- Off-Highway Truck/Tractor
- 770G (S/N: TWA1-152; ECM1-354; ECX1-114)
- 772G (S/N: LTS1-422; LTX1-210)
Introduction
This special instruction contains information to install new alternator group and support group on the machines listed above
Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.
Reference: Disassembly and Assembly, UENR1120, Alternator - Remove and Install
Reference: Refer to Special Instruction, REHS1841, "General Welding Procedures"
Safety Section
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.
Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.
Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, ensure that it is safe for you and for others. Ensure that the product will not be damaged or made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.
Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Cat dealer for replacement manuals. Proper care is your responsibility.
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Do not attempt to assemble this machine until you read and you understand the assembly instructions. Improper assembly procedures could result in injury or death. |
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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on. |
Required Parts
| Required Parts | ||
| Item | Qty | Description |
| 1 | 2 | 0T-0573 Bolt |
| 2 | 5 | 5M-2894 Hard Washer |
| 3 | 1 | 489-0273 Support Bracket |
| 4 | 1 | 101-8917 Taperlock Stud |
| 5 | 1 | 9S-8752 Full Nut |
| 6 | 2 | 0S-1608 Bolt |
| 7 | 1 | 279-2589 Idler Pulley (non A/C unit only) |
| 8 | 4 | 7X-2543 Bolt |
| 9 | 9 | 8T-4121 Hard Washer |
| 10 | 8 | 8T-4222 Plated Washer |
| 11 | 4 | 6N-8744 Mount |
| 12 | 4 | 344-5675 Nut |
| 13 | 1 | 329-8797 Belt Tensioner |
| 14 | 1 | 8T-0643 Bolt |
| 15 | 1 | 331-9604 Serpentine Belt |
| 16 | 4 | 7X-2539 Bolt |
| 17 | 4 | 8T-4224 Hard Washer |
| 18 | 1 | 506-3240 Boss As |
| 19 | 1 | 438-9723 Plate |
| 20 | 1 | 351-6508 Serpentine Belt (Non A/C unit only) |
| 21 | 1 | 454-7658 Bracket As |
| 22 | 2 | 8T-2502 Bolt |
| 23 | 2 | 5P-1075 Hard Washer |
| 24 | 3 | 067-2551 Clip |
| 25 | 3 | 353-7957 Grommet |
| 26 | 1 | 8T-4195 Bolt |
| 27 | 1 | 493-4499 Guard |
| 28 | 3 | 305-5385 Bolt |
| 29 | 3 | 342-4447 Insert |
| 30 | 3 | 198-4776 Hard Washer |
| 31 | 1 | 8T-0389 Locknut |
| 32 | 1 | 8T-4137 Bolt |
| 33 | 1 | 8T-4136 Bolt |
| 34 | 1 | 527-5948 Cable As |
| 35 | 1 | 269-4983 Bracket As |
Machine Preparation
- Move the machine to a safe and smooth location.
- Turn front wheels to the left for easy access to the alternator.
- Move the transmission control to the Park position
- Shut off engine and main disconnect switch.
- Place blocks in front of the wheels and behind the tires.
Installation Procedure
- Remove and save existing belt guard, alternator guard, and mounting hardware.
- Remove and save existing alternator, accessory support bracket, refrigerant compressor, and lower belt guard support bracket.
Reference: Refer to Disassembly and Assembly, REN8261, Alternator - Remove and Install
- Remove and save the crankshaft pulley and dampener.
- Remove and discard two studs that were used to secure the existing support bracket to the front of the engine.
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Illustration 1 g06220613 View of front of the engine
(1)0T-0573 Bolt
(2)5M-2894 Hard Washer
(3)489-0273 Support Bracket
(4)101-8917 Taperlock Stud
(5)9S-8752 Full Nut
(9)8T-4121 Hard Washer
(13)329-8797 Belt Tensioner
(14)8T-0643 Bolt - Install Taper lock stud (4) into the front cover. Tighten stud (4) to
35 ± 5 N·m (26 ± 4 lb ft) . - Install Front Engine Accessory Drive (FEAD) support bracket (3) to front of engine with two bolts (1), two bolts (6), five hard washers (2), and nut (5). Tighten bolts to
47 ± 9 N·m (35 ± 7 lb ft) - Install belt tensioner (13) with bolt (14) and hard washer (9). Tighten the bolt to
55 ± 10 N·m (40 ± 7 lb ft) Show/hide table
Illustration 2 g06220929 View of front of engine - Reinstall crankshaft pulley and dampener.
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Illustration 3 g06223502 View of compressor group
(A) Refrigerant compressor group
(B) Belt guard support bracket
(3)489-0273 Support Bracket
(16)7X-2539 Bolt
(17)8T-4224 Hard Washer - If the machine has air conditioning, then reinstall refrigerant compressor group (A) along with belt guard support bracket (B) to support bracket (3) using four bolts (16), and four hard washers (17). Tighten bolts to
28 ± 7 N·m (20 ± 5 lb ft) .Show/hide table
Illustration 4 g06223779 View of idler pulley attachment
(B) Belt guard support bracket
(C) Existing bolts
(3)489-0273 Support Bracket
(7)279-2589 Idler Pulley - If the machine does not have an existing refrigerant compressor group, then install idler pulley (7) in the lower right boss of support bracket (3). Attach the existing belt guard support bracket (B) to the bottom of support bracket (3) using existing hardware (C) retained earlier.
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Illustration 5 g06224149 View of front of the engine.
(3)489-0273 Support Bracket
(8)7X-2543 Bolt
(9)8T-4121 Hard Washer
(10)8T-4222 Plated Washer
(11)6N-8744 Mount
(12)344-5675 Nut - Assemble charging alternator group (D) to support bracket (3) using four bolts (8), four hard washers (9), eight plated washers (10), four mounts (11), and four nuts (12). Tighten the bolts to
55 ± 10 N·m (40 ± 7 lb ft) .Note: Apply 207-1601 Rubber Lubricant to mount (11) before sliding the mounts into position in bracket (3).
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Illustration 6 g06224290 - Mount plate (19) onto charging alternator group (D) using top rear bolt (8) and one hard washer (9). Refer to Illustration 6 for orientation of plate (19.)
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Illustration 7 g06224316 Belt routing
(C) Crankshaft
(T) Tensioner
(A) Alternator
(I) Idler
(A/C) Refrigerant compressor
(15)331-9604 Serpentine Belt
(20)351-6508 Serpentine Belt - Install serpentine belt (15) for machines with A/C attachment.
Install serpentine belt (20) for machines without A/C.
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Illustration 8 g06224617 front view of engine compartment
(3)489-0273 Support Bracket
(21)454-7658 Bracket As
(22)8T-2502 Bolt
(23)5P-1075 Hard Washer - Mount bracket (21) into the top mounting holes on support bracket (3) using two bolts (22) and two hard washers (23). Tighten the bolts to
47 ± 9 N·m (35 ± 6 lb ft) Show/hide table
Illustration 9 g06224653 View of assembled guard
(27)493-4499 Guard
(28)305-5385 Bolt
(29)342-4447 Insert
(30)198-4776 Hard Washer - Assemble guard (27) to the guard mounting brackets using three bolts (28), three inserts (29), and three hard washers (30). Tighten the bolts to
26 ± 7 N·m (19 ± 5 lb ft) .Note: Verify that there is ample clearance for the ATAAC tube, dampener guard, and alternator before fully tightening the fasteners.
- Prepare the machine for welding. Remove any dirt, oil, debris, or paint from welding areas. Refer to Special Instruction, REHS1841, General Welding Procedures prior to performing any welding on the machine.
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Illustration 10 g06225310 View of underside of cab support
(18)125-5006 Boss As
(W1) 5mm fillet weld
(E)70 mm (2.8 inch)
(F)25.4 mm (1 inch) - Locate and weld boss assembly (18) as per the dimension shown in Illustration 10.
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Illustration 11 g06225348 View of underside of cab support
(9)8T-4121 Hard Washer
(18)125-5006 Boss As
(24)067-2551 Clip
(25)353-7957 Grommet
(32)8T-4137 Bolt
(33)8T-4136 Bolt
(34)527-5948 Cable As
(35)269-4983 Bracket As - Secure ground cable (34) to ground boss (18) using bolt (33) and hard washer (9). Tighten the bolt to
55 ± 10 N·m (41 ± 7 lb ft) . - Mount bracket (35) to the brake line support boss using the existing hardware.
Note: Do not fully tighten the hardware until ground cable (34) is installed.
- Attach ground cable (34) to bracket (35) using clip (24), grommet (25), bolt (32), and hard washer (9). Tighten all the bolts to
55 ± 10 N·m (41 ± 7 lb ft) .Show/hide table
Illustration 12 g06225351 View of the Alternator
(9)8T-4121 Hard Washer
(19)438-9723 Plate
(24)067-2551 Clip
(25)353-7957 Grommet
(26)8T-4195 Bolt
(31)8T-0389 - Connect electrical harness leads to the back of the alternator. Secure the leads to plate (19) with two clips (24), two grommets (25), two hard washers (9), one bolt (26), and one nut (31). Refer to Illustration 12 for orientation of clip (24).
- Place machine back into service.
