Number	Description
1	2859208	GASKET
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 40% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.

ACTION REQUIRED

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The 438-2216 Relief Valve Group needs to be reworked to lower the Transmission Main Relief pressure setting. Refer to the attached Rework Procedure to adjust the pressure and rework the Relief Valve Part Number to 151-0187.

Please note the Relief Valve pressure setting is adjustable and does not require Relief Valve replacement.

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OWNER NOTIFICATION

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Owners in the following countries will receive the attached Owner Notification:
US
Canada

SERVICE CLAIM ALLOWANCES

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Caterpillar		Dealer Suggested		Customer Suggested
Parts %	Labor Hrs%	Parts %	Labor Hrs%	Parts %	Labor Hrs%
100%	100%	0%	0%	0%	0%

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NOTE: This is a 2.0-hour job

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PARTS DISPOSITION

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

MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.

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EXAMPLE COPY OF OWNER NOTIFICATION

XYZ Corporation
3240 Arrow Drive
Anywhere, YZ 99999

PRIORITY - PRODUCT IMPROVEMENT PROGRAM FOR ADJUSTING THE TRANSMISSION MAIN RELIEF VALVE ON CERTAIN 797F AND 797F XQ OFF-HIGHWAY TRUCKS

MODELS INVOLVED - 797F and 797F XQ Off-Highway Trucks

Dear Cat Product Owner:

The Transmission Relief Valve needs to be adjusted on the products listed below. The existing Relief Valve Pressure setting can cause excessive clutch 7 friction disc wear and eventual clutch failure. You will not be charged for the service performed.

Contact your local Cat dealer immediately to schedule this service. The dealer will advise you of the time required to complete this service.

If you are no longer the owner of this product(s), please contact your local Cat dealer so that our records can be updated. Please refer the dealer to their Service Letter dated 25Jan2017 when scheduling this service.

We regret the inconvenience this may cause you, and urge you to have this service performed as soon as possible to prevent unscheduled downtime.

Caterpillar Inc.

Identification #(s)

Attached to 25Jan2017 Service Letter

Rework Procedure

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797F and 797F XQ JH5(R) Transmission Relief Valve Pressure Adjustment Procedure

Please refer to Test and Adjust Manual KENR8371- Transmission Test for additional information as required.

Parts/Tools Required
198-4240 Digital Pressure Group (or similar pressure reading tool. 0-500 psi scale).

Step 1. Remove the transmission top cover and bolts allowing access to the transmission input planetary/controls group. Verify that the transmission top cover and edges have been thoroughly cleaned to prevent debris from entering the transmission during removal.

Image1.1.1

1. Remove bolts (10) from cover (11).

Image1.2.1

Step 2. Attach a suitable lifting device to cover (11). Remove cover (11) and the gasket. The weight of cover (11) is approximately 45 kg (100 lb)

The transmission hydraulic control relief valve is located under the cover on the transmission.
Transmission hydraulic control relief valve
(12) Main relief valve
(13) Cover
(14) Adjustment screw

Image1.3.1

The pressure reading for the main relief pressure at pressure tap (8) should be set to 385 +/- 20 psi at High idle engine speed (Neutral gear, transmission oil at operating temperature) and 335 +/- 20 psi at Low idle engine speed). Adjust the spring on the transmission hydraulic control relief valve to set to the desired pressure.

Image1.4.1

Use the following procedure.
1. Remove cover (13) on the main relief valve.
2. Turn adjustment screw (14) in the proper direction.

Turning the adjustment screw clockwise increases pump pressure. Turning the adjustment screw counterclockwise decreases pump pressure. Turning the adjustment screw 1 full revolution counterclockwise is roughly the amount needed to reach the required pressure reduction (high idle setting).
3. Change the Relief Valve part number (however marked) from 438-2216 to 151-0187 to indicate the pressure setting adjustment.
4. Install cover (14).
5. Check the main relief pressure again to confirm the pressure.

Note: After the Transmission Main Relief Valve Pressure has been adjusted, the transmission Pressure and Fill Calibrations need to be completed.

Reference: For information on calibrating the engagement pressure for the transmission clutch, refer to Testing and Adjusting, KENR8394, "Engagement Pressure for the Transmission Clutch - Calibrate".

Reference: For information on calibrating the transmission clutch fill time, refer to Testing and Adjusting, KENR8394, "Fill Time for the Transmission Clutch - Calibrate".