PRODUCT SUPPORT PROGRAM FOR REPLACING THE MOTOR LIP SEAL ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS Caterpillar

PRODUCT SUPPORT PROGRAM FOR REPLACING THE MOTOR LIP SEAL ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS

Usage:

REBE8921-03

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31Oct2012

(Revised 20May2013)

U-578

A-457

D-495

O-532

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*Before/After*	PRODUCT SUPPORT PROGRAM FOR REPLACING THE MOTOR LIP SEAL ON CERTAIN 795F AC OFF-HIGHWAY TRUCKS
1603 5927 4008 3260		PS43743

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NOTE:

This Program must be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS43743" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and "T" as the SIMS Description code. If administered after failure, use "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 31Oct2012 (Revised 09May2013) Service Letter. Changes were made to replace the non-servicable parts listed in the Parts Needed. There were 2 parts in the parts list that were not serviceable (345-3922 & 352-6500). These parts were updated with their serviceable components.

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TERMINATION DATE

31Oct2014

PROBLEM

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Under certain conditions of the 795F Off-Highway Trucks the lip seal on the motor can wear prematurely and allow final drive oil to leak past the seal. Once the oil leaks past the seal it will drain into the bearing grease reservoir box. If a large enough amount of oil leaks past the seal it will eventually fill and overflow the collection box. The final drive oil will then be blown by the cooling air stream and contaminate the motor windings. This will lead to debris collecting on the motor coils causing it run hotter than normal and negatively affecting motor performance. Final drive oil will also collect at the bottom of the motor or underneath the motor in the rear axle housing. A collection of oil either in or underneath the motor is the best evidence that the lip seal should be replaced. The picture shows a motor that has experienced a lip seal failure.

If the wheel station is off of the truck for any reason the lip seal should be updated as it is a simple procedure.

AFFECTED PRODUCT

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Model	Identification Number
*****Group 1*****
795F AC	ERM00153-00164, 166-169

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*****Group 2*****
795F AC	ERM00202-00222, 224-238

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*****Group 3*****
795F AC	ERM00165, 170, 193, 223

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*****Group 4*****
795F AC	ERM00171-00192, 194-201

PARTS NEEDED

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Qty	Part Number	Description
*****Group 1*****
14	3E6910	BOLT-HEX SOCKET
1	3J5390	PLUG-NPTF
4	3J7354	SEAL-O-RING
2	3K0360	SEAL-O-RING
2	5P2545	SEAL-O-RING
6	6V8397	SEAL-O-RING-ORFS
2	6V9168	NUT-BULKHEAD
4	6V9872	ADAPTER-STR
2	7X2537	BOLT-HEX HEAD
2	8B2664	BUSHING-REDUCING
4	8C6870	ADAPTER-STR
2	8C8835	ADAPTER-STR
2	8M2773	CLIP-LOOP
2	8T0664	BOLT-HEX HEAD
4	8T4121	WASHER-HARD
4	8T4137	BOLT-HEX HEAD
2	8T4224	WASHER-HARD
2	9C4937	BREATHER AS
2	9C6809	BLOCK
4	1242114	COUPLING AS-PERM
2	1242130	COUPLING-PERM
2	1242323	COUPLING-PERM
2	1265211	SPACER
2	1454496	HOSE AS
106	1470169	BOLT-HEX HEAD (After Failure Only)
2	1499129	CLIP-LOOP
14	1912845	WASHER-SEALING
2	2287089	SEAL-O-RING-ORFS
2	2353350	BRACKET
2	3002842	HOSE AS
2	3144127	RING-TORIC (After Failure Only)
2	3453921	ADAPTER-STR
2	3842603	SEAL-WEAR SLEEVE
2	3882249	SEAL-LIP TYPE
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 31% 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.
*****Group 2*****
14	3E6910	BOLT-HEX SOCKET
2	3K0360	SEAL-O-RING
2	6V8397	SEAL-O-RING-ORFS
2	6V9168	NUT-BULKHEAD
2	8B2664	BUSHING-REDUCING
2	8C6870	ADAPTER-STR
2	8C8835	ADAPTER-STR
4	8T4121	WASHER-HARD
4	8T4137	BOLT-HEX HEAD
2	9C4937	BREATHER AS
2	9C6809	BLOCK
14	1017402	BOLT-HEX SOCKET
2	1454496	HOSE AS
106	1470169	BOLT-HEX HEAD (After Failure Only)
2	2287089	SEAL-O-RING-ORFS
2	2353350	BRACKET
2	3144127	RING-TORIC (After Failure Only)
2	3453921	ADAPTER-STR
2	3842603	SEAL-WEAR SLEEVE
2	3882249	SEAL-LIP TYPE
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 31% 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.
*****Group 3*****
1	3J5390	PLUG-NPTF
4	3J7354	SEAL-O-RING
2	3K0360	SEAL-O-RING
6	6V8397	SEAL-O-RING-ORFS
2	6V9168	NUT-BULKHEAD
4	6V9872	ADAPTER-STR
2	7X2537	BOLT-HEX HEAD
2	8B2664	BUSHING-REDUCING
4	8C6870	ADAPTER-STR
2	8C8835	ADAPTER-STR
2	8M2773	CLIP-LOOP
2	8T0664	BOLT-HEX HEAD
4	8T4121	WASHER-HARD
4	8T4137	BOLT-HEX HEAD
2	8T4224	WASHER-HARD
2	9C4937	BREATHER AS
2	9C6809	BLOCK
4	1242114	COUPLING AS-PERM
2	1242130	COUPLING-PERM
2	1242323	COUPLING-PERM
2	1265211	SPACER
106	1470169	BOLT-HEX HEAD (After Failure Only)
2	1499129	CLIP-LOOP
2	2287089	SEAL-O-RING-ORFS
2	2353350	BRACKET
2	3144127	RING-TORIC (After Failure Only)
2	3453921	ADAPTER-STR
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 31% 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.
*****Group 4*****
1	3J5390	PLUG-NPTF
4	3J7354	SEAL-O-RING
2	3K0360	SEAL-O-RING
6	6V8397	SEAL-O-RING-ORFS
2	6V9168	NUT-BULKHEAD
4	6V9872	ADAPTER-STR
2	7X2537	BOLT-HEX HEAD
2	8B2664	BUSHING-REDUCING
4	8C6870	ADAPTER-STR
2	8C8835	ADAPTER-STR
2	8M2773	CLIP-LOOP
2	8T0664	BOLT-HEX HEAD
4	8T4121	WASHER-HARD
4	8T4137	BOLT-HEX HEAD
2	8T4224	WASHER-HARD
2	9C4937	BREATHER AS
2	9C6809	BLOCK
14	1017402	BOLT-HEX SOCKET
4	1242114	COUPLING AS-PERM
2	1242130	COUPLING-PERM
2	1242323	COUPLING-PERM
2	1265211	SPACER
2	1454496	HOSE AS
106	1470169	BOLT-HEX HEAD (After Failure Only)
2	1499129	CLIP-LOOP
2	2287089	SEAL-O-RING-ORFS
2	2353350	BRACKET
2	3002842	HOSE AS
2	3144127	RING-TORIC (After Failure Only)
2	3453921	ADAPTER-STR
2	3842603	SEAL-WEAR SLEEVE
2	3882249	SEAL-LIP TYPE
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 31% 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.

NOTE: Bolt 147-0169 was originally set to be replaced after failure only, but needs to be replaced after bolt removal.

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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%
*****Group 1*****
0-14000 hrs, 0-36 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

NOTE: This is a 11.0-hour job for Group 1 If there has been a previous repair, part age/hours will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
For a before failure the 11-hour allowance covers rework of the breathers and the lip seals once the wheel station is removed. For an after failure repair the allowance is increased to a total of 73 hours to cover wheel station R&I.

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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%
*****Group 2*****
0-14000 hrs, 0-36 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

NOTE: This is a 6.0-hour job for Group 2 If there has been a previous repair, part age/hours will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
For a before failure the 2-hour allowance covers rework of the lip seals once the wheel station is removed. An additional 4-hour allowance covers the movement of the motor breathers from the axle housing to the frame. For an after failure repair the allowance is increased to a total of 68 hours to cover wheel station R&I and includes the movement of the motor breathers from the axle housing to the frame.

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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%
*****Group 3*****
0-14000 hrs, 0-36 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

NOTE: This is a 71.0-hour job for Group 3
For a before or after failure repair the 71-hour allowance covers wheel station R&I and the breather rework.

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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%
*****Group 4*****
0-14000 hrs, 0-36 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

NOTE: This is a 11.0-hour job for Group 4
For a before failure repair the 11-hour allowance covers rework of the breathers and the lip seals once the wheel station is removed. For an after failure repair the allowance is increased to a total of 73 hours to cover wheel station R&I.

PARTS DISPOSITION

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

Rework Procedure

Group Number 1

Below is the evidence that a lip seal has failed and allowed final drive oil to leak into the motor and rear axle housing.

Image1.1.1

For after failure service claims only remove Final Drive Brake and Wheel Group. Refer to KENR8715-06 for instructions. If this is a before failure claim, the Final Drive, Brake and Wheel Gp. should already be removed for an unrelated repair and any labor or expenses related to the Final Drive, Brake, and Wheel Gp. removal will not be part of the Service Claim Allowance.

For machines that are in Group 1, the lip seals/wear sleeves and breathers will need to be installed. The motors in this group should have an O-ring behind the bearing cover.

Use the following instructions for the new breather installation.

Remove the existing breather and connecting lines and install a 3J-5390 Pipe Plug in the port located in the center of the rear axle housing.

Image1.2.1

Drill two holes in the banjo housing using dimensions on the pictures below.

Image1.3.1

Image1.3.2

Image1.3.3

Weld on the 9C-6809 Blocks (2) to the frame for mounting of breathers and brackets. Use a 6 mm fillet weld on the top and bottom of the blocks. Refer to details below for dimensions.

Image1.4.1

Image1.4.2

Image1.4.3

Install the 235-3350 Bracket, 8T-4121 Washers, and 8T-4137 Bolts (3).
Install the 9C-4937 Breather, 345-3921 Adapter, 3K-0360 Seal, 8C-8835 Adapter, and 228-7089 Seal(4).
Install the 6V-8397 Seal, 145-4496 Hose, 6V-9872 Adapter, 6V-8397 Seal, and 3J-7354 Seal (5).
Install the 8M-2773 Clip, 126-5211 Spacer, 149-9129 Clip, 7X-2537 Bolt, 8T-4224 Washer, 8B-2664 Bushing, 8C-6870 Adapter, and 300-2842 Hose (6).

Repeat this process for the opposite side.

There are two populations of motors that need to have the lip seal replaced. The first population consists of motors with serial numbers B5T00358 and earlier. These motors should be in Groups 1. These motors use an O-ring behind the bearing cover.

Motors after B5T00358 do not use an O-ring and should be in Group 2 and 4. Each of these populations of motors use different fasteners to secure the bearing cover to the bearing retainer. Both motors use the same new lip seal and wear sleeve.

NOTE: There may be a few instances where a motor may have been installed that does not match the group described above. Please note the motor serial number and follow the instructions relevant for that level of motor. Contact your industry service rep with any questions or concerns.

Tooling is required to remove the old lip seal and install the new lip seal into the bearing cover and to install the wear sleeve onto the shaft.

The part number for the lip seal driver to remove and install the lip seal is 369-3831.

Image1.7.1

Image1.7.2

The wear sleeve can be installed with a basic tool developed for installation of prototype hardware or with the released dealer service tool.

The print for the basic tool is shown.

The dealer service tool part numbers for the wear sleeve driver is 415-1721.

The main difference in the two tools is that a dead blow hammer is used to drive the sleeve on with the basic tool while the dealer service tool uses a screw to drive on the sleeve.

Image1.8.1

Note: Other tools and required sealants are listed below:
...Handle + Bolt for Lip-Seal Driver
...(4) M12 Guide-Studs
...(4) M12 Forcing-Bolts
...Loctite 5188 Anaerobic Sealant for Bearing-Cover
...Hi-Strength (red) Threadlock (Loctite 271 or equivalent)
...Brushes or Roller to apply Sealant and Grease (e.g. Acid Brushes)
...Tape to cover Splines (e.g. Masking-Tape or Painters-Tape works best)
...M12x1.75 Tap to clean threadlock from threaded holes in Endbell
...Citrus-based Degreaser to clean Motor windings if required (no solvents)

Inspect & Clean Motor This section applies only to Motors in service that suffered a Lip-Seal failure and allowed Final Drive oil into the Motor.

Remove Grease Reservoir - Empty & reinstall Grease Reservoir.

Inspect the Motor Drive-End Windings & inside of Motor Frame for oil / contamination. Inspect the opposite Motor Non-Drive-End for oil / contamination also.

Clean oil / contamination from both Motors using a citrus-based degreaser? do not use solvents.

Check Motor Insulation Resistance of both Motors after cleaning ? minimum acceptable resistance @ 2500V test voltage is 5 MOhm. Contact Product Support if Insulation Resistance is less than 5 MOhm ? Motor may have to be replaced.

Remove the 368-8034 Coupler. The 6V-8133 Bolt will not be reused.

Clean-up any Final Drive Oil that may have run into Motor or Rear Axle during Wheel-Station removal.
Remove four M12 bolts holding the Bearing-Cover in place and install four M12 Guide-Studs.
Remove the remaining three M12 bolts and install two M12 Forcing-Bolts to remove the Bearing-Cover.
Remove the four M12 Guide-Studs from Motor.

Remove old thread-lock from the seven threaded holes in End-Bell for Bearing-Cover using M12 Tap.
Remove any loose red paint from Bearing-Cover and Bearing Retainer.
Remove any remains of hardened anaerobic sealant from mating surface of Bearing Retainer still installed on Motor; clean / degrease and dry mating surface.

Clean old lip seal running surface of any debris.

Image1.11.1

Image1.11.2

Image1.11.3

Image1.11.4

Load wear sleeve into install tooling. Inner taper on the wear sleeve should be first to pilot onto shaft. Place install tooling with the inserted wear sleeve over the shaft and seat using just your hands. If using the simple tooling (shown) use dead blow hammer to drive sleeve onto shaft and seat against bearing nut. If using the dealer service tool use nut to drive sleeve onto the shaft.

Image1.12.1

Image1.12.2

Bolt the Handle to the large dia side of the Lip-Seal Driver.
Using the small diameter side of the Seal-Driver, press out the Lip-Seal from the inboard side of the Bearing-Cover.
Remove O-Ring (if applicable) from inboard side of Bearing-Cover.
Remove any hardened anaerobic sealant from mating surface on inboard side of Bearing-Cover; clean / degrease and dry mating surface.

Image1.13.1

Image1.13.2

Cover Splines with a thin layer of Masking or Painters Tape to protect Seal-Lip from damage during installation.
Reinstall the four M12 Guide-Studs into Motor (four Guide-Studs recommended to minimize deformation of Lip-Seal when installing).
Bolt the Handle to the small dia side of the Lip-Seal Driver.
Remove the inner packaging ring from the seal

Image1.14.1

Image1.14.2

Image1.14.3

Image1.14.4

Install the new Lip-Seal into the bore in the outboard side of the Bearing-Cover:
+ New Lip faces outboard. DO NOT touch or deform the lip material!
+ Use the larger dia face of the Driver to press against the Lip-seal Housing OD.
+ Drive the Lip-Seal housing into the bore as straight as possible - for best results a small arbor press should be used if available. Inspect to insure the Lip-Seal housing is seated against the backface of the Bearing-Cover all the way around, and the Lip-Seal is not cocked in the bore.

Install new 5P-2545 O-Ring in inboard side Bearing-Cover ? use CAT Hi-Speed Ball-Bearing Grease or O-Ring Retaining Compound to hold O-Ring in groove.
Degrease and dry mating surface of Bearing-Cover, between O-Ring groove (if applicable) and OD of Cover.
Apply a bead of Loctite Flexible Anaerobic Gasket Sealant and spread out to fully cover the above mating surface ? insure the sealant covers the critical area between bolt clearance holes and OD of Bearing-Cover. DO NOT allow any anaerobic sealant to get on O-Ring or Lip-Seal.

Image1.16.1

Image1.16.2

Place Bearing-Cover on the four Guide-Bolts installed into the Motor.
Carefully support and guide straight the Bearing-Cover over Splines and Wear-Sleeve on Shaft until Bearing-Cover contacts Bearing-Retainer ? minimize contact between Lip and Splines and deformation of Lip-Seal. Insure the O-Ring in back of the Bearing-Cover does not come out of the groove during installation. Once the Lip has been compressed by mounting on the Wear-Sleeve, the Lip Seal cannot be removed and then reused.
Install 191-2845 O-Ring Washers on seven (3E 6910) M12 Bolts and apply hi-strength threadlock (red) to threads.
Install three Bolts snug.
Remove the four Guide-Studs and install remaining four M12 Bolts.
Tighten all seven M12 Bolts in a cross pattern to a torque of 83 Nm.

Empty & reinstall Grease Reservoir if not previously done.

Image1.17.1

Image1.17.2

If this is a before failure service claim, this completes the repair. If this is an after failure service claim, install the final drive, brake, and wheel group.

Refer to KENR8715. All of the 147-0169 Bolts need to be replaced when installing this assembly.

Group Number 2

Machines in Group 2 need to have the lip seals and wear sleeves updated and need to move the motor breathers from the axle housing to the frame. Machines in this group should not use an O-Ring behind the bearing cover.

Image2.1.1

The rework procedure for motors in this group is identical to the procedure in Group 1 except for a few minor differences. There is no O-ring on the back of the bearing cover and the sealant can be applied without worrying about the O-ring. There are no washers used on the bolts to attach the bearing cover to the bearing retainer. The M12 bolts used to attached the cover to the retainer are 101-7402.

Image2.2.1

Machines in Group 2 also need to move the breathers from the axle housing to the frame. Unlike machines in Group 1, machines in Group 2 already have 2 breathers installed on the axle housing. Machines in Group 2 need to install two 145-4496 hoses to the housing and attach the 9C-4937 breathers to the 9C-6809 blocks using the parts provided for Group 2. Refer to the instructions in Group 1 for dimensions, pictures, and parts identification.

Group Number 3

Machines in Group 3 only need to have breathers installed. Please follow instructions for breather installation found in Group 1.

Group Number 4

Machines in Group 4 need to have both breathers and lip seals/wear sleeves installed. The breathers should be installed following instructions from Group 1 and the lip seals should be installed following instructions in Group 2.