Rework Kit Available To Stiffen Main Frame Caterpillar

Rework Kit Available To Stiffen Main Frame

Usage:

TELEHANDLERSTH62 (3LN1-UP, 4TM1-UP) TELEHANDLERS

Problem:

Rework Kit Available to Stiffen Main Frame Problem: Cracks have been reported in the main frame of some TH62 machines operating under arduous conditions. The problem area can be located forward of the compensating cylinder anchor mounts, as indicated in illustration 1.

Solution:

Repair existing cracks and add plates to the inner and outer sections of the main frame. Add extra material (approx 400 mm) to increase the overall length of the top plate. Kit part number 156-4518 is available and can be installed to all TH62 machines in service. The kit comprises the parts listed in chart 1.

To gain access to the affected area it will be necessary to remove the engine hood, the engine hood backplate and the engine muffler and exhaust pipe as far as the exhaust manifold.

If a Longitudinal Stability Indicator system is installed, then the strain sensor must be removed from the main frame mounting pads. The LSI system will need recalibrating when the strain sensor is reassembled back onto the main frame. (Full details of strain sensor installation and calibration procedure is covered in SENR5861-02 System Operation,Testing and Adjusting, Longitudinal Stability Indicator System).

Procedure

Use a low hydrogen process for welding and an ambient temperature of approximately 70 degrees fahrenheit.

Refer to illustration 1.

1. Remove 120mm from the front of top plates as indicated. Grind off weld runouts at ends of top plates. Grind smooth to clean area of plate removal.

Refer to illustration 2.

2. Repair all cracks in main frame by:

a) Using Magnaflux or similar technique, locate and determine full extent of crack. Grind out crack to a single "V" (be sure end of crack is removed).

b) If required insert a 3mm backup strip (tack wires to hold in place). Fully weld "V" and grind surface smooth in fore/aft direction.

Refer to illustration 3.

3. Position 156-5660 Plates (4 off) centered on cracks as shown. Weld 8mm continuous fillet all round.

Refer to illustrations 4 and 5.

4. Position 156-5659 Plate-LH and 156-8455 PLate-RH as shown. Weld 8mm continuous fillet each side of main frame sideplates as indicated.

Additional Welding Information:

Manual Metalic Arc Welding.

Low Hydrogen Electrodes.

BS639: 1976 E5153 B12 (H) - COSA

AWS A5. 1 E7018 - NACD

1/4" Dia Rod Part No. 1U-5236

7/32" Dia Rod Part No. 1U-5235