- Off-Highway Truck:
- 793C (S/N: 4AR76-424; ATY183-1124; 4GZ93-264)
- 793C XQ (S/N: CBR93-108)
Introduction
This Special Instruction explains the installation of the improved walkways on the 793C and 793C XQ Off-Highway Trucks. Do not begin the installation until you have read the information that is contained in this instruction.
Safety
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Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas. |
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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of LaborWashington, D.C. 20210 |
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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 in order to perform these functions properly.
ReferenceRefer to the Special Instruction, REHS1841, "General Welding Procedures" when you perform any welding procedures during this instruction, as needed.
Needed Parts
The required parts for the field installation of the improved walkways are listed in Table 1.
Required Part for the Installation of the Improved Walkways     | ||
Qty     | Part Number     | Description     |
1     | 272-5431     | Walkway Gp     |
1     | 275-3519     | Walkway Gp     |
10     | 5S-7379     | Bolts     |
46     | 5P-1075     | Hard Washer     |
10     | 4L-6454     | Bolts     |
20     | 5P-8167 (1) 5M-3062 (2) 5S-7379 (3)     |
Bolts     |
16     | 2H-3855     | Bolts     |
16     | 5P-8245     | Hard Washers     |
3     | 8T-2502     | Bolts     |
3     | 6V-8801     | Nuts     |
6     | 8T-4896     | Hard Washers     |
1     | 290-6591     | Brace     |
6     | 5S-7382     | Bolts     |
1     | 301-0964     | Handrail As     |
35     | 8T-4136     | Bolts     |
47     | 8T-4121     | Hard Washers     |
4     | 8T-4956     | Bolts     |
4     | 8T-4223     | Hard Washers     |
4     | 8T-4194     | Bolts     |
5     | 198-4778     | Hard Washers     |
1     | 242-9814     | Handrail As     |
1     | 250-7605     | Bracket As     |
8     | 8T-4182     | Bolts     |
1     | 134-0987     | Bracket As     |
2     | 134-0989     | Blocks     |
4     | 8T-4186     | Bolts     |
1     | 8T-4185     | Bolt     |
1     | 7X-7729     | Washer     |
1     | 8T-4133     | Nut     |
3     | 8T-3490     | Weld Nuts     |
( 1 ) | Use this bolt when no shims are needed. |
( 2 ) | Use this bolt when one shim is needed. |
( 3 ) | Use this bolt when two shims are needed. |
Required Tooling
Required Tools     | |||
---|---|---|---|
Item     | Qty     | Tool Number     | Description     |
AA     | 1     | -     | Hand Grinder     |
-     | Numerous     | -     | Cables Chains Hooks Shackles     |
Specifications for Cables, Chains, and Lifting Devices
Use approved cables, chains, and lifting devices in order to lift components. Refer to the manufacturer's weight's in order to determine the application when you select the following items: cable, chain and lifting devices. When you lift a component, the lift angle is critical. Refer to the Illustration that follows in order to see the effect of the lift angle on the working load limit.
Note: The lifting devices that are shown in this publication are not AVSpare parts.
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Illustration 1 | g00629745 |
Lift angles for lifting slings. (A) The load capacity is 100% of the working load limit for the sling. (B) The load capacity is 86% of the working load limit for the sling. (C) The load capacity is 70% of the working load limit for the sling. (D) The load capacity is 50% of the working load limit for the sling. |
Fabrication of the Required Parts
Fabricate all parts out of plain carbon steel.
Fabrication of the Required Blocks
- Fabricate two blocks (A) to the given dimensions.
B ... 20 mm (0.8 inch)
C ... 10 mm (0.4 inch)
D ... 41 mm (1.61 inch)
E ... 70 mm (2.8 inch)
F ... 125 mm (5.0 inch)
G ... 40 mm (1.60 inch)
(H) Two 8.2 + 0.30 - 0.10 mm (0.323 + 0.012 - 0.004 inch) holes with 3/8-16-2B threads
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Illustration 2 | g01404058 |
- Fabricate eight blocks (J) to the given dimensions.
K ... 10 mm (0.4 inch)
L ... 10 mm (0.4 inch)
M ... 26 mm (1.024 inch)
N ... 64 mm (2.52 inch)
P ... 101 mm (4.0 inch)
R ... 38 mm (1.5 inch)
(S) Two 8.2 + 0.30 - 0.10 mm (0.323 + 0.012 - 0.004 inch) holes with 3/8-16-2B threads
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Illustration 3 | g01404059 |
Fabrication of the Required Shims
- Fabricate shims (T) to the given dimensions.
U ... 20 mm (0.8 inch)
V ... 3 mm (0.12 inch)
W ... 41 mm (1.61 inch)
X ... 70 mm (2.8 inch)
Y ... 125 mm (5.0 inch)
Z ... 40 mm (1.60 inch)
(BB) Two 11 + 0.30 - 0.10 mm (0.4331 + 0.012 - 0.004 inch) holes
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Illustration 4 | g01404063 |
- Fabricate shims (CC) to the given dimensions.
DD ... 10 mm (0.4 inch)
EE ... 3 mm (0.12 inch)
FF ... 26 mm (1.024 inch)
GG ... 64 mm (2.52 inch)
HH ... 101 mm (4.0 inch)
JJ ... 38 mm (1.5 inch)
(KK) Two 11 + 0.30 - 0.10 mm (0.4331 + 0.012 - 0.004 inch) holes
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Illustration 5 | g01404065 |
Fabrication of the New Fender Brace
- Fabricate tube (LL) .
MM ... 42.2 mm (1.66 inch)
NN ... 350 mm (13.78 inch)
PP ... 363 mm (14.30 inch)
(RR) 3.56 mm (0.14 inch)
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Illustration 6 | g01404066 |
- Weld a plug in the straight end of tube (LL) .
- Fabricate plate (SS) .
TT ... 20 mm (0.79 inch)
UU ... 15 mm (0.60 inch)
VV ... 13.5 mm (0.53 inch)
WW ... 13.5 mm (0.53 inch)
XX ... 60 mm (2.36 inch)
YY ... 10 mm (0.40 inch)
ZZ ... 50 mm (1.97 inch)
AB ... 2 X 5 mm (0.20 inch)
AC ... 42.2 mm (1.66 inch)
AD ... 13 mm (0.51 inch)
AE ... 68.2 mm (2.685 inch)
AF ... 125 mm (5.0 inch)
AG ... 6 mm (0.24 inch)
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Illustration 7 | g01404068 |
Side view |
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Illustration 8 | g01404070 |
Rear view |
- Weld plate (SS) onto tube (LL) .
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Illustration 9 | g01404071 |
(W1) 3 mm (0.12 inch) Fillet weld |
Removal of the Existing Parts
- Remove nine bolts (A) and nine washers (B) in order to remove fender (C). Use a suitable lifting device in order to assist in lifting fender (C). Retain all parts.
Note: Fender (C) weighs approximately 48 kg (106 lb).
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Illustration 10 | g01391648 |
- Remove three bolts (D), three washers (E), and three nuts (F) in order to remove mirror (G). Retain mirror (G) .
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Illustration 11 | g01391782 |
- Use a suitable lifting device in order to assist in lifting handrail (K) .
Note: Handrail (K) weighs approximately 18 kg (40 lb).
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Illustration 12 | g01391794 |
- Remove twelve bolts (H) and twelve washers (J) in order to remove handrail (K) .
- Remove twenty bolts (L) and twenty washers (M) in order to remove handrail (N). Use a suitable lifting device in order to assist in lifting handrail (N) .
Note: Handrail (N) weighs approximately 53.5 kg (118 lb).
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Illustration 13 | g01391813 |
- Attach a suitable lifting device (P) to walkway (R) in order to lift walkway (R) .
Note: Walkway (R) weighs approximately 135 kg (300 lb).
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Illustration 14 | g01404072 |
- Remove 36 bolts (S) and 36 washers (T) in order to remove walkway (R) .
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Illustration 15 | g01404073 |
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Illustration 16 | g01404074 |
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Illustration 17 | g01404075 |
- Use lifting device (P) in order to remove walkway (R) from the truck.
- Attach a suitable lifting device to air cleaner (U) in order to lift air cleaner (U) .
Note: Air cleaner (U) weighs approximately 204 kg (450 lb).
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Illustration 18 | g01404076 |
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Illustration 19 | g01404077 |
Front left hand view |
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Illustration 20 | g01404078 |
Front side view |
- Loosen clamps (V) and clamp (W) in order to remove air cleaner (U) .
- Remove four bolts (X) and four washers (Y). Retain all parts.
- Remove four bolts (Z) and four washers (BB). Retain all parts.
- Remove air cleaner (U) from the truck.
Modifications
Cab Modifications
- Use grinder (AA) in order to remove block (A) and block (B) from the bottom of the cab.
Note: After you remove block (A) and block (B), grind the area until the area is smooth.
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Illustration 21 | g01393754 |
View of the left side of the cab |
- Use grinder (AA) in order to remove block (C) from the bottom of the cab.
Note: After you remove block (C), grind the area until the area is smooth.
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Illustration 22 | g01393758 |
View of the front of the cab |
Modifications to the Air Cleaner
- Use the given measurements in order to mark the air cleaner.
Note: The given measurements are the center of the notches that are needed.
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Illustration 23 | g01394765 |
Rear view of the air cleaner (D) 281 mm (11.063 inch) (E) 287 mm (11.30 inch) |
- Cut a slot of 25 mm (0.98 inch) by 25 mm (0.98 inch) in two places from the top rear of the air cleaner.
Modifications to the Fender
Required Parts for Modification to the Fender     | |||
Item     | Qty     | Part Number     | Description     |
1     | 1     | 8T-4185     | Bolt     |
2     | 1     | 8T-4121     | Hard Washer     |
3     | 1     | 198-4778     | Hard Washer     |
4     | 1     | 7X-7729     | Washer     |
5     | 1     | 8T-4133     | Nut     |
- Mark measurement (F) and measurement (G) .
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Illustration 24 | g01395154 |
(F) 520 mm (20.5 inch) (G) 507 mm (19.96 inch) |
- Scribe a line between mark (F) and mark (G) .
- Cut along the scribed line in order to remove fender support (H) .
- Enlarge slot (J) .
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Illustration 25 | g01395187 |
(K) 14.5 mm (0.60 inch) |
- Mark measurement (L), measurement (M), and measurement (N) .
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Illustration 26 | g01395198 |
(L) 703 mm (27.7 inch) (M) 75 mm (3.0 inch) (N) 64 mm (2.52 inch) |
- Scribe a line between mark (M) and mark (N) .
- Cut fender (P) along the scribed line.
- Cut radius (R) and radius (S) from fender (P) .
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Illustration 27 | g01404079 |
(R) 15 mm (0.60 inch) (S) 15 mm (0.60 inch) |
- Scribe a line from measurement (L) to mark (T) .
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Illustration 28 | g01404080 |
- Cut fender (P) along the scribed line. Stop the cut once you reach radius (S) .
- Attach the new fender brace (U) that was fabricated in the ""Fabrication of the Required Fender Brace" " section. Use bolt (1), washer (2), washer (3), washer (4), and nut (5) in order to install fender brace (T) to fender (P) .
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Illustration 29 | g01404081 |
- Position fender brace (U) firmly against fender (P) .
- Weld fender brace (U) to fender (P) .
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Illustration 30 | g01404082 |
(W1) 3 mm (0.12 inch) Double side fillet weld |
Installation of the Improved Walkways
Required Part for the Installation of the Improved Walkways     | |||
Item     | Qty     | Part Number     | Description     |
1     | 1     | 272-5431     | Walkway Gp     |
2     | 1     | 275-3519     | Walkway Gp     |
3     | 8     | -     | Blocks     |
4     | 10     | 5S-7379     | Bolts     |
5     | 46     | 5P-1075     | Hard Washer     |
6     | 10     | 4L-6454     | Bolts     |
7     | -     | -     | Shim     |
8     | 2     | -     | Blocks     |
9     | 20     | 5P-8167 (1) 5M-3062 (2) 5S-7379 (3)     |
Bolts     |
10     | 16     | 2H-3855     | Bolts     |
11     | 16     | 5P-8245     | Hard Washers     |
12     | 3     | 8T-2502     | Bolts     |
13     | 3     | 6V-8801     | Nuts     |
14     | 6     | 8T-4896     | Hard Washers     |
15     | -     | -     | Shim     |
16     | 1     | 290-6591     | Brace     |
17     | 6     | 5S-7382     | Bolts     |
18     | 1     | 301-0964     | Handrail As     |
19     | 35     | 8T-4136     | Bolts     |
20     | 47     | 8T-4121     | Hard Washers     |
21     | 4     | 8T-4956     | Bolts     |
22     | 4     | 8T-4223     | Hard Washers     |
23     | 4     | 8T-4194     | Bolts     |
24     | 4     | 198-4778     | Hard Washers     |
25     | 1     | 242-9814     | Handrail As     |
26     | 1     | 250-7605     | Bracket As     |
27     | 8     | 8T-4182     | Bolts     |
28     | 1     | 134-0987     | Bracket As     |
29     | 2     | 134-0989     | Blocks     |
30     | 4     | 8T-4186     | Bolts     |
31     | 3     | 8T-3490     | Weld Nuts     |
( 1 ) | Use this bolt when no shims are needed. |
( 2 ) | Use this bolt when one shim is needed. |
( 3 ) | Use this bolt when two shims are needed. |
- Use sixteen bolts (9) and sixteen washers (5) in order to install blocks (3) to walkway (1). Block (3) was fabricated in Step 2 of the ""Fabrication of the Required Blocks" " section.
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Illustration 31 | g01394133 |
Top view of walkway (1) |
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Illustration 32 | g01394134 |
- Use a suitable lifting device in order to position walkway (1) to the truck.
Note: Walkway (1) weighs approximately 94 kg (207 lb).
- Install walkway (1) to the truck with ten bolts (4) and ten washers (5) .
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Illustration 33 | g01394183 |
- Install walkway (1) to the truck with ten washers (5) and ten bolts (6) .
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Illustration 34 | g01394209 |
- Use two bolts (9) in order to hold block (3) against the bottom of the truck cab. Measure the gap between block (3) and walkway (1).
Note: Use Table 5 in order to keep a record of the gap between block (3) and walkway (1). This information will be used to assist in installing the correct number of shims (7). Shims (7) were fabricated in Step 2 of the ""Fabrication of the Required Shims" " section.
Show/hide tableTable 5 Block     Measured Gap     1         2         3         4         5         6         7         8        
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Illustration 35 | g01394232 |
View of the bottom side of walkway (1) |
- Tack weld block (3) to the bottom side of the truck cab.
- Repeat Step 5 through Step 6 for the seven remaining blocks (3) .
- Use a suitable lifting device in order to lift walkway (1) .
Note: Walkway (1) weighs approximately 94 kg (207 lb).
- Remove sixteen bolts (9) and sixteen washers (5) that were installed in Step 1. Retain all hardware.
- Remove ten bolts (4), ten bolts (6), and twenty washers (5) that were installed in Step 3 and Step 4. Retain all hardware.
- Remove walkway (1) from the truck.
- Weld block (3) to the bottom side of the truck cab.
Note: Ensure that you only weld along the long side of block (3) .
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Illustration 36 | g01394356 |
(W1) 6 mm (0.24 inch) Double side fillet weld |
- Repeat Step 12 for the seven remaining blocks (3) .
- Use a suitable lifting device in order to position walkway (1) to the truck.
Note: Walkway (1) weighs approximately 94 kg (207 lb).
- Reinstall ten bolts (4), ten bolts (6), and twenty washers (5) that were removed in Step 10.
- Install the correct number of shims (7) that was measured in Step 5.
- Repeat Step 16 for the remaining seven blocks (3) .
- Reinstall sixteen bolts (9) and sixteen washers (5) that were removed in Step 9.
- Use four bolts (9) and four washers (5) in order to install blocks (8) to walkway (2). Blocks (8) were fabricated in Step 1 of the ""Fabrication of the Required Blocks"
" section.
Note: Make sure that the orientation of block (8) is correct. Refer to Illustration 38.
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Illustration 37 | g01394405 |
Top view of walkway (2) |
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Illustration 38 | g01394531 |
- Use a suitable lifting device in order to position walkway (2) to the truck.
Note: Walkway (2) weighs approximately 42 kg (93 lb).
- Install walkway (2) to the truck with sixteen bolts (10) and sixteen washers (11) .
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Illustration 39 | g01394536 |
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Illustration 40 | g01394537 |
- Secure walkway (1) to walkway (2) with three bolts (12), three nuts (13), and six washers (14) .
Note: Ensure that both surfaces of the walkways are flush with each other in order to avoid trip hazards.
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Illustration 41 | g01394538 |
- Use two bolts (9) in order to hold block (8) against the bottom of the truck cab. Measure the gap between block (8) and walkway (2) .
Note: Use Table 6 in order to keep a record of the gap between block (8) and walkway (2). This information will be used to assist in installing the correct number of shims (15). Shims (15) were fabricated in Step 1 of the ""Fabrication of the Required Shims" " section.
Show/hide tableTable 6 Block     Measured Gap     1         2        
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Illustration 42 | g01394602 |
- Tack weld block (8) to the bottom side of the truck cab.
- Repeat Step 23 through Step 24 for the one remaining block (8) .
- Weld block (8) to the bottom side of the truck cab.
Note: Ensure that you only weld along the short side of block (8) .
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Illustration 43 | g01394575 |
(W2) 6 mm (0.24 inch) Double side fillet weld |
- Repeat Step 26 for the one remaining block (8) .
- Remove four bolts (9) and four washers (5) that were installed in Step 19. Retain all hardware.
- Install the correct number of shims (15) that were measured in Step 23. Install shims (15) between walkway (2) and block (8) .
- Repeat Step 29 for the one remaining block (8) .
- Reinstall four bolts (9) and four washers (5) that were removed in Step 28.
- Use a suitable lifting device in order to lift air cleaner (A) that was removed in Step 9 of the ""Removal of the Existing Parts"
" section.
Note: Air cleaner (A) weighs approximately 204 kg (450 lb).
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Illustration 44 | g01394813 |
Front left hand view |
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Illustration 45 | g01394815 |
Front side view |
- Install clamps (B) and clamp (C) that was removed in Step 10 of the section ""Removal of the Existing Parts" " in order to secure air cleaner (A) .
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Illustration 46 | g01404210 |
- Install four bolts (D) and four washers (E) that were removed in Step 11 of the ""Removal of the Existing Parts" " section in order to secure air cleaner (A) .
- Install four bolts (F) and four washers (G) that were removed in Step 12 of the ""Removal of the Existing Parts" " section in order to secure air cleaner (A) .
- Use a suitable lifting device in order to lift fender (H) that was removed in Step 1 of the ""Removal of the Existing Parts"
" section.
Note: Fender (H) weighs approximately 48 kg (106 lb).
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Illustration 47 | g01394845 |
- Install nine bolts (J) and nine washers (K) that were removed in Step 1 of the ""Removal of the Existing Parts" " section in order to secure fender (H) .
- Remove four bolts (9), two bolts (6), and six washers (5). Retain washers (5) .
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Illustration 48 | g01431357 |
- Install brace (16) with six bolts (17) and six washers (5) .
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Illustration 49 | g01394863 |
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Illustration 50 | g01431363 |
- Install handrail (18) with sixteen bolts (19), sixteen washers (20), four bolts (21), four washers (22), four bolts (23), and four washers (24) .
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Illustration 51 | g01394895 |
- Install handrail (25) with sixteen bolts (19) and sixteen washers (20) .
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Illustration 52 | g01394988 |
- Install bracket (26) with eight bolts (27) and eight washers (20) .
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Illustration 53 | g01394993 |
- Install bracket (28) with two blocks (29), four bolts (30), and four washers (20) .
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Illustration 54 | g01394995 |
- Use three bolts (19), three washers (20), and three weld nuts (31) in order to reinstall mirror (L) that was removed in Step 2 of the ""Removal of the Existing Parts" " section.
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Illustration 55 | g01394999 |