Usage:
D250E (5TN),
D300E (7FN) Articulated Trucks
Description of Change: The cover assembly on the transmission has been improved to prevent contact with the rear chassis.
Adaptable To: The new 148-5094 Transmission Cover Assembly is a direct replacement for the former 122-8858 Transmission Cover Assembly and is effective with D250E (5TN1592, 1603, 1604, 1605, 1607, 1608, 1614-1622, 1624, 1625, 1626, and 1629-up) and D300E (7FN908-up) Articulated Trucks. Previous machines can be adapted by replacing the cover assembly or by making the following modifications to the former 122-8858 Transmission Cover Assembly.
1. Cut the 122-8858 Transmission Cover Assembly to the dimensions shown in Illustration 1.
2. Produce two plates made from 2.0 mm (.08 in) thick ASTM A36 steel to dimensions shown in Illustration 2. The plates must be flat within 3 mm (0.1 in).
3. Read the following weld procedure. Weld the plates to the 122-8858 Transmission Cover Assembly on both sides with a 3 mm (0.1 in) fillet weld all around and install.
Illustration 1. 122-8858 Transmission Cover Assembly. Dimensions in chart. Cut away hatched area marked in Detail A on both sides. Weld new plates in position shown in Detail A on both sides.
Illustration 2. Quantity of two plates to be produced. Dimensions in chart. Use 2 mm (.08 in) ASTM A36 steel.
NOTE: Refer to Service Magazine, October 6, 1997, page 44, "Proper Welding Procedure On Machines And Engines With Electronic Controls".
Weld Information
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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 kill.
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Read and understand the manufacturer's instructions and your employer's safety practices. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and general area. Wear correct eye, ear, and body protection. Do not touch live electrical parts.
See American National Standard Z49.1 "Safety in Welding and Cutting" published by the American Welding Society, 2501 N.W. 7th Street, Miami, Florida 33125: OSHA Safety and Health Standards, 29 CRF 1910, available from U.S. Dept. of Labor, Washington, D.C. 20408.
NOTE: Welding operator personal protection should be provided to assure that total weld fume in the operators breathing zone does not exceed OSHA limits.
All repair welding operators must be qualified for groove and fillet welding, as outlined the current ANSI/AWS D14.3. The qualification will be for the SMAW (Shielded Metal Arc Welding) process in the vertical welding positions. The welding operator must also have used this welding process during the last six months or be re-certified for this process before welding. Documentation must be maintained of the weld operators qualifications. The alternate process for this repair could be FCAW (Flux Cored Arc Welding).
The area to be welded and the surrounding area must be at a minimum temperature of 16° C (60° F) before and during welding.
NOTE: Since weld distortion is a possibility, minimizing the heat is important.
The SMAW process shall be used with E7018 (ANSI/AWS A5.5) welding electrode in open enviroN·ments. The GMAW or the FCAW (Flux Cored Arc Welding) should be used in enclosed enviroN·ments. The weld deposited by these electrodes will have the following minimum mechanical properties:
- 500 MPa (72 KSI) Tensile Strength
- 420 MPa (60 KSI) Yield Strength
- 22% elongation in 50 mm (2 in)
- 27 J (20 ft lb) Notch Toughness at -29° C (-20° F)
- 420 MPa (60 KSI) Yield Strength
These are low hydrogen electrodes and must be stored in an electrode oven at 120° C (250° F) when not in use. If the electrodes get damp, scrap or recondition them to the manufacturer's specifications.
Where possible, welds should be made in the flat or horizontal position.
The following chart relates to the electrodes diameter and approximate current settings for welding:
Use the direct current electrode positive (DC reverse polarity) polarity setting and remove the slag after every pass. The weld pass size shall not exceed two times the electrode diameter.
Welding parameters will vary due to weld position and manufacturer of the welding electrode. For 1.30 mm (.052 in) diameter electrode typical welding parameters should be:
Clean the metal of oil, grease, paint, and dirt in the area to be welded. Attach the welding ground cable directly to the area to be welded. Protect all machined surfaces from sparks or splatter produced by the welding, chipping, and/or grinding operations.
The welds shall be free from cracks, porosity, undercut, and incomplete fusion. All weld quality shall conform to ANSI/AWS D14.3.