PRODUCT SUPPORT PROGRAM FOR REWORKING RIGHT SIDE REAR AXLE HOUSING HARNESS ASSEMBLY CONNECTIONS AND REAR WHEEL TRACTION MOTOR AIR COOLING FLEX HOSE ON CERTAIN 794 AC OFF-HIGHWAY HIGHWAY TRUCKS Caterpillar

PRODUCT SUPPORT PROGRAM FOR REWORKING RIGHT SIDE REAR AXLE HOUSING HARNESS ASSEMBLY CONNECTIONS AND REAR WHEEL TRACTION MOTOR AIR COOLING FLEX HOSE ON CERTAIN 794 AC OFF-HIGHWAY HIGHWAY TRUCKS [UEBE0249]

ELECTRICAL AND STARTING SYSTEM

WIRING GP

PRODUCT SUPPORT PROGRAM FOR REWORKING RIGHT SIDE REAR AXLE HOUSING HARNESS ASSEMBLY CONNECTIONS AND REAR WHEEL TRACTION MOTOR AIR COOLING FLEX HOSE ON CERTAIN 794 AC OFF-HIGHWAY HIGHWAY TRUCKS

UEBE0249-02

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03Jun2020

(Revised 18Sep2020)

U-363

A-306

D-348

O-343

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Before/After	PRODUCT SUPPORT PROGRAM FOR REWORKING RIGHT SIDE REAR AXLE HOUSING HARNESS ASSEMBLY CONNECTIONS AND REAR WHEEL TRACTION MOTOR AIR COOLING FLEX HOSE ON CERTAIN 794 AC OFF-HIGHWAY HIGHWAY TRUCKS
7755 1408 4017 7051 3260		PS46753

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NOTE:

AVSpare’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 AVSpare.

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 "PS46753" 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 AVSpare product analyst.

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NOTE:	This Revised Service Letter replaces the 03Jun2020 (Revised 04Jun2020) Service Letter. Changes have been made to Affected Product, Parts Needed, Service Claim Allowances and Rework Procedure.

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TERMINATION DATE

30Jun2022

PROBLEM

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The existing right side rear axle housing harness assembly interface connections can chafe on the traction motor cooling flex hose on certain 794 AC Off-Highway Trucks. The chaffing can result in a tear in the flex hose.

AFFECTED PRODUCT

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Model	Identification Number
794 AC	HRT00100-00106 MN500052-00056 MT500100-00154

PARTS NEEDED

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Qty	Part Number	Description
4	1B2706	BOLT-CARRIAGE
8	3E7447	CLAMP-HOSE
1	3G4005	LINK
1	4E7829	BLOCK
4	5C8312	NUT-HEX
6	5P1076	WASHER-HARD
4	5P7464	CLIP-HALF SLOT
4	5P7465	CLIP-HALF TANG
2	5P7466	CLIP-2 PIECE
2	5P7467	CLIP
2	5P8112	GROMMET
4	6V1249	GROMMET
1	6V8639	ADAPTER-STR
4	6V8801	NUT-HEX
1	6V9007	ADPTR-ELB 90 DEG
1	6V9182	ADAPTER-ELBOW
1	6V9852	ADAPTER-ELBOW
10	7K1181	STRAP-CABLE
2	7Y2522	PLATE
2	7Y7259	BOSS
8	8C9660	WASHER
36	8T4121	WASHER-HARD
1	8T4136	BOLT-HEX HEAD
10	8T4137	BOLT-HEX HEAD
4	8T4139	BOLT-HEX HEAD
4	8T4185	BOLT-HEX HEAD
4	8T4192	BOLT-HEX HEAD
8	8T4195	BOLT-HEX HEAD
3	8T4196	BOLT-HEX HEAD
2	8T4223	WASHER-HARD
1	8T8899	ADAPTER-ELBOW
1	8X4903	BLOCK
1	9C4935	PLATE
1	9R2613	BOSS
1	9R2672	BOSS
2	9R3761	BOSS
4	0919035	SPACER-HARD
1	1028802	KIT-RCPT CONN
1	1028803	KIT-RCPT CONN
5	1261767	PIN-CONNECTOR
5	1261768	SOCKET-CONNECTOR
1	1273387	BOSS
1	1387538	ADAPTER-STR
1	1552260	KIT-PLUG CONN
1	1552270	KIT-PLUG CONN
4	1622165	BOLT-HEX
1	1639662	BOSS
1	1935576	BRACKET AS.
4	1947882	SPACER
7	2042281	STRAP-CABLE
7	2048000	MOUNT-TIE WRAP
1	2110052	NUT-HEX
1	2287090	SEAL-O-RING-ORFS
2	2287091	SEAL-O-RING-ORFS
3	2287092	SEAL-O-RING-ORFS
1	2385080	SEAL-O-RING-STOR
1	2385082	SEAL-O-RING-STOR
2	2385084	SEAL-O-RING-STOR
1	2909001	BRACKET AS
1	2909002	BRACKET
5	3445675	NUT-HEX
1	3501571	BRACKET AS
9	3668856	HARNESS-BULK (DECIMETERS)
1	3979469	BRACKET AS
1	3981083	BRACKET
4	5635509	BRACKET
4	5765522	STRIP
2	5832100	RING
1	5834389	PLATE AS
1	5849665	HOSE AS
2	5867996	BRACKET
1	5901993	HOSE AS
1	PLATE_001	DEALER FABRIAVSED
1	PLATE_002	DEALER FABRIAVSED
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 28% 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.

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SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	AVSpare		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts %	Labor Hrs%	Parts %	Labor Hrs%	Parts %	Labor Hrs%
0-48000 hrs, 0-72 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%

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NOTE: This is a 14.0-hour job
This is a 14.0 hour job, including the time required for disassembly and assembly, welding and hose assembly fabrication. A maximum of $50 will be allowed for time and materials to fabricate PLATE_001. A maximum of $150 will be allowed for time and materials to fabricate PLATE_002 if required.

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PARTS DISPOSITION

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

Rework Procedure

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Note: Trucks HRT00100-106, MN500052-54, MN500056, MT500102-107 and MT500112-154 will be configured as shown in Image 1.1.1. The configuration shown in Image 1.1.1 was effective in production with HRT00100 and MT500112. Trucks MN500052-54, MN500056 and MT500102-107 were updated as shown in Image 1.1.1 outside of the effective production serial numbers.

Note: Trucks MN500055, MT500100-101 and MT500108-111 are not configured as shown in Image 1.1.1. These trucks are not equipped with a 29 pin harness assembly interface connector (right side arrow) as shown in Image 1.1.1. Trucks are not required to complete Steps 7, 18 and 20. In addition, a portion of Steps 16 and 23 may not be required, or may require a modification to complete harness assembly routing using the parts identified in these steps. These steps would only be required if trucks were updated with the hydraulic and electrical retrofit update package.

1. Rework the electrical harness assembly connections on the right side of the rear axle housing shown in Image 1.1.1.

Image1.1.1

2. Remove components as required in affected rework area. Once the required components have been removed the rear axle mounting hardware on trucks should be configured as shown in Image 1.2.1. Remove four bosses as indicated in Image 1.2.1.

Note: Some trucks may have a different mounting arrangement of the harness assembly interface connections and may require the removal of some additional mounting hardware.

3. In order to reconfigure the wiring harness connections described in this rework procedure, the filter bracket as shown in Image 1.1.1 must be lowered approximately dimension (Y) 330 mm (13 inch) as shown in Image 1.2.1. Carefully cut off the filter bracket and save for reuse later.

Image1.2.1

4. Locate 9R-2672 Boss (1) from 442-2778 Block using dimension (A) 144 mm (5.67 inch) and dimension (B) 47.50 mm (1.87 inch) as shown in Image 1.3.1. Weld 9R-2672 Boss (1) all around with 3 mm (0.12 inch) fillet weld (W1).

5. Locate 8X-4903 Block (2) from 442-2778 Block using dimension (C) 222 mm (8.74 inch), dimension (D) 128.70 mm (5.10 inch), dimension (E) 175.30 mm (6.90 inch) and dimension (F) 130.25 mm (5.13 inch) as shown in Image 1.3.1. Weld 8X-4903 Block (2) all around with 5 mm (0.20 inch) fillet weld (W2).

Image1.3.1

6. Locate 127-3387 Boss (3) from 442-2778 Block using dimension (G) 83.80 mm (3.30 inch) and dimension (H) 34.67 mm (1.36 inch) as shown in Image 1.4.1. Weld 127-3387 Boss (3) all around with 5 mm (0.20 inch) fillet weld (W3).

7. Locate 9C-4935 Plate (4) from 442-2778 Block using dimension (J) 25.40 mm (1.00 inch), dimension (K) 79 mm (3.11 inch), dimension (L) 202.30 mm (7.96 inch) and dimension (M) 229.30 mm (9.03 inch) shown in Image 1.4.1. Weld 9C-4935 Plate (4) all around with 5 mm (0.20 inch) fillet weld (W4).

Image1.4.1

8. Locate 9R-2613 Boss (5) from 9R-2672 Boss (1) using dimension (N) 59 mm (2.32 inch) and dimension (P) 102 mm (4.02 inch) as shown in Image 1.5.1. Weld 9R-2613 Boss (5) all around with 3 mm (0.12 inch) fillet weld (W5).

Image1.5.1

9. Locate 4E-7829 Block (6) from 9R-2672 Boss (1) and 127-3387 Boss (3) using dimension (Z) 182.3 mm (7.18 inch), dimension (AA) 165.7 mm (6.52 inch), dimension (BB) 204.1 mm (8.03 inch) and dimension (CC) 363.7 mm (14.32 inch) as shown in Image 1.6.1. Weld 4E-7829 Block (6) all around with 5 mm (0.20 inch) fillet weld (W6).

Image1.6.1

10. Locate two 7Y-7259 Bosses (7) from edge of plate (FF) and edge of weld (GG) on rear axle housing using dimension (DD) dimension 251 mm (9.88 inch), dimension (EE) 482 mm (18.98 inch), dimension (FF) 123 mm (4.84 inch) and dimension (GG) 176 mm (6.93 inch) as shown in Image 1.7.1. Weld two 7Y-7529 Bosses (7) all around with 5 mm (0.20 inch) fillet weld (W7).

Image1.7.1

11. Locate 163-9662 Boss (8) using dimension (HH) 190 mm (7.48 inch) and dimension (JJ) 64 mm (2.52 inch) as shown in Image 1.8.1. Weld 163-9662 Boss (8) all around with 5 mm (0.20 inch) fillet weld (W8).

Image1.8.1

12. Locate two 9R-3761 Bosses (9) using dimension (KK) 388 mm (15.28 inch) and dash lines as shown in Image 1.9.1 and Image 1.9.2. Weld two 9R-3761 Bosses (9) all around with 3 mm (0.12 inch) fillet weld (W9).

NOTE: The first boss location for clipping 590-1993 Hose As (46) from rear wheel on most trucks is located as shown in Image 1.9.3 and not as existing boss as shown in Image 1.9.2. Existing boss does not require relocation for routing the hose assembly.

Image1.9.1

Image1.9.2

Image1.9.3

13. Fabricate PLATE_001 as shown in Image 1.10.1. Material is carbon steel with 170 MPa minimum yield strength.

Image1.10.1

14. If filter bracket that was removed in Step 3 is not salvageable, fabricated PLATE_002 as shown in Image 1.11.1. Material is carbon steel with 170 MPa minimum yield strength.

Image1.11.1

15. Locate filter bracket that was remove in Step 3 or PLATE_002 to PLATE_001 with 5 mm (0.20 inch) dimension as shown in Image 1.12.1. Weld filter bracket or PLATE_002 to PLATE_001 with 5 mm (0.20 inch) fillet weld (W10) from A to B, two places and from C to D, two places.

Image1.12.1

16. Install 193-5576 Bracket As (10) and two 204-8000 Mounts (13) to 127-3387 Boss (3) using one 8T-4196 Bolt (11) and one 8T-4121 Washer (12) as shown in Image 1.13.1. Install two 204-8000 Mounts (13) to other end of 193-5576 Bracket As (10) using one 8T-4196 Bolt (11) and one 8T-4121 Washer (12) as shown in Image 1.13.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

Image1.13.1

17. Install 3G-4005 Link (15) to 9R-2672 Boss (1) using one 8T-4137 Bolt (16) and one 8T-4121 Washer (12) as shown in Image 1.14.1. Install one 204-8000 Mount (13) to other end of 3G-4005 Link (15) using one 8T-4195 Bolt (17), two 8T-4121 Washers (12) and one 344-5675 Nut (18) as shown in Image 1.14.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

Image1.14.1

18. Install 397-9469 Bracket As (19) to 9C-4935 Plate (4) using two 8T-4137 Bolts (16) and two 8T-4121 Washers (12) as shown in Image 1.15.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft). Re-install 29 pin connector on harness assembly (LL) that was disconnected in Step 2, to 397-9469 Bracket As (19) using 211-0052 Nut (20). Tighten nut to 7.9 +/- 0.5 N.m (70 +/- 4 lb in).

19. Install 290-0001 Bracket As (21) to 8X-4903 Block (2) using two 8T-4137 Bolts (16) and two 8T-4121 Washers (12) as shown in Image 1.15.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft). Re-install 70 pin connector on harness assembly (MM) that was disconnected in Step 2, to 290-0001 Bracket As (21) using four 162-2165 Bolts (22), eight 8C-9660 Washers (23) and four 5C-8312 Nuts (24). Tighten four bolts to 1.7 +/- 0.4 N.m (15 +/- 4 lb in).

Image1.15.1

20. Install 398-1083 Bracket (25) to 397-9469 Bracket As (19) using four 8T-4137 Bolts (16) and four 8T-4121 Washers (12) as shown in Image 1.16.1. Tighten four bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

21. Install 290-0002 Bracket (26) to 290-0001 Bracket As (21) using two 8T-4137 Bolts (16) and two 8T-4121 Washers (12) as shown in Image 1.16.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

Image1.16.1

22. Install 350-1571 Bracket As (27) to 9R-2613 Boss (5) using 8T-4136 Bolt (28) and one 8T-4121 Washer (12) as shown in Image 1.17.1. Install two 204-8000 Mounts (13) to other end of 350-1571 Bracket As (27) using one 8T-4196 Bolt (11) and one 8T-4121 Washer (12) as shown in Image 1.17.1. Tighten two bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

Image1.17.1

23. Connect harness assembly (LL) and harness assembly (MM) breakouts to right wheel rear axle filter. Secure harness assembly (LL) to three 204-8000 Mounts (13) using three 204-2281 Straps (14) as shown in Images 1.13.1 and 1.17.1. Secure harness assembly (MM) to four 204-8000 Mounts (13) using four 204-2281 Straps (14) as shown in Images 1.13.1, 1.14.1 and 1.17.1.

NOTE: Fabricate a jumper harness as required to make existing harness assembly connection to 221-3415 Sensor Gp (3-pin connector) on filter housing. Use required length of 366-8856 Harness As, 155-2260 Connecting Plug Kit, 102-8803 Receptacle Kit, three 126-1767 Pins and three 126-1768 Sockets to fabricate jumper harness.

NOTE: Fabricate a jumper harness as required to make existing harness assembly connection to 391-7125 Sensor Gp (2-pin connector) on filter housing. Use required length of 366-8856 Harness As, 155-2270 Connecting Plug Kit, 102-8802 Receptacle Kit, two 126-1767 Pins and two 126-1768 Sockets to fabricate jumper harness. Secure and protect unused wire in harness assembly.

NOTE: Secure existing harness assembly breakouts and jumper harness as required using 7K-1181 Straps.

24. Install 583-4389 Plate As (29) to 442-2778 Block using four 8T-4195 Bolts (17) and four 8T-4121 Washers (12) as shown in Image 1.19.1. Tighten four bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

25. Re-install high volt cables to 583-4389 Bracket As (29) as shown in Image 1.19.1 using two blocks (NN), two blocks (PP), two plates (RR), four bolts (SS) and four washers (TT) that were removed in Step 2. Tighten four bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

Image1.19.1

26. Reinstall reconfigured filter bracket to 4E-7829 Block (6) using two 8T-4139 Bolts (30) and two 5P-1076 Washers (31) as shown in Image 1.20.1.Tighten two bolts to 100 +/- 20 N.m (74 +/- 15 lb ft).

Image1.20.1

27. Remove both 9X-8408 Connectors from filter housing. Install 138-7538 Adapter (32) using one 238-5084 Seal-O-Ring (33) and one 228-7091 Seal-O-Ring (34) as shown in Image 1.21.1. Tighten adapter to 350 +/- 53 N.m (258 +/- 39 lb ft). Install 6V-9852 Adapter (35) using one 228-7091 Seal-O-Ring (34) as shown in Image 1.21.1. Tighten adapter to 110 +/- 17 N.m (81 +/- 13 lb ft). Install 6V-9182 Adapter (36) using one 238-5084 Seal-O-Ring (33) and one 228-7092 Seal-O-Ring (37) as shown in Image 1.21.1. Tighten adapter to 350 +/- 53 N.m (258 +/- 39 lb ft). Install 8T-8899 Adapter (38) using one 228-7092 Seal-O-Ring (37) as shown in Image 1.21.1. Tighten adapter to 140 +/- 21 N.m (103 +/- 15 lb ft).

NOTE: The 138-7538 Adapter (32) and 6V-9182 Adapter (36) are not required for trucks equipped with 442-3295 Oil Cooler Lines Gp part of 442-2881 Rear Axle Cooling Arrangement. Do not remove the 9X-8408 Connector on the filter housing that is used with the 476-1817 Hose As.

28. Reinstall filter housing that was removed in Step 3 to filter bracket using existing filter housing mounting hardware. Tighten three bolts to 47 +/- 9 N.m (35 +/- 7 lb ft).

Image1.21.1

29. Remove 8T-5429 Adapter or 127-1647 Adapter from rear axle lubrication pump. Install 6V-9007 Adapter (39) using 238-5082 Seal-O-Ring (40) and one 228-7092 Seal-O-Ring (37) as shown in Image 1.22.1. Tighten adapter to 220 +/- 33 N.m (162 +/- 24 lb ft).

NOTE: This step is not required for trucks equipped with 442-3295 Oil Cooler Lines Gp part of 442-2881 Rear Axle Cooling Arrangement.

Image1.22.1

30. Remove and replace the 442-3440 Hose As part of 442-3268 Oil Cooler Lines Gp with 584-9665 Hose As (41) as shown in Image 1.23.1. Tighten both ends of hose assembly to 140 +/- 21 N.m (103 +/- 15 lb ft).

31. Assemble 584-9665 Hose As (41) using two 5P-7466 Clips (42), two 5P-7467 Clips (43), two 5P-8112 Grommets (44), two 8T-4139 Bolts (30) and two 8T-4223 Washers (45) as shown in Image 1.23.1. Tighten two bolts to 100 +/- 20 N.m (74 +/- 15 lb ft).

NOTE: This step is not required for trucks equipped with 442-3295 Oil Cooler Lines Gp part of 442-2881 Rear Axle Cooling Arrangement. The 442-3295 Oil Cooler Lines Gp is not equipped with a 442-3440 Hose As at this location. The 442-3295 Oil Cooler Lines Gp uses a 476-1817 Hose As at this location. The 476-1817 Hose As would need to be removed and replaced by a hose assembly that is approximately 304 mm to 356 mm (12 to 14 inches) longer.

Image1.23.1

32. Remove and replace the 442-3440 Hose As part of 442-3268 Oil Cooler Lines Gp or 442-3295 Oil Cooler Lines Gp with 590-1993 Hose As (46) as shown in Image 1.24.1. Assemble 590-1993 Hose As (46) using 6V-8639 Adapter (47), 238-5080 Seal-O-Ring (48), 228-7090 Seal-O-Ring (49). The 6V-8639 Adapter (47) replaces 8C-8989 Adapter. Tighten adapter to 100 +/- 15 N.m (74 +/- 11 lb ft). Tighten 90? coupling end of hose assembly to 65 +/- 10 N.m (48 +/- 7 lb ft). Tighten straight coupling end of hose assembly to 110 +/- 17 N.m (81 +/- 13 lb ft).

33. Assemble 590-1993 Hose As (46) using four 5P-7464 Clips (50), four 5P-7465 Clips (51), four 6V-1249 Grommets (52), one 8T-4192 Bolt (53), one 8T-4223 Washer, three 8T-4195 Bolts (17) and three 8T-4121 Washers (12) as shown in Image 1.24.1. Tighten one bolt to 100 +/- 20 N.m (74 +/- 15 lb ft). Tighten three bolts to 55 +/- 10 N.m (41 +/- 7 lb ft).

NOTE: The clips and or mounting hardware for the first clipping location from the rear wheel may not be needed if the hose assembly will share the clipping location with the brake lines group. The boss for the first clipping location may be an imperial (inch) thread and a 8T-4195 Bolt (17) and 8T-4121 Washer (12) can not be used. Instead, use a 5P-2228 Bolt and 7X-0584 Washer, which may be the existing mounting hardware at this location.

Image1.24.1

34. Apply Service Magazine M0109215, "Rear Wheel Traction Motor Air Cooling Flex Hose Retention is Improved on Certain 794 AC, 796 AC, and 798 AC Off-Highway Trucks" using the following parts:

2 x 7Y-2522 Plate
2 x 586-7996 Bracket
4 x 8T-4192 Bolt
4 x 5P-1076 Washer
12 x 8T-4121 Washer
4 x 6V-8801 Nut
4 x 563-5509 Bracket
4 x 1B-2706 Bolt
4 x 194-7882 Spacer
4 x 576-5522 Strip
4 x 091-9035 Spacer
4 x 344-5675 Nut
4 x 8T-4185 Bolt

35. Apply Service Magazine M0113332, "Traction Motor Air Cooling Duct Retention is Improved on Certain 794 AC, 796 AC, and 798 AC Off-Highway Trucks" using the following parts:

2 x 583-2100 Ring
8 x 3E-7447 Clamp