PRODUCT SUPPORT PROGRAM FOR REPAIRING CRACKS IN THE MAIN FRAME ABOVE THE REAR AXLE MOUNT ON CERTAIN 416F, 420F, AND 430F BACKHOE LOADERS Caterpillar

PRODUCT SUPPORT PROGRAM FOR REPAIRING CRACKS IN THE MAIN FRAME ABOVE THE REAR AXLE MOUNT ON CERTAIN 416F, 420F, AND 430F BACKHOE LOADERS

Usage:

TEBE3478-01

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24Aug2015

(Revised 22Jun2017)

U-456

A-327

D-386

O-390

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After Failure Only	PRODUCT SUPPORT PROGRAM FOR REPAIRING CRACKS IN THE MAIN FRAME ABOVE THE REAR AXLE MOUNT ON CERTAIN 416F, 420F, AND 430F BACKHOE LOADERS
7000 7054		PS53021

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NOTE:	Caterpillar’s obligations under this Service Letter are subject to, and shall not apply in contravention of, the laws, rules, regulations, directives, ordinances, orders, or statutes of the United States, or of any other applicable jurisdiction, without recourse or liability with respect to Caterpillar.
NOTE:	This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS53021" as the Part Number and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.

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NOTE:

The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.

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NOTE:	This Revised Service Letter replaces 24Aug2015 Service Letter. Changes have been made to the Rework Procedure, Welding Procedure, Step 9. A note has been added.

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TERMINATION DATE

31Aug2017

PROBLEM

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The main frame can crack along the welds between the plates above the rear axle mount on certain 416F, 420F, and 430F Backhoe Loaders.

AFFECTED PRODUCT

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Model	Identification Number
416F	LWT00150-00785
416F ST	KSF00150-02254
420F	LKH00150-00151, 153-516 LTG00150-01210, 1215-2342
420F IT	JWJ00150-03288
420F ST	SKR00150-05380, 6996, 45157
430F	LDY00150-00281 LNH00150-00208
430F IT	RGS00150-00376, 378-762
430F ST	RDF00150-00332, 334-870

PARTS NEEDED

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No parts needed for this program

ACTION REQUIRED

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Refer to the locations shown in Images1 and 2. If cracks are found in any of welds in these locations, inspect both the inside and outside of the chassis, on the L/H and R/H side of the machine. The rear wheels may need to be removed in order to inspect the outside faces of the chassis.

NOTE: If the machine application is 100% hammer work then STOP, and contact the Backhoe Loader Product Support Team (David Council - Council_David_N@cat.com) for further instructions.

If cracks are found (greater than 2 inches/50mm long) and have spread from the welds and into the side plates as per Image3, then STOP, and contact the Backhoe Loader Product Support Team (David Council - Council_David_N@cat.com) for further instructions.

Smaller cracks (less than 2 inches/50mm long) can be repaired according to the attached Rework Procedure.

For machines that have a crack in any of the welds, refer to the attached Rework Procedure.

NOTE: Rework BOTH SIDES, INSIDE AND OUT, even if you did not find any cracks in other welds.

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Image1

Image2

Image3

SERVICE CLAIM ALLOWANCES

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Product smu/age whichever comes first	Caterpillar		Dealer Suggested		Customer Suggested
Product smu/age whichever comes first	Parts %	Labor Hrs%	Parts %	Labor Hrs%	Parts %	Labor Hrs%
0-3000 hrs, 0-36 mo	100.0%	100.0%	0.0%	0.0%	0.0%	0.0%
3001-6000 hrs, 37-60 mo	33.0%	50.0%	0.0%	0.0%	50.0%	50.0%

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NOTE: This is a 14.0-hour job

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PARTS DISPOSITION

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Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

Rework Procedure

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A. Place the machine on firm level ground in an area suitable for performing the Rework Procedure.

B. Turn off and remove the key from the battery isolator switch. This will help protect the machine electronics during the welding procedures.

C. Remove the rear wheels and axle. Refer to UENR2303, Disassembly and Assembly, "Rear Axle - Remove", for additional information.

D. To aid in gaining access to the welds, other items will need to be removed or moved out of the way. Refer to UENR2303, Disassembly and Assembly, "Rear Axle - Remove", which will help with supporting the machine and removal of most components.

Removal of the Rear Wheels:

1. Undo receiver dryer and accumulator bracket (A) and tie out of the way. Refer to Image1.1.1.

Image1.1.1

2. Disconnect rear drive shaft (B). Refer to Image1.2.1.

3. Disconnect hand brake cable (C). Refer to Image1.2.1.

4. Disconnect differential lock hose (D). Refer to Image1.2.1.

5. Disconnect brake hoses (E). Refer to Image1.2.1.

6. Remove the rear axle.

Image1.2.1

7. Remove the filter?implement valve tube (F). Refer to Image1.3.1.

8. Undo hydraulic oil filter (G) and tie out of the way. Refer to Image1.3.1.

Image1.3.1

9. Remove ride control valve-accumulator hose (H) (if option is fitted). Refer to Image1.4.1.

10. Undo all other ride control hoses, cap and tie the hoses out of the way (I). Refer to Image1.4.1.

11. Remove ride control valve (J). Refer to Image1.4.1.

12. Undo four loader valve hoses, cap and tie the hoses out of the way (K). Refer to Image1.4.1.

13. Undo two hydraulic hose coupler valve hoses (if option is fitted), cap and tie the hoses out of the way (L). Refer to Image1.4.1.

14. Undo the hydraulic hose coupler valve and tie out of the way (M). Refer to Image1.4.1.

Note: Image1.4.2 is reference for how the area should look once all the parts are removed and any items tied out of the way of the area to be welded.

Image1.4.1

Image1.4.2

Welding Procedure:

1. Clean the frame both inside and outside to ensure it is free of dirt, oil, grease, or any other debris.

2. Inspect the area carefully for any cracks that may have been missed on the original inspection.

Note: If there are small cracks that have penetrated into the side plates (less that 2 inches/50mm long), they should repaired BEFORE completing the rest of the Rework Procedure.

Note: If a crack in a side plate extends longer than 2 inches/50mm, then STOP and contact Caterpillar BHL Product Support. Refer to the Action Required for the contact details.

3. Locate the crack and fully grind it out. If possible, grind 10mm past the end of the visible crack.

4. Ensure that the crack has been fully removed by using a dye penetrant kit. If not, grind away more material and check again.

5. Fully reweld the groove that has been made, proud of the parent material.

6. Grind the weld back so it is flush with the parent metal.

Once any small cracks have been repaired in the side plates that have been repaired, then continue with the repair for the other welds.

NOTE: The repair MUST be carried out in the correct sequence. This is important to allow for cooling and prevent distortion of the frame.

7. Working under the machine, remove all of the weld between the side plate and bottom axle mounting plate of the frame on the L/H INSIDE using a 8mm diameter air arc carbon electrode at around 500 Amps.

8. Under the machine, remove all of the weld between the side plate and bottom axle mounting plate of the frame on the R/H INSIDE using a 8mm diameter air arc carbon electrode at around 500 Amps.

Refer to Image1.6.1 for location of these welds.

Image1.6.1

9. Using the air arc tool, prepare a 8mm bevel or J-groove in the L/H INNER side plate. The bevel, or J-groove should be cut into the plate according to the dimensions in Image1.7.1.

NOTE: This part of the repair is very important. If the bevel is not made deep enough, or missed completely, it may result in the repair not being fully effective with cracks forming from the root of the weld again in the near future.

10. Repeat the 8mm bevel groove in the R/H INNER side plate around the radius.

11. Ensure all slag and carbon deposits are removed from the area.

Image1.7.1

12. Fully weld the 8mm weld preparations you have just made on LH INSIDE frame rail using either:

a) MAG Welding - 1.2 diameter wire inclined-vertical, 22 Volts 130-140 Amps horizontal-vertical 28-30 Volts 260-280 Amps.

OR

b) Stick/Arc Weld - inclined-vertical 130-140 Amps, 3.2 mm diameter low hydrogen electrode, horizontal-vertical 250-280 Amps, 5.00mm diameter electrode.

13. Minimize any stop-starts to ensure weld strength.

14. Repeat this on the R/H INSIDE frame rail.

15. Ensure all slag and carbon deposits are removed from the area.

Image1.8.1

Follow this procedure to fully reweld the rails:

Note: It is critical that the sequence is followed to allow cooling and prevent distortion in the frame.

Refer to Image1.9.1 and 1.9.2 for the location of each pass. The welds should start at the outside edge of the rail, and end at the top/center of the rail. Avoid any weld stops until you are at the center of the frame.

1. Weld a 10mm fillet on LH INSIDE rail, first pass 1st and 2nd welds.

2. Weld a 10mm fillet on RH INSIDE rail, first pass 3rd and 4th welds.

3. Weld a 10mm fillet on LH INSIDE rail, second pass 5th and 6th welds.

4. Weld a 10mm fillet on RH INSIDE rail, second pass 7th and 8th welds.

Both sides of the frame on the INSIDE are now repaired.

Image1.9.1

Image1.9.2

Before starting any welding or cutting on the OUTSIDE of the frame, temporarily refit the rear axle to the machine:

1. Attach the axle to the frame using the INSIDE bolts only. Tighten the bolts to a specified torque of 460 N.m.

2. Install a G-clamp between the frame and the axle on the OUTSIDE. Refer to Image1.10.1.

Note: This is important so the frame is not distorted during the next welding procedure.

Note: The axle MUST be flat to the frame during and after this repair.

Image1.10.1

Note: The repair MUST be carried out in the correct sequence. This is important to allow for cooling and prevent distortion of the frame.

3. Working under the rear fenders, remove all of the weld between the side plate and bottom axle mounting plate of the frame on the L/H OUTSIDE using a 8mm diameter air arc carbon electrode at around 500 Amps.

4. On the opposite side of the machine, remove all of the weld between the side plate and bottom axle mounting plate of the frame on the R/H OUTSIDE using a 8mm diameter air arc carbon electrode at around 500 Amps.

Refer to Image1.11.1 for location of these welds.

Image1.11.1

5. Using the air arc tool, prepare a 8mm bevel, or J-groove in the L/H OUTER side plate. The bevel, or J-groove should be made according to the dimensions in Image1.12.1.

6. Repeat the 8mm bevel, or J-groove in the R/H OUTER side plate around the radius.

7. Ensure all slag and carbon deposits are removed from the area.

Image1.12.1

8. Fully weld the 8mm weld preparations you have just made on L/H OUTSIDE frame rail using either:

a) MAG Welding - 1.2 diameter wire, inclined-vertical, 22 Volts 130-140 Amps, horizontal-vertical 28-30 Volts, 260-280 Amps.

OR

b) Stick/Arc Weld - inclined-vertical 130-140 Amps, 3.2mm diameter low hydrogen electrode, horizontal-vertical 250-280 Amps, 5.00mm diameter electrode.

Minimize any stop-starts to ensure weld strength.

9. Repeat this on the R/H OUTSIDE frame rail.

10. Ensure all slag and carbon deposits are removed from the area.

Image1.13.1

Follow this procedure to fully reweld the OUTSIDE of the rails:

Note: It is critical that the sequence is followed to allow cooling and prevent distortion in the frame.

Refer to Image1.6.1 for the location of each pass.

The welds should start at the outside edge of the rail, and end at the top/center of the rail. Avoid any weld stops until you are at the center of the frame.

1. Weld a 10mm fillet on LH OUTSIDE rail, first pass 1st and 2nd welds.

2. Weld a 10mm fillet on RH OUTSIDE rail, first pass 3rd and 4th welds.

3. Weld a 10mm fillet on LH OUTSIDE rail, second pass 5th and 6th welds.

4. Weld a 10mm fillet on RH OUTSIDE rail, second pass 7th and 8th welds.

Both sides of the frame on the OUTSIDE are now repaired.

5. Remove the rear axle from the machine.

6. Ensure any burnt paint, weld slag, carbon deposits and any other oil/debris are removed before repainting the repair.

7. Repaint all repaired areas using an etch primer and high gloss Caterpillar Yellow paint.

Refer to Image1.15.1.

Install the rear axle, and reinstall the components that were removed at the start of the repair. Refer to UENR2303, Disassembly and Assembly, "Rear Axle - Install", for correct method and torque setting for the rear axle. Bleed the brakes after the hoses have been refitted.

Lower the machine to the ground and check for leaks and correct operation before returning the machine back to the customer.