TRANSMISSION AR 8E7594 - Caterpillar

Verify that the throat size of the fillet weld was not adversely affected after the TTD process as shown in Illustration 7.
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Example of an undercut gage
Use an undercut gage to determine the amount of weld undercut. Maximum Depth Measured from plate surface not to exceed 5 mm (0.2 inch). Refer to Illustration 8
Visually inspect for any types of weld discontinuities. Any visible discontinuities found in the TTD weld should be removed completely and the weld repaired.Typical TIG Toe Weld Defects and Repairs
Radius Less Than Design Requirements: Redress the weld toe using a slight weave technique as previously described.
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Example where transition to the base metal is not smooth (1) Base metal (2) TTD weld bead radius (3) Fillet weld (4) This area may be ground before TTD is applied
Transition of TTD Weld to the Base Plate Is Not Smooth, Refer to Illustration 9: Redress the weld bead without filler metal. Grinding some of the TTD may be necessary to remove the excess weld metal.
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Example of undersized weld throat after TTD (D) Normal weld throat (5) Throat undersized after TTD
Transition of the TTD to the Weld Face Causes the Throat of the Fillet to Be Undersized, Refer to Illustration 10: Reweld the undersize area with the TTD process adding filler wire if needed, or weld with the original welding process.
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Example of a weld undercut (6) Undercut
A TTD Weld with an Excessive Undercut, Refer to Illustration 11: Reweld the undercut with the TTD process adding filler wire, or weld with the original process.
Porosity and/or Other Discontinuities Visible in the TTD Weld: Porosity and any other visible defects must be removed and the weld repaired.Toe Grinding of Fillet Welds for Improved Fatigue Life
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(7) Carbide tipped burr, the preferred burr shapeNote: The profile or geometry of the weld toe controls the fatigue performance of fabricated structures. These fabricated structures have attachments that are fillet welded to highly stressed members. Fatigue performance improvement can be achieved through alteration of the original toe profile by several post weld treatment options. This procedure describes a method of using a mechanical means in order to remove adverse profiles and adverse stress risers. This method creates a smooth transition from one component to the next component.Equipment
Table 1
Required Equipment    
Tool    Description    
Hand Held Grinder     High speed, pneumatic, rotary, pencil grinder 20,000 rpm    
Compressed Air    
621 kPa (90 psi) minimum    
Tungsten Carbide Burr     The burr should be conical shaped with approximate end diameter of
10.0 mm (0.39 inch)    
Leather Welding Jacket        
Leather Gloves        
Safety Glasses        
Face Shield        
Radius Gauge        
Bridge Cam Gauge        
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(E) 45 degrees (F) 45 degrees (G) Minimum depth of 0.8 mm (0.03 inch) and a maximum depth of 1 mm (0.04 inch) (8) Burr tool (9) Direction of travel (10) Weld (11) PlateThe burr tip should be located over the weld toe. The axis of