PRODUCT IMPROVEMENT PROGRAM FOR REPLACING THE 375-5423 BEARING ASSEMBLY ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT IMPROVEMENT PROGRAM FOR REPLACING THE 375-5423 BEARING ASSEMBLY ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS

Usage:

REBE7874-01

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04May2012

(Revised 10Sep2012)

U-247

A-198

D-210

O-225

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*Priority*	PRODUCT IMPROVEMENT PROGRAM FOR REPLACING THE 375-5423 BEARING ASSEMBLY ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS
4017 1636		PI32029

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NOTE:

This Program must be administered as soon as possible. When reporting the repair, use "PI32029" 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 "PI32029" 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 04May2012 Service Letter. Changes have been made to the Affected Product.

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COMPLETION DATE	TERMINATION DATE
30Nov2012	31May2013

PROBLEM

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The 375-5423 bearing assembly needs to be replaced on certain 795F AC Off-Highway Trucks. The existing bearing assembly can fail, potentially resulting in failures of the blower fan and electric drivetrain system. To reduce the chance of resultant damage, the bearing assembly should be replaced before it reaches 2000 SMU of time in service.

AFFECTED PRODUCT

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Model	Identification Number
795F AC	ERM00153-00222

PARTS NEEDED

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Qty	Part Number	Description
4	8T6868	BOLT-HEX HEAD
6	8T7338	BOLT-HEX HEAD
4	1124159	MOUNT AS.
60	1175821	WIRE-LOCK(BULK)
8	1984780	WASHER-HARD
2	2907507	BOLT-12 POINT HD
1	3906875	BEARING-LOAD A
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 44% 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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Refer to the attached Rework Procedure and replace the existing bearing assembly with a new 390-6875 Bearing Assembly.

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OWNER NOTIFICATION

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U.S. and Canadian owners will receive the attached Owner Notification.

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 12.0-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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COPY OF OWNER NOTIFICATION FOR U.S. AND CANADIAN OWNERS

XYZ Corporation
3240 Arrow Drive
Anywhere, YZ 99999

PRIORITY - PRODUCT IMPROVEMENT PROGRAM FOR REPLACING THE 375-5423 BEARING ASSEMBLY ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS

MODELS INVOLVED - 795F AC Off-Highway Trucks

Dear Caterpillar Product Owner:

The 375-5423 Bearing Assembly needs to be replaced on the products listed below. The existing bearing assembly can fail, potentially resulting in failures of the blower fan and electric drivetrain system. To reduce the chance of resultant damage, the bearing assembly should be replaced before it reaches 2000 SMU of time in service. You will not be charged for the service performed.

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

Please refer the dealer to their Service Letter dated 04May2012 when scheduling this service.

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

Caterpillar Inc.

Identification #(s)

Attached to 04May2012 Service Letter

Rework Procedure

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Disconnect the electrical harnesses from the hydraulic motor. Remove the hose mounting hardware from blower frame (1).

While supporting the hydraulic motor, remove the motor mounting bolts (2). Swing the motor to the side to clear the frame and secure it.

Image1.1.1

Remove Blower Fan (3). Refer to Disassembly and Assembly KENR8727 "Blower Fan - Remove."

Image1.2.1

Remove four bolts and washers (4). The bolts and mounts will not be reused. Retain the washers. Separate the housing from the frame.

Image1.3.1

From the top of blower assembly (5), document how the safety wire is routed. Cut the safety wire and remove the four bolts that join the fan to the bearing assembly. NOTE: Retain these bolts; they will be reinstalled.

Image1.4.1

Support the bearing assembly and remove the four bolts that join the adapter to blower housing (6). Remove the bearing assembly.

Image1.5.1

The new assembly uses six bolts (7). Using the measurements in the illustration below, drill two additional 18 mm holes in housing (8).

Image1.6.1

Image1.6.2

Apply a thin layer of 4C-5599 or equivalent anti-seize compound to shaft (9) of the new 390-6875 Bearing Assembly and the bushing of the fan. Apply 3S-6252 (EAME 185-3986) or equivalent RTV black silicone to surface (10) of the bearing assembly that will mate to the fan housing.

Carefully insert the bearing assembly into the fan assembly. Using six new 8T-7338 Bolts and 198-4780 Washers, apply Loctite 242 Blue Threadlocker to the threads and mount adapter to fan housing. See PEGJ0075 for Cat/Loctite cross reference information. Tighten the bolts to a torque of 150 N-m (110 ft-lb). NOTE: Do not reinstall the split washers (if equipped) when installing the new bolts.

Image1.8.1

Apply thin layer of 4C-5599 or equivalent anti-seize compound to the four bolts that retain the fan assembly to the bearing assembly. Tighten four bolts alternately in three to five steps until a torque of 40 N-m (29 lb-ft) is reached. Loop 117-5821 locking wire through the holes of the bolt heads as previously documented before removal. Twist ends of wire together a minimum of six twists and cut excess wire.

Using the existing 8T-4223 and 246-7080 Washers, install new 112-4159 Mounts and 8T-6868 Bolts to attach the blower group to the mounting frame. Tighten the bolts to a torque of 100 N-m (75 lb-ft).

Reassemble the blower mounting frame to truck frame. Refer to Disassembly and Assembly KENR8727 "Blower Fan - Install." Tighten the bolts to a torque of 240 N-m (175 lb-ft).

Apply Cat Ultra 5Moly grease to splined shaft of hydraulic fan motor. Using new 290-7507 Bolts and one new 198-4780 Washer for each bolt, install motor to bearing assembly. Tighten the bolts to a torque of 240 N-m (175 lb-ft.). NOTE: Upon disassembly, some fan motors may have two 198-4780 Washers for each mounting bolt. Use only one 198-4780 Washer for each 290-7507 Bolt when performing this Service Letter.

Attach the remaining hardware. Adjust the blower fan speed. Refer to Special Instruction REHS4427 - Commissioning Procedure For the 795F AC Off-Highway Truck - "Set Drivetrain Cooling Fan Speed" in Service Information.