Usage:
CONFIDENTIAL TIBU4358-02
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TECHNICAL INFORMATION BULLETIN |
FEBRUARY 16, 2005 |
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EXCAVATORS |
THIS TIB REPLACES THE NOVEMBER 24, 2004 EXCAVATORS TIB (TIBU4358-01), COMPONENT CODES 4151, 7062, THE WELDS THAT JOIN THE CARBODY FRAME AND THE TRACK ROLLER FRAME MAY CRACK ON CERTAIN EXCAVATORS. DESTROY THE NOVEMBER 24, 2004 TIB. 320C (FBA, GHA, MAA, BCB, MAB, AMC, FBC, CCD, BEF, AKH, BPR), 320C U (APA, FBB, MAC, CLM), |
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Component Code(s) 4151, 7062 |
SUBJECT: THE WELDS THAT JOIN THE CARBODY FRAME AND THE TRACK ROLLER
FRAME MAY CRACK ON CERTAIN EXCAVATORS
PROBLEM:
Reports from the field indicate that the welds that join the carbody frame and the track roller frame may crack. The cracked welds are related to the severity of the underfoot conditions. The bottom plate of the carbody is usually dented from contact with rock or other hard objects. Cracks that are present in the welds may expand and weaken the structural integrity of the frame.
SOLUTION:
If cracks are present in the welds that join the carbody frame and the track roller frame, remove the cracks and repair with new welds. Use the information that follows for the repair of the cracked welds.
NOTE: Use the following repair procedure only after cracks are present in the welds. Do not use the following repair procedure for reinforcement of the frame before cracks in the welds are present.
Repair Instructions For Cracked Welds
Before making weld repairs, refer to the Operation and Maintenance Manual that is appropriate for your machine. Lift one side of the machine. If a cracked weld extends into the inner side of the track frame body, remove the track assembly and the track rollers. Support the machine with a repair stand.
Illustration 1. Typical Frame Assembly
Illustration 2. Detail B Of View A-A In Illustration 1.
(C) Cracked Weld Typical In Four Places
Examine the crack and the toe of the weld. Examine the shape of the weld. The weld is unsymmetrical, if the size of the weld on the carbody frame is larger than the size of the weld on the track roller frame. If the toe of the weld overlaps the side of the track frame body, the probability of cracks and lack of weld penetration is high. If there is cold lap or lack of weld penetration, the weld should be gouged out.
Use the following information if no cracks are present and only the cold lap condition exists.
- Gouge out the toe of the weld until the line of no penetration is removed.
Use the following information if cracks are present.
- Install backup strips on the backside of the cracked area as shown in Illustration 4. The size of the backup strips is listed in Table 1.
- Gouge out the cracked weld from the carbody side and completely remove the crack. On the cracked frame side, gouge out the cracked weld to a depth that will remove the area of the weld penetration from the original weld. Refer to Illustration 3.
Illustration 3. Detail B Of View A-A In Illustration 1.
(D) Area To Be Gouged Out
Use the following information if the length of the crack is less than 100 mm (4 inch).
- Install backup strips on the backside of the cracked area as shown in Illustration 4. The size of the backup strips is listed in Table 1
- Manufacture the required backup strips for your machine. Refer to Table 1 for backup strip dimensions.
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Backup Strips For 320C (APA, FBA, MAA, BCB, FBB, AKH, ALX) Excavators |
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Qty |
Length |
Width |
Thickness |
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4 |
598 mm (23.5 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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186 mm (7.3 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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33 mm (1.3 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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Backup Strips For 320C (GHA, MAB, AMC, FBC, MAC, CCD, BEF, CLM, BPR) Excavators |
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4 |
598 mm (23.5 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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186 mm (7.3 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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33 mm (1.3 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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Backup Strips For 320C (PAA, ALF, ALX) Excavators |
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4 |
598 mm (23.5 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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130 mm (5.1 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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83 mm (3.3 inch) |
25 mm (1.0 inch) |
9 mm (0.3 inch) |
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Backup Strips For 320C (ANB, BDB, BGB, PAB, BBC, GAC, HBC, PAC, SAH, BKK, BER, TBR, BRX) Excavators |
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4 |
598 mm (23.5 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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130 mm (5.1 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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83 mm (3.3 inch) |
25 mm (1.0 inch) |
10 mm (0.4 inch) |
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Table 1.
Illustration 4. Detail B Of View A-A In Illustration 1.
(E) Backup strip
Illustration 5. Backup Strip Location On A Standard Track Roller Frame
(1) Backup strip 33 mm (1.3 inch) long
(2) Backup strip 186 mm (7.3 inch) long
(3) Backup strip 598 mm (23.5 inch) long
(A) 191.5 mm (7.5 inch)
(B) 10 mm (0.4 inch)
(C) 12 mm (0.5 inch)
Illustration 6. Backup Strip Location On A Long Track Roller Frame
(1) Backup strip 83 mm (3.3 inch) long
(2) Backup strip 130 mm (5.1 inch) long
(3) Backup strip 598 mm (23.5 inch) long
(A) 191.5 mm (7.5 inch)
(B) 10 mm (0.4 inch)
(C) 12 mm (0.5 inch)
Illustration 7. Repair Weld
(H) 5 mm (0.2 inch) Radius
Illustration 8. Gusset
(J) 13 mm (0.5 inch)
(K) 75 mm (3.0 inch)
(L) 25 mm (1.0 inch)
(M) 18 mm (0.7 inch)
(N) 165 mm (6.5 inch)
(R) 10?
(S) 100 mm (4 inch) Radius
Illustration 9. Typical Frame Assembly
(T) 629 mm (24.75 inch) For Standard Undercarriage And For Long Undercarriage
(U) 635 mm (25.05 inch) For Standard Undercarriage And 716 mm (28.25 inch) For Long Undercarriage
Illustration 10.
(V) 16 mm (0.63 inch)
(W) 14 mm (0.55 inch)
Illustration 11. Typical Location Of Tack Welds
(X) 50 mm (2 inch) Tack Weld
If the cracked weld extends the entire length of the weld joint, tack welds must be added in order to prevent deformation during the repair. The repair weld for the entire length should be completed as two separate welds. Each weld will repair approximately one half of the entire length.
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