- Caterpillar Products
- Machines with Grease Lubricated Track with Swage
- Machines with Greased Lubricated Track (GLT)
- Machines with Positive Pin Retention (PPR) Track
- Machines with Positive Pin Retention 2 (PPR2) Track
- Machines with Rotating Bushing Track
- Machines with Sealed Positive Pin Retention (PPR) Track
- Machines with Sealed Track
- Machines with Sleeve Bearing Track
- Machines with SystemOne Undercarriage
- Machines with non-PPR Sealed and Lubricated Track
- Machines with Greased Lubricated Track (GLT)
- Track Drills
- MD5150C (S/N: SEY1-UP)
Introduction
Revision | Summary of Changes in SEBF8507 |
18–21 | Added serial number prefixes for New Product Introduction. |
17 | Added serial number prefixes for New Product Introduction.
Updated introduction information. |
16 | Added serial number prefixes for New Product Introduction. |
© 2019 Caterpillar All Rights Reserved. This guideline is for the use of Caterpillar dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.
This Undercarriage Reconditioning Bulletin contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Undercarriage Reconditioning Bulletin must be used with the latest technical information that is available from Caterpillar.
For technical questions when using this document, work with your Dealer technical Communicator (TC).
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Summary
This bulletin covers water-cooled welding of track rollers. Track roller preparation, welding steps, and bearing inspection are also covered.
Safety
Illustration 1 | g02139237 |
Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.
This bulletin may contain hazardous steps. A safety alert symbol like the one below is used to indicate a hazard.
Warning messages identify a specific, imminent, latent, hazard that has a reasonable probability of resulting in personal injury or death if the warning is ignored.
Illustration 2 | g03186216 |
Example warning |
Do not attempt to disassemble or assemble this machine until you read and understand the disassembly and assembly instructions. Improper disassembly and assembly procedures could result in injury or death. |
Inspect all threaded components before use. Damaged threads may fail under hydraulic pressure. Broken threads may release flying objects that are propelled with great force. Personal injury or death can occur if struck by flying objects. |
Do not stand near the hydraulic press while the press is in operation. A component that slips or breaks under pressure may fly into the air with great force. Personal injury or death can occur if struck by flying objects. |
Canceled Part Numbers and Replaced Part Numbers
This document may not include all canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.
Track Roller Preparation
The following recommendations apply to track roller preparation:
NOTICE |
---|
Do not weld (or rebuild) track rollers that have less than 70% tread wear. Do not weld track rollers that have more than 110% tread wear. If either roller tread surface is outside this range, the roller should not be rebuilt. |
Reference: Refer toSpecial Instruction, PEKP9400, "Custom Track Service Handbook" for measurement instructions and wear specifications.
- Remove the rollers from the machine.
- Clean the track rollers with high-pressure water or steam to remove large pieces of mud and packed in dirt.
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Illustration 3 g02441316 Use an air powered wire brush for further cleaning. - After the pressure washing, clean the roller tread surface and flanges using an air powered wire brush. Refer to Illustration 3. Rust and moisture must be removed from the roller surface. Surface contaminants, such as rust and moisture can cause hydrogen embrittlement and possible fracture of the track roller during weld buildup. Cleaning will contribute to the quality of the welding, since less dirt and oil get into the flux.
Note: During cold weather, the rollers must be at room temperature before welding is started. The recommended temperature range is
16° to 21° C (60° to 70° F) . - Visually inspect the flange and tread area of track rollers and bolt holes for evidence of crackling. If cracks are suspected but cannot be easily seen, use a magnetic particle or dye penetrant inspection technique. If cracks are found, do not weld the rollers.
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Illustration 4 g02441338 - Remove any metal rolled-over at the inner edge of the treads before welding any single flange roller. Refer to Illustration 4.
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Illustration 5 g02441356 - Elevated sprocket tractors have deeper wear limits on the track rollers. This deeper wear pattern must be trimmed. Trim the rolled-over material further back from the edge and downward toward the roller hub. Refer to Illustration 5.
Note: Trimming is necessary to prevent cracks from lengthening into the weld deposit.
Show/hide tableNOTICE When trimming the rolled-over material using a cutting torch, trim smoothly and uniformly to prevent notching. Notches can be a source of roller cracking.
- Use a grinder to smooth the rough areas after trimming.
Preparation of Track Rollers -Low Sprocket Tractors
- Remove the roller shaft oil plug and the end collars, then inspect the Duo-Cone seals. Refer to Illustration 6. Refer to Undercarriage Reconditioning Bulletin, SEBF8511, "Reusability Recommendations for Duo-Cone Seals" for inspection instructions.
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NOTICE Duo-Cone seals must be kept in matched pairs.
- Loose dirt should be removed from the end collars, but hard packed dirt should not be disturbed.
- Check bearing-to-shaft clearance with the
0.64 mm (0.025 inch) wire of the FT1412 gauge. Acceptable clearance ranges from1.26 mm (0.050 inch) down to0.64 mm (0.025 inch) . This clearance is needed to prevent shaft seizure after welding. - The
0.64 mm (0.025 inch) wire should be inserted into the area between the shaft and bearing, at the top, to a depth of50.8 mm (2.00 inch) to check the minimum clearance the entire length of the bushing.- If clearance is less than
0.64 mm (0.025 inch) , disassemble the roller and resize the bushing. - If the
1.26 mm (0.050 inch) wire can be inserted between the shaft and the bearing indicating that the clearance is more than 1.26 mm, replace the bushing.Note: Try to have resized exchange bushings available to speed up the rebuilding process. Usually re-sizing is required only at the time of the first rebuild. Subsequent rebuild clearance is generallygreater than the minimum clearance.
Show/hide tableIllustration 7 g02441361 - If clearance is less than
- Inspect the roller components to prepare for assembly. Check the end collars for cracks. If the roller shaft was removed, make sure that the roller shaft is clean and oil passages are free of dirt and obstructions. The bushings should be clean and dry. Lubricate the bushing bore, O-ring seal, and thrust face before assembly. See Illustration 7.
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Illustration 8 g02441376 - Install the Duo-Cone seals after the shaft and bushings have been assembled. Correct Duo-Cone seal installation is critical for the long life of a roller. See Bulletin MP7, SEBF8511-01 for detailed instructions. Lubricating the toric ring may cause leakage during welding. The end collars should be wired or banded to prevent internal pressure from forcing the end collars away from the shaft on roller groups. See Illustration 8.
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Illustration 9 g02441378 External water probe. Check the probe seal and shaft prior to each use. - Set up the water supply. If the welding machine uses an external water probe, check the probe seal and shaft prior to each use. See Illustration 9. A damaged water seal or loose shaft can restrict water circulation inside the roller. The resulting heat buildup can damage internal roller components. Install the water probe, water hoses and turn on the water. If a leak develops, rotate the shaft inside the roller to seat the seals. A continuous leak is usually from damaged or omitted seals, or Duo-Cone seals that are defective. The leak check should be made before the roller is placed in the welder to prevent water from leaking into the flux supply.
Illustration 6 | g02441359 |
Preparation of Track Rollers -Elevated Sprocket Tractors
Elevated Sprocket machine track rollers must be disassembled and a cooling adapter installed to permit water-cooled welding. Resizing of the track roller bushings is done after the rollers are welded.
- Remove hardened dirt and debris from around the roller retainer bolt heads. The use of a pneumatic scribing tool quickly and safely removes this dirt and debris using high vibration and air pressure. See Illustration 10.
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Illustration 11 g02441383 Remove the retainers from the rollers Show/hide tableIllustration 12 g02441397 Remove the duo-Cone seal (inner) from the rollers Show/hide tableIllustration 13 g02441398 Remove the roller shaft from the rollers - Remove the track roller retainers, the Duo-Cone seal (inner), and the roller shaft from the rollers. See Illustrations 1011,12, and 13.
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Table 2 Model D11T
D11R
D11N
D10T
D10R
D10N
D10
D9LD9T
D9N
D9R
D8T
D8N
D8R
D8L
D8
D7R
D7H
D7E
D7973
963
953
943
D6T
D6R
D6N
D6M
D6H
D6K
D6
D5N
D5M
D5H
D4H
D4Cooling Adapter 6V-6140 6V-6163 1U-5530 End Plate 6V-7048 6V-7049 6V-7053 1U-5532 1U-5531 End Plate Seals 8F-8733 8F-9516 5F-3106 2J-8163 5H-6734 Bearing Housing Assembly 6V-7055 6V-7054 1U-5533 Adapter Shaft Assembly 6V-7056 6V-7056 1U-5534 Quick Disconnect Couplings 1 5V-8610 5V-8611 5V-8610 5V-8611 5V-8610 5V-8611 Thrust Washers 9N-1545 9N-1545 9J-0114 Shaft Seal 2H-3933 2H-3933 3H-2652 Retainer Ring 9H-5604 9H-5604 7H-4574 Adapter Seals 8F-8733 8F-9516 5F-3106 2J-8163 5H-6734 1The quick disconnect coupling must be used for the cooling adapters.
Note: There are three cooling adapters used during welding. The components are given in table 2.
Show/hide tableIllustration 14 g02441419 - The quick disconnect couplings shown in Illustration 14 are not a part of the cooling adapter and must be ordered separately. The Caterpillar part numbers for the quick disconnect couplings are 5V-8610 and 5V-8611. It is recommended that these larger couplings be used to replace the smaller fittings in all the water and air lines of the welding machines and other water probes or adapters.
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Illustration 15 g02441418 - To assemble the cooling adapter, select the correct side of the housing for the side of roller to be welded. See Illustration 15.
- Assemble a thrust washer and the shaft O-ring seal to the adapter shaft. See Illustration 14. Lubricate the shaft and bearing with a multipurpose grease. Using a twisting motion, press the shaft into the bearing housing.
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Illustration 16 g02441437 - Install the second thrust washer, retainer springs, and the O-ring seal in the flange of the bearing housing as shown in Illustration 16. Check the water inlet tube and water return hole. A loose tube or a restriction in the tube or return hole can result in an overheated roller. Connect the quick disconnect coupling so the incoming water is directed to the water inlet tube.
Note: Adapters should be disassembled, cleaned, and lubricated periodically.
Show/hide tableIllustration 17 g02441438 - Fasten the end plate to the roller using three bolts. See Illustration 17. The retainer faces of the track roller must be clean to ensure a good O-ring seal on both sides of the roller.
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Illustration 18 g02441439 - Fasten the adapter to the opposite side of the roller with three bolts. See Illustration 18. (Adapter is pictured with couplings).
- Prior to placing the roller in the welder, assemble the water connections and check for leaks. The most probable cause of leaks would be a damaged or omitted O-ring seal.
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Illustration 19 g02441440 - Place the roller in the welder and make sure that the holding devices are secure and in correct alignment. Recheck the roller for water leaks. Do not drive the roller with a block tack-welded to the flange. Doing so could result in a stress riser which could cause cracking. The adapters are driven by the
FT-1738 Stud. See Illustration 19.
Illustration 10 | g02441379 |
CP9361 Air Scribe Tool |
Flange Welding Procedure
Total rebuild (welding) of flange and treads may be cost prohibitive and can result in future cracking.
Do not rebuild any track roller flanges unless necessary. Consider cost and refer to the following criteria to determine if flange welding should be done.
NOTICE |
---|
It is important that flange welding occurs before roller tread welding. |
- Preheat the flange to a temperature of
204° C (400° F) . The preheating will dissipate any grease, water, or oil on the flanges.Note: Heat will be distributed evenly into the tread and roller when welding flanges first. Welding flanges first normalizes thermal stress.
Show/hide tableIllustration 20 g02441458 - Refer to illustration 20 and table 3 for minimum rebuild criteria.
Note: Refer to "Flange Welding Parameters" for welding equipment.
Show/hide tableTable 3 Flange Welding Measurements To Weld a Roller Flange On: X Must Be Less than: D11N
D11R
D11T20.7 mm (0.81 inch) D10N
D10R
D10T14.7 mm (0.58 inch) D10 22.24 mm (0.876 inch) D9N
D9R
D9T13.0 mm (0.51 inch) D9L 13.7 mm (0.54 inch) D9 14.22 mm (0.560 inch) D8N
D8R
D8T13.0 mm (0.51 inch) D8L 11.01 mm (0.433 inch) D8 12.7 mm (0.50 inch) D7E
D7H
D7R13.0 mm (0.51 inch) D7 9.7 mm (0.38 inch) D6
D6K
D6H
D6M
D6N
D6R
D6T10.0 mm (0.39 inch) D5
D5H
D5M
D5N9.0 mm (0.35 inch) D4
D4H8.0 mm (0.31 inch) Show/hide tableIllustration 21 g02441476 Welding is to be initiated at the radius between the tread and flange. - Welding should be initiated in the radius between the tread and flange using a stringer bead. Refer to Illustration 21.
- After flange welding is complete, be prepared to continue with tread welding. Go to the section titled "Tread Welding Procedure".
Flange Welding Parameters
Use the following welding parameters for rebuilding track roller flanges:
Wire Type | |||
Parameters | Stoody 205 HD | Stoody 105, 105B | Lincore 40 |
Flux | Stoody Rollrite HD | Stoody Rollrite | Lincoln 880 |
Amps | 400 | 350 | 350 |
Volts | 30 | 26 | 26 |
Wire Speed Feed | 95 ipm | 43 ipm | 62 ipm |
Stickout | |
|
|
Polarity | Reverse | Reverse | Reverse |
Rotation | 30-35 ipm | 30-35 ipm | 30-35 ipm |
Note: To avoid weld failures, use only the recommended combinations of submerged arc weld fluxes and wires.
Illustration 22 | g02441496 |
Wire feed speed is related to amperage and is a more precise means of controlling weld deposition rates. The Lincoln Electric portable wire feed speed meter, Model No. K283, can be used to measure the speed of the wire being pulled by the drive motors. See Illustration 22.
Lincoln Electric portable wire feed speed meter, Model No. K283
Wire feed speed measurement is required for machine setup.
Tread Welding Procedure
- Check the general condition of the roller welding machine and make sure that all functions are in good working order.
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Illustration 23 g02441498 - Replace any worn welding tips. A welding tip is considered unusable when the hole is worn to an oval shape 50% larger in width than the diameter of the welding wire. Worn welding tips will allow the wire to whip during weld buildup, causing poor weld appearance. See Illustration 23.
- Use the proper wire and flux combination to assure a good weld appearance. Small pieces of slag should be filtered out of the flux used for submerged arc welding. New flux should be blended with old flux to provide a proper flux which can be used with hardfacing wire to obtain a desired hardness and chemistry. Do not use more than 25% recycled flux. Do not use reground flux as reground flux contributes to cracking. It is more cost efficient to use new flux than to replace a cracked roller.
Note: When using Stoody 205 HD wire, Rollrite HD flux, the slag produced cannot be reground. The economics of regrinding and flux properties do not warrant reuse.
- Prepare the roller for welding.
- Flange welded: If flange welding is performed, weld the roller treads immediately after the flanges. Rollers should be at
204° C (400.0° F) - Flange not welded: Rollers should be preheated to a temperature of approximately
204° C (400.0° F) . Preheating will remove any condensation and surface contaminants and reduce thermal shock to the roller. Preheating will take 3 to 5 minutes to heat a cool roller to this temperature. Leave off the water pump during this time to allow the roller to warmup faster and retain the heat.
- Flange welded: If flange welding is performed, weld the roller treads immediately after the flanges. Rollers should be at
- Use a fire-resistant material to retain the flux on the roller tread. Welding a stringer bead on the inside edge of single flange rollers is not recommended since this can result in roller cracking.
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Illustration 24 g02441499 Weld head in correct position above roller - Place the welding head about
6.4 mm (0.25 inch) ahead of top dead center. Adjust the lead as necessary to obtain the proper bead, but never put the welding head behind top dead center. See Illustration 24.Show/hide tableIllustration 25 g02441519 - Position the tip of the welding torch approximately
31.75 mm (1.250 inch) above the roller tread. See Illustration 25. The current being conducted through the exposed wire will preheat the wire and permit an increase in deposition from electrical stickout. Raise the tip as needed to maintain this distance from the roller tread. Once the arc is initiated, be sure to turn the water pump back on. - Apply a
25.4 mm (1.00 inch) wide oscillating pass in the center of treads using an oscillating speed of 75-80 inches per minute with .200 in. index. Oscillating speed is set by oscillating the welding tip in 1 inch strokes per minute. Index is set by roller rotation in inches per oscillation. These settings should be made prior to starting the welding. - When the weld is initiated, adjust the electrical controls for proper weld parameters.
Adjust the electrical controls for weld parameters. Refer to table 5.
Show/hide tableTable 5 Stoody 205 HD 103 ipm wire feed speed
450 amps (30 V)Stoody 105 or 105B 52 ipm wire feed speed
375 amps (28 V)Lincore 40 107 ipm wire feed speed
475 amps (28 V) - When the roller has rotated to the starting point of the weld, increase the width of the pass. Reduce the oscillating speed to 50-55 inches per minute.
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Illustration 26 g02441520 Note: The tread surface of most rollers will be worn concave. See Illustration 26.
- Use partial width welding passages to fill in the lower areas of the tread surface to level it. This permits the weld material to feather into the parent material. Do not use dwell (hesitation) during this fill-in process, even if the tread is worn flat. Begin with at least one narrow weld pass to warmup the roller.
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Illustration 27 g02441521 Show/hide tableIllustration 28 g02441522 - Build the tread surface up to a finished diameter. Use dwell to get good tie-in of the tread surface to the flanges. Dwell provides a radius between the tread and flange to reduce the chances of inclusions and stress risers. See Illustration 27 and Illustration 28.
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NOTICE Do not weld any stringer beads on the tread surface. This is the main cause of cracking hard core rollers welded by the water-cooled process.
- Once the tread welding has started, do not stop until the tread is built up to the finished diameter. The Handbook, PEKP9400, "Custom Track Service" provides roller tread diameters for reference of buildup.
NOTICE |
---|
It is important that flange welding be done before roller tread welding. |
Tread Welding Parameters
The following welding parameters are recommended for rebuilding track rollers.
Consumables | ||||
Type of Wire | ||||
Parameters | Stoody 205 HD | Stoody105
Stoody 105B |
Lincore 40 | Welding Alloys P-S |
Flux | Stoody Rollrite HD | Stoody Rollrite | Lincoln 880 | Stoody Rollrite |
Wire Feed Rate | 103/95 ipm1 | 52 ipm | 107/70 ipm1 | 100/73 ipm1 |
Amperage | 450/4001 | 375 | 475/3751 | 450/4001 |
Volts | 30 | 28 | 28 | 28 |
Polarity | Reverse | Reverse | Reverse | Reverse |
Deposition Rate | 16.1 lb/hr
15.3 lb/hr1 |
9.5 lb/hr | 14.0 lb/hr
10.4 lb/hr |
16.1 lb/hr
15.3 lb/hr1 |
Deposition Efficiency | .94 | .9 | .87 | .92 |
Flux to Wire Ratio | .6 lb | 1.12 lb | .80 lb | .65 lb |
1Smaller Rollers (D7 and smaller) must be rebuilt at reduced welding parameters to avoid problems with weld pool control and slag removal.
Note: To avoid weld failures, use only the recommended combinations of submerged arc weld fluxes and wires.
The following Consumable Arc Time Comparison Track Rollers Chart can be used to compare welding times. The four columns show the welding times for rebuilding a 100% worn roller using the products and the recommended welding parameters listed in Illustration 6. No flange welding was included in the times.
Consumable Hour Ranges | |||
Roller Size & Part No. | Stoody 105 or 105B | Lincore 40 | Stoody205 HD |
D11N
D11R D11T |
4.03 to 4.73 | 2.73 to 3.21 | 2.52 to 2.97 |
D10N
D10R D10T |
3.42 to 4.00 | 2.32 to 2.71 | 2.15 to 2.51 |
D10 | 2.25 to 3.33 | 1.53 to 2.26 | 1.41 to 2.09 |
D9N
D9R D9T |
2.93 to 3.55 | 1.99 to 2.41 | 1.84 to 2.23 |
D9L | 2.13 to 2.82 | 1.45 to 1.91 | 1.34 to 1.77 |
D9 | 1.36 | 0.92 | 0.84 |
D8N
D8R D8T |
2.12 to 2.46 | 1.44 to 1.67 | 1.33 to 1.55 |
D8L | 1.59 to 2.21 | 1.08 to 1.50 | 1.00 to 1.39 |
D8 | 1.09 | 0.74 | 0.68 |
983 | 1.07 | 0.73 | 0.67 |
D7E
D7H D7R |
1.01 | 0.92 | 0.66 |
D7 | 0.67 | 0.62 | 0.44 |
D6
D6K D6H D6M D6N D6R D6T |
0.57 to 0.88 | 0.52 to 0.81 | 0.38 to 0.58 |
D5
D5H D5M D5N |
0.42 to 0.66 | 0.39 to 0.61 | 0.28 to 0.44 |
D4
D4H |
0.30 to 0.42 | 0.28 to 0.38 | 0.20 to 0.28 |
973 | 0.68 to 1.14 | 0.62 to 1.04 | 0.45 to 0.75 |
963 | 0.56 to 0.96 | 0.51 to 0.88 | 0.37 to 0.63 |
953 | 0.44 to 0.75 | 0.40 to 0.69 | 0.29 to .050 |
943 | 0.33 to 0.52 | 0.30 to 0.48 | 0.22 to 0.34 |
The two most important factors which influence bead development when welding in the oscillating mode is lead and oscillating speed. Lead is the distance ahead of the roller centerline at which the weld deposit is made. Oscillating speed determines bead size. The faster the speed, the narrower the bead. Extra factors which influence bead contour are arc voltage, amperage, and spindle index. Voltage determines the width and shape of the bead. Amperage (wire feed speed) determines the rate of deposition and penetration. The spindle index determines the thickness of the weld deposit.
See Illustration 29 and table 8 for various kinds of beads that can be produced by the oscillating technique. By observing the bead patterns and making the adjustments indicated, the various improper bead forms can be corrected.
Illustration 29 | g02441556 |
Bead | Cause/Result | Remedy | |
Bead A
(Puddle Effect) |
Incorrect | The lead is either too far behind the roller centerline (top dead center) or the oscillating speed is too low. | Correct the lead and/or the oscillating speed. |
Bead B
(Lazy Eight) |
Incorrect | The gap between the beads is caused by the spindle index being too high. The gap between the beads indicates little or no dwell. The stretched eight-shaped pattern indicates that the oscillation speed is too high. | Correct the spindle index and/or dwell amount. Also consider working with oscillation speed. |
Bead C
(Little Dwell) |
Incorrect | Too little or no dwell on the flange side and too much metal running over the inner edge. | The use of fire-resistant material to form a flux dam is especially important for the inside edge of single flange rollers. |
Bead D
(No Dwell) |
Incorrect | Dwell-less bead with too much index. | The index should be reduced so beads will overlap better. |
Bead E
(Wrong Lead) |
Incorrect | Distortion caused by improper lead plus excessive dwell on the outside flange. | By reducing the left hand dwell, the excess buildup can be eliminated. Properly adjusting the lead will eliminate the wave like effect found in the rest of the bead. |
Bead F represents a correctly oscillated welding bead. |
Post Welding Procedure
Slow cooling will allow stresses to normalize and allow any entrapped hydrogen to diffuse to the surface through the weld material.
Use the following information to make sure that the track rollers are rebuilt with maximum quality.
- After water circulation is discontinued, use high-pressure air to force the waste water through the water adapter.
- Allow rollers to cool.
Note: To prevent rapid cooling in colder climates, the welded rollers can be placed in an insulated box or a container filled with the used submerged arc welding flux.
Note: The rollers can also be covered with a fire retardant blanket right after welding to slow down the cooling process.
Show/hide tableNOTICE Allow the roller to cool slowly. Do not set roller on a concrete floor or near a draft of air.
- Lubricate and store rollers:
- Low Sprocket Tractor Rollers: After cooling to room temperature, these rollers should be filled with lubricating oil and dipped in a protective coating until ready for use.
- Elevated Sprocket Rollers: If roller bushing-to-shaft clearance is within specifications, reassemble rollers, fill with lubricating oil, and dip in protective coating.
Note: The wire on the end collars should be left on during storage to prevent end collar separation during handling.
Note: To prevent possible cracking of welded rollers during cold weather, store rebuilt rollers in a heated storage area.
Welding Highlights
- Both track roller treads must be worn between 70 and 110%. The track roller flanges must meet the dimensions given in this bulletin.
- Rollers should be at a minimum temperature of
16° C (60.8° F) before starting to preheat for welding. - Clean all the weld surfaces including the flanges. Use a wire brush or an 8T-3054 Metal Reconditioning Disc and an air powered tool to clean the flanges.
- Remove the cold-flow rolled material from the single flange rollers. Make a smooth and even cut at a 45º angle. Trim behind any fractured areas and trim down toward the roller hub. Check for cracks in the trimmed areas, around the bolt holes and in the existing weld surfaces. Dress the cut with a grinder to remove all rough areas and all excess slag and carbon. Be careful not to notch the roller with the grinder.
- Do not tack weld anything on the roller.
- Install the proper water adapter on the roller, and mount both the roller and the water adapter on the welding machine.
- If the flanges are to be welded, preheat the flanges to
204° C (400° F) . Weld the flanges before welding the treads. Start the arc in the radius between the flange and the tread. - Preheat the treads
204° C (400° F) to remove moisture and other contaminants and to warm the surface area of the roller. - Use the proper combination of welding wire and flux. Use clean flux. Filter the flux to remove slag, and do not use more than 25% recycled flux.
- Weld with the wire at positive polarity (reverse).
- Check the machine parameters for the correct wire feed speed amperage, voltage, oscillation speed, and indexing.
- Do not use stringer beads on the treads.
- The first weld pass should be approximately
25.4 mm (1.00 inch) wide and at 75 ipm to 80 ipm oscillating speed. - All weld layers should meet the flange with a smooth radius
- Do not stop welding until the roller is rebuilt.
- Allow the roller to cool slowly. Do not set roller on the concrete floor or where there is a draft.
- Rebuild the roller to the 0% wear limit. Do not weld the roller oversize.
Roller Bushing Resizing
Track roller bushings on Low Sprocket Tractors must be resized if the bushing-to-shaft clearance before welding is less than
On track rollers of Elevated Sprocket Tractors bushing-to-shaft clearance are checked after the rollers are welded with the cooling adapters. Install the roller shaft and insert a
A bearing burnishing procedure has been developed which increases the bushing diameter to correct the distortion created during welding. This procedure and tooling are presented in Bulletin, SEBF8586, "Removal, Installation, and Conditioning of Idler Bearings and Track Roller Bearings".