New Holland Undercarriage and Components Technical Manual

TECHNICAL MANUAL UNDERCARRIAGE AND COMPONENTS

Issued 08-2005 6-80040 NA

CONSTRUCTION

CONSTRUCTION

TECHNICAL MANUAL

UNDERCARRIAGE AND COMPONENTS

BD04B073B

Bur • Issued 08-2005 Printed in U.S.A. • Book/Form Number 6-80040 NA Copyright © 2005. CNH America, LLC. All Rights Reserved.

CNH America LLC reserves the right to make improvements in design or changes in specifications at any time without incurring any obligation to install them on units previously sold.

All data given in this publication is subject to production variations. Dimensions and weights are only approximate. Illustrations do not necessarily show products in standard condition. For exact information about any particular product, please consult your Dealer.

Revision History Issue

Issue Date

Applicable Machines

Remarks

First Edition

6-80040 NA

All

6-80040 NA

Any use of editorial or pictorial content is strictly prohibited without express written permission from CNH America LLC. Carol Stream, IL 60188 U.S.A..

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TABLE OF CONTENTS CRAWLER UNDERCARRIAGE COMPONENTS ............................................................................................................ 1-1 UNDERCARRIAGE WEAR AND MEASUREMENT ........................................................................................................ 1-2 Track Measuring Tool Kit ....................................................................................................................................... 1-2 Record Keeping .................................................................................................................................................... 1-2 Before Measuring .................................................................................................................................................. 1-3 Rebuilding ........................................................................................................................................................... 1-3 Repositioning ....................................................................................................................................................... 1-3 Track Simulator .................................................................................................................................................... 1-3 UNDERCARRIAGE COMPONENTS ............................................................................................................................ 1-4 UNDERSTANDING UNDERCARRIAGE WEAR ............................................................................................................. 1-5 Wear You Can Not Control ..................................................................................................................................... 1-5 Wear You Can Partially Control ............................................................................................................................... 1-5 Wear You Can Control ........................................................................................................................................... 1-7 EXTENDING UNDERCARRIAGE LIFE ......................................................................................................................... 1-8 Track Adjustment and Inspection ............................................................................................................................. 1-8 SPROCKET WEAR AND MEASUREMENT ................................................................................................................... 1-9 Clean Track ......................................................................................................................................................... 1-9 Sprocket Wear Patterns ........................................................................................................................................ 1-10 Measuring Sprocket Wear ..................................................................................................................................... 1-15 BUSHING WEAR ..................................................................................................................................................... 1-16 Bushing Off-Center Wear ...................................................................................................................................... 1-16 Roller Flange Wear on the Bushing ......................................................................................................................... 1-16 Bushing Vertical Wear .......................................................................................................................................... 1-16 Bushing Reverse Drive Side Wear .......................................................................................................................... 1-16 Bushing Forward Wear ......................................................................................................................................... 1-16 Bushing Cracks (Non-Lubricated Track) ................................................................................................................... 1-17 Bushing Cracks (Lubricated Track) ......................................................................................................................... 1-17 Pins and Bushings (Pitch Extension) ....................................................................................................................... 1-17 TRACK PIN WEAR .................................................................................................................................................. 1-18 Pin Surface Wear ................................................................................................................................................. 1-18 Pin Spalling ......................................................................................................................................................... 1-18 Pins Breaking ...................................................................................................................................................... 1-18 Pin End Wear ...................................................................................................................................................... 1-18 TRACK LINK WEAR ................................................................................................................................................ 1-19 Link Uneven Top Wear ......................................................................................................................................... 1-19 Side Wear of the Link Rail ..................................................................................................................................... 1-19 Wear on the Inside Surface of the Link .................................................................................................................... 1-19 Pin Boss Top Wear .............................................................................................................................................. 1-19 Sprocket Wear on the Inside of the Links ................................................................................................................. 1-19 Wear in the Counterbore (Non-Lubricated Track) ...................................................................................................... 1-20 Link Rail Spalling ................................................................................................................................................. 1-20 Pin Boss End Wear of the Link ............................................................................................................................... 1-20 Counterbore Extension of the Link .......................................................................................................................... 1-20 Link Crack .......................................................................................................................................................... 1-20 IDLER WEAR .......................................................................................................................................................... 1-21 Idler Tread Surface Wear ...................................................................................................................................... 1-21 Idler Flange Side Wear ......................................................................................................................................... 1-21 Idlers ................................................................................................................................................................. 1-21 TRACK ROLLER AND TRACK CARRIER ROLLER WEAR ............................................................................................. 1-22 Flange Wear ....................................................................................................................................................... 1-22 Track Rollers and Carrier Rollers ............................................................................................................................ 1-22 Bur 6-80040

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ii TRACK SHOE WEAR ............................................................................................................................................... 1-23 Grouser Wear ...................................................................................................................................................... 1-23 Cracked or Broken Shoes ...................................................................................................................................... 1-23 Bolt Holes Too Large ............................................................................................................................................ 1-23 NON-LUBRICATED TRACK ...................................................................................................................................... 1-24 Turning Pins and Bushings (Non-Lubricated Track) ................................................................................................... 1-24 LUBRICATED TRACK .............................................................................................................................................. 1-25 Turning Pins and Bushings (Lubricated Track) .......................................................................................................... 1-25 Marking the Pins and Bushings (Lubricated Track) .................................................................................................... 1-25 Track Bushings (Forward and Reverse Wear) - Sealed .............................................................................................. 1-26 Track Bushings (Vertical Wear) .............................................................................................................................. 1-26 TRACK TENSION .................................................................................................................................................... 1-27 Extended Track Pitch (Length) - Non Lubricated Track Only ....................................................................................... 1-27 Track Tension ..................................................................................................................................................... 1-27 Other Conditions .................................................................................................................................................. 1-27 Correct Tension ................................................................................................................................................... 1-27 Bushing and Sprocket Wear Chart .......................................................................................................................... 1-27 Track Link Height ................................................................................................................................................. 1-28 Procedure to Adjust the Track ................................................................................................................................ 1-28 To Tighten the Track Chain ................................................................................................................................... 1-28 DC70 DOZER WEAR CHARTS .................................................................................................................................. 2-29 DC75 DOZER WEAR CHARTS .................................................................................................................................. 3-33 Non-Lubricated Track ........................................................................................................................................... 3-34 Lubricated and Non-Lubricated Track ...................................................................................................................... 3-35 DC80 DOZER WEAR CHARTS .................................................................................................................................. 4-39 DC85 DOZERS ....................................................................................................................................................... 5-43 Non-Lubricated Track ........................................................................................................................................... 5-44 Lubricated and Non-Lubricated Track ...................................................................................................................... 5-45 DC95 DOZER WEAR CHARTS .................................................................................................................................. 6-49 Non-Lubricated Track ........................................................................................................................................... 6-50 Lubricated and Non-Lubricated Track ...................................................................................................................... 6-51 DC100 DOZER WEAR CHARTS ................................................................................................................................ 7-55 DC150 DOZER WEAR CHARTS ................................................................................................................................ 8-59 Lubricated Track .................................................................................................................................................. 8-59 DC180 DOZER WEAR CHARTS ................................................................................................................................ 9-63 Lubricated Track .................................................................................................................................................. 9-63 GLOSSARY .......................................................................................................................................................... 10-67 TRACK COMPONENT APPRAISAL FORM ................................................................................................................ 11-71

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CRAWLER UNDERCARRIAGE COMPONENTS Undercarriage components make up a major cost of purchasing, owning and maintaining a crawler dozer.

Equipping a dozer properly with the right undercarriage components can maximize up time productivity and minimize operating expenses. In selecting the proper undercarriage items such as application usage, soil conditions, types of chain assemblies, sprocket types, shoe widths, and maintenance practices should be reviewed with your customer.

New Holland Construction offers several choices to fit a variety of applications and needs: NEW HOLLAND CONSTRUCTION SEALED TRACK: This assembly is a non-lubricated system between the pin and bushing. To prevent contamination from entering into the pin and bushing area, metal seals are located on both sides of each bushing. This option provides good wear life, but wear still occurs on the pin and on both inside and outside diameters of the bushing.

SHOE WIDTHS: Dependent on the machine, standard widths may vary from 16 inches to 34 inches. The shoes must provide adequate traction and flotation, but no wider than necessary. Flotation is the ability to stay on the surface of soft ground or mud. Correct flotation occurs when the grouser bar penetrates into the ground without letting the shoe go below the surface.

MAINTENANCE: Correct track tension is important.

Check the track tension frequently when operating.

When wor king in mud, snow, and some sandy conditions, check the track tension more often. A loose track or a track that is too tight will accelerate track wear.

NEW HOLLAND CONSTRUCTION LUBRICATED TRACK: This assembly is sealed (oil seals) and lubricated with an oil reservoir in each pin. Each pin and bushing are sealed to keep contamination out and lubrication in. This option provides excellent wear life.

Although wear between the pin diameter and inside bushing diameter is eliminated because of the lubricant, outside bushing wear still exists.

Abrasive Soils: Each type of soil a machine works in has a different level of abrasiveness. Generally, the higher the abrasiveness, the higher the wear rate.

Low Abrasiveness: Silts and clays are in this category.

When wet, this type of soil feels slick and can be easily molded.

Moderate Abrasiveness: Silts and clays that contain a low amount of rounded sand particles and enough moisture to stick together are in this category.

High Abrasiveness: These soils contain a high amount of sharp, irregular - shaped sand particles.

Impact: Impact is best described as the amount of grouser penetration on the ground. The effect of high impact loads can be reduced by reducing the machine speed and by using the smallest track shoes possible.

SPROCKET TYPES: Types include standard for most applications and wide track option relieved which is to be used in extrudable material.

Low Impact: Track shoe grousers will completely penetrate the ground surface with little or no rock or other irregularities.

High Impact: Track shoe grousers will not penetrate the ground surface. Large rock or large irregularities cause high impact loads on the undercarriage system.

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UNDERCARRIAGE COMPONENTS AND WEAR

UNDERCARRIAGE WEAR AND MEASUREMENT This section is to help you understand how track wear occurs and what you can do to get the most out of your undercarriage components.

Monitoring wear is one of the three main elements in maximizing an undercarriage investment. Monitoring wear helps anticipate when to make the pin and bushing turn and when to service or rotate components.

Also, by measuring wear and using the wear charts that are available for your machine, you will be able to determine the remaining life of all the components.

Record Keeping The undercarriage parts are measured to determine the amount of wear and to tell when repairs or replacement of parts is required. Keeping a good record of these measurements can tell you when your machine will be taken out of production for service.

The special forms for recording measurements and other information are available from your New Holland Construction dealer (Form Number 75300499).

When a customer buys a new piece of tracked equipment, approximately 20 percent of the purchase price is in the undercarriage. As repairs become necessary, approximately 50 percent of the overall maintenance cost will be maintaining the undercarriage.

With this type of expense, the owner or end user will greatly benefit from a detailed explanation of how undercarriage life can be extended.

Track Measuring Tool Kit

_JCB2113 D

380040176 Measuring Tools Kit The special tools shown are used to measure the wear of track system components.

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Before Measuring

Track Simulator

Make sure that you clean each component before you make the measurement. Use the scraper tool that is provided with the kit and a piece of emery cloth is necessary.

We will be using the New Holland Construction Track Simulator to demonstrate the varying conditions of track wear.

Each time you measure an undercarriage, carefully record all measurements on the Track Component Appraisal Form. Complete the report by comparing your measurements with the percent worn charts. Then record the wear life percentage remaining.

Replacement of worn components with new parts is one solution to undercarriage wear. However, there are other methods to prolong the life of your undercarriage.

Rebuilding Rebuilding is the process of welding or adding material to the worn surfaces of a component. Then the component is machined to original dimensions. Rebuilding is an alternative to replacing with new parts. While rebuilding is an inexpensive way of gaining additional life from worn components, this is not a recommended practice for small undercarriage parts. The extreme heat created by welding can cause warpage or changes in the molecular structure. Always use an experienced rebuild shop.

B921008

New Holland Construction Track Simulator New track components must never be used or mixed with worn track components. Mixing new undercarriage components with worn ones will greatly decrease the life of the new components and accelerate the wear of the worn parts.

Repositioning Repositioning is a method of extending the life of worn components. In addition to turning the pins and bushings, you can also change the sprockets from side to side. This is only if the reverse wear is much greater than the forward wear.

The front and rear track rollers will generally wear faster than the middle rollers. If they are all the same type (single flange or double flange), it is possible to rotate the rollers. See the service manual for your machine for the correct procedure.

If the machine has been run on a side slope for an extended period of time, the wear patterns can differ from one side of the machine to the other. The same can be true of the undercarriage that is not aligned correctly.

Additional life can be obtained by moving undercarriage components from one side to the other.

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UNDERCARRIAGE COMPONENTS AND WEAR

UNDERCARRIAGE COMPONENTS

BD04F071B

To fully understand the undercarriage, it is important to understand the purpose of each component. It is also very important to know how that component functions with the other components in the system.

8. TRACK FRAME - The track frames are attached to the machine chassis on each side. All of the track components except the drive sprockets are attached to the track frames.

1. DRIVE SPROCKET - The drive sprockets transmit engine power to the tracks. The drive sprockets do not support the weight of the machine.

9. TRACK LINKS - A number of track links make up the track chain assembly. Each link assembly consists of a right-hand and a left-hand link, a track pin (solid with sealed track chains and hollow with SALT. track chains), bushings and seals.

Each link assembly is bored at both ends to hold the pins and bushings that connect the two links.

The bushing is pressed into each link. A pin is inserted through the bushing and the next set of links is pressed onto the pin. Sealed Track and Lubr icated Track Chains are illustrated on page 1-25.

2. CARRIER ROLLER/S - The carrier roller/s are mounted on the top of the track frame to support the track chain between the drive sprocket and idler. This roller also helps to maintain alignment of the chain between the idler and drive sprocket.

3. TRACK CHAIN - The track chain includes a number of link assemblies that are connected together to form a complete chain. Shoes are bolted to the track chain to provide traction for the machine. The drive sprocket rotates the track chain around the undercarriage assembly.

4. IDLER - The idler carries the track chain around the front of the track frame. This assembly can slide forward or rearward on the track frame against the recoil spring to absorb any shock loads. These shock loads can be from changes in the terrain or temporary material buildup on the track chain or sprockets.

5. TRACK ADJUSTER - The track adjuster is a grease filled hydraulic cylinder used to maintain or adjust track tension. To change track tension, add grease or remove grease from the track adjuster.

NOTE: It is important to understand the construction of the track chain. The pins and bushings of the sealed track are generally the first items of the undercarriage to wear. This wear can (and will) affect the rest of the components in the system. This will be further discussed in the section Wear Patterns.

10. TRACK SHOES - The track shoes are installed on the track chain to give traction and flotation for the machine.

11. TRACK GUIDES - The track guides help to maintain alignment of the track chain and protect the track.

6. RECOIL SPRING - The recoil spring is used as a shock absorber that cushions large impact loads and also aids in maintaining correct track tension.

7. TRACK ROLLERS - The track rollers are mounted to the bottom of the track frame. These rollers carry the weight of the machine on the track chain.

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UNDERSTANDING UNDERCARRIAGE WEAR The factors that affect wear are very diverse. The most important wear factor is track tension, but other factors like speeds, soil conditions, the operator, the size of the machine, and high or low impact ground surface are also variables that affect wear.

You cannot stop undercarriage wear - even if you have the best design and top quality parts. You can, however, extend the undercarriage life if you understand the causes of wear.

Wear You Can Not Control

Packing mater ials cause a mismatch between components, par ticularly between the chain and sprocket. The packing materials tighten the chain. This causes increased stress and strain on links, pins, bushings and the contact surfaces between mating parts.

For example, as mismatch occurs due to packing in the sprocket root, each track bushing rides higher in the sprocket. This condition causes rapid and severe forward and reverse wear and chain-to-sprocket “jumping” that is indicated by a loud “banging” noise. This results in high impact loads that cause additional wear and cracking.

Soil and underfoot conditions cannot be controlled.

These include abrasive soils, impact, packing, and moisture.

ABRASIVE SOILS Each type of soil a machine works in has a different level of abrasiveness. Generally, the higher the abrasiveness, the higher the wear rate.

Moisture also plays a major roll in abrasiveness of soils.

A sand slurry will be less abrasive than a damp sand, especially if that sand is packing in the sprocket roots and around the bushings. Wet abrasives act like grinding compounds.

LOW ABRASIVES - Silts and clays are in this category.

When wet, this type of soil feels slick and can be easily molded.

MODERATE ABRASIVE - Silts or clays that contain a low amount of rounded sand particles and enough moisture to stick together are in this category.

HIGH ABRASIVE - These soils contain a high amount of sharp, irregular shaped sand particles.

IMPACT Impact is best described as the amount of grouser penetration in the ground. The effect of high impact loads can be reduced by reducing the machine speed and by using the smallest track shoes possible.

LOW IMPACT - Track shoe grousers will completely penetrate the ground surface with little or no rock or other irregularities.

HIGH IMPACT - Track shoe grousers will not penetrate the ground surface. Large rock or large irregularities cause high impact loads on the undercarriage system.

Rocky terrain causes bending, breaking and chipping of the components. Reduce the machine speed and use the smallest track shoes possible.

PACKING Packing materials are any materials that stick to or pack around the moving components. To maintain correct track tension, the tracks must be adjusted as often as required when working in this type of soil condition.

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B408629V

This packing condition can also stop rollers from turning.

When this happens, the track chain slides over that spot on the roller. This sliding causes a flat spot on the roller.

Packing materials increase the abrasive effect of most material by not allowing the material to escape. Wear is then accelerated. Open center grousers or special relieved sprockets may help alleviate this problem.

Wear You Can Partially Control APPLICATIONS - The term “Applications” is often used to describe underfoot conditions. In this section we will describe what the machine is doing without regarding the applications.

DOZING - This operation shifts the machine weight to the front causing a faster wear rate on the front rollers and idlers.

SPEED - Unnecessary speed directly affects the wear rate on pins, bushings and sprockets. The faster the speed, the faster the wear rate. High speed reverse accelerates bushing and sprocket wear. Wear rate is a function of speed and distance travelled, not just hours worked.

IMPACT - High speed will increase impact loading when there is low grouser penetration on hard surfaces or when working in rock.

Impact can cause structural problems such as bending, cracking or breakage of components. This can also affect pin and bushing retention and bushing cracking. And, if a chain is worn, can cause fractures.

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UNDERCARRIAGE COMPONENTS AND WEAR

TURNING - Wear rate increases when tracks are slipping. Track shoe grousers are affected due to increased sliding between grouser and the ground.

TRACK SLIP - Wear rate on all components increases when tracks are slipping. Track shoe grousers are affected due to increased sliding between the grouser and the ground.

The machine weight is moved forward causing increased wear of the front rollers. However, due to the design of the track system, working downhill reduces the wear of the sprockets and bushings.

WORKING ON THE SIDE OF THE HILL

FAVORED SIDE OPERATION - Wear rates will increase on all components when only one side of the machine is favored. Wear increases as more power is applied to the favored side. Also, more packing and slipping will occur on the favored side.

REVERSE OPERATION - Avoid excessive use of reverse operation. This is not only non-productive use of the machine, but it also accelerates bushing and sprocket wear. See page 1-11 and page 1-14.

RIPPING, PULLING IMPLEMENTS, OR USING A HITCH OR WINCH TO PULL LOADS - This operation will shift the machine weight toward the rear, causing a faster wear rate on the rear rollers. Then, during severe applications, the sprockets and track bushings wear much faster.

BS97013

This moves the weight of the machine toward the downhill side of the machine. Wear is increased on the rail sides, roller and idler flanges, bushing ends, and track shoe ends that are on the downside of the hill.

WORKING ON A CROWN

TERRAIN Changes in the terrain change the attitude of your machine. This condition shifts the center of gravity and increases the weight of the machine on different parts of the undercarriage.

WORKING UPHILL

BS97N014

The inner components carry the heaviest load. The wear is increased on the inner links, roller treads, idler treads, and track plate ends. In extreme situations, the inner sprocket/bushing wear is greatly increased.

WORKING IN A DEPRESSION

BS97N011

This condition moves the weight of the machine rearward causing increased wear of the rear rollers and increased forward drive wear of the sprockets and bushings.

WORKING DOWNHILL

BS97N015

The outer components carry the heaviest load. The wear is increased on the outer links, roller treads, idler treads, and track plate ends. In extreme situations, the outer sprocket/bushing wear is greatly increased.

CLEAN TRACKS

BS97N012

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W h e n t h e d ay i s f i n i s h e d , a l way s c l e a n t h e undercarriage. Park the machine on a level surface to prevent distortion of the track seals. If the temperature is cold, park the machine on a surface that will not freeze to the track shoes.

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● Decreased pin and bushing life, or decreased link life

Wear You Can Control Good operating techniques and a good maintenance program will help you to get the longest life from your undercarriage.

due to elongated pin and bushing bores. This is a result of the twisted links. ● Possible loss of lubricant in the Lubricated Track. This

will result in early pin and bushing wear.

TRACK TENSION

TRACK ALIGNMENT

Check the track tension frequently when you operate.

When working in mud, snow and some sandy conditions, check the track tension more often. Material will pack on the undercarriage parts and cause the tracks to become too tight. Always maintain the correct track tension and always clean the undercarriage when you are done for the day. See page 1-27 for complete information on track tension and track adjustment.

Correct track alignment is required to prevent early wear of the undercarriage components. When you replace parts of the track system, always see the service manual for your machine and check the alignment of the undercarriage components.

B920692

BD04B062

TRACK SHOES The shoes must provide adequate traction and flotation but must be no wider than absolutely necessary.

Flotation is the ability to stay on the surface of soft ground or mud. Correct flotation occurs when the grousers penetrate fully into the ground without letting the track shoes go below the surface.

Track shoes that are too wide can have a damaging effect on many of the undercarriage components.

Because the middle of the track shoe is fastened to the track links, the links act as a fulcrum and must absorb or transmit any leverage or twisting forces that occur as the machine moves over uneven or rocky terrain. All of the other components (sprockets, track rollers and idlers) resist and restrict the twisting forces of the links. As a result, most of the wear and damage caused by the twisting action affects the links, pins, bushings and track plate mounting hardware.

Listed below are some of the effects of wide track shoes: ● Resistance to turning - results in wear on the shoe

corners and twists the track chain. ● Bending, cracking or breaking the track shoes, shoe

Misalignment problems will affect more of the undercarriage components than any other cause of wear. Misalignment will cause accelerated wear on the track links, idler flanges, track and carrier roller flanges, sprockets and rock guards. Alignment problems can be caused by all of the following: ● Bent or twisted track frames that are not parallel or

perpendicular to the centerline of the machine.

Realign, repair or replace damaged or misaligned track frames as required. ● Idlers that are misaligned vertically or horizontally or

are not in line with the sprocket and carrier rollers.

Realign the idlers. ● Sprockets that are not shimmed correctly or are not in

line with the track and carrier rollers. Realign the sprockets. ● Carrier rollers that are not in line between the sprocket

and idler. Realign the carrier rollers.

IMPORTANT: Tight tracks will greatly increase the effect of misalignment by causing an increase in load between the components. Track tension must be checked on a regular basis - more often during packing conditions. See page 1-27 for the correct procedure to check and adjust the track tension.

hardware and links. ● Constant

problems with loose shoe hardware that makes the bolt holes larger.

● Increased

wear on links, roller flanges and idler flanges caused by constant twisting of the track chain.

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UNDERCARRIAGE COMPONENTS AND WEAR

EXTENDING UNDERCARRIAGE LIFE Track Adjustment and Inspection Eliminating or reducing the controllable causes of wear is a primary factor in extending the life of the undercarriage.

Proper care and maintenance is the simplest and most cost effective method of extending undercarriage life.

Conscientious scheduled maintenance and good operating habits will help keep operating costs and downtime to a minimum.

Now that you know the major factors contributing to track wear, here are a few operating and maintenance tips to help you get the most life from your machine’s undercarriage.

● Avoid frequent reverse operation. If necessary to work

in reverse, keep travel speed to a minimum. ● Constantly turning the crawler in the same direction

will cause uneven wear. ● Make sure that rock guards are installed before you

operate in rocky conditions. Remove the rock guards before operating in packing conditions. ● In

freezing temperatures, clean the undercarriage more frequently and park the machine on planks or on a surface that will not freeze to the machine.

● Keep the machine turns to a minimum. Turning adds

stress and side wear to the components.

Undercarriage wear is an inevitable part of owning a track machine. Sooner or later, even the best undercarriage will need to be replaced.

● If possible, match the track shoes to the underfoot

You can prolong undercarriage life by understanding the factors that contribute to wear.

● Soil conditions are a major factor in determining the

conditions. Use the smallest track shoe possible that will give good traction and flotation. amount of life you can expect from an undercarriage.

Nonabrasive soils, such as silt and clay, cause the least amount of wear. Wet, sandy soils are the most abrasive and cause the most wear.

Operating techniques and maintenance also greatly affect undercarriage life. Unlike the other wear factors that you can not control, you can do something about the way you operate and maintain the machine.

● Working in rocky conditions and other surfaces, where

If you are serious about reducing the maintenance and repair of your undercarriage, follow these tips.

the grouser bars do not penetrate, causes high impact and twisting loads on the track chains.

● Visually inspect the machine each day for leaking

● Minimize the effects of packing by checking track sag

rollers and track pins. ● Check and adjust the track tension on a regular basis,

especially as job and soil conditions change. ● Keep

frequently when working in mud, snow, and wet sand.

Packing can cause track jumping and banging. ● Severe packing of materials between undercarriage

components causes wear by increasing track tension.

the tracks as clean as possible. Packing materials and abrasives will both accelerate the wear process.

● Running tracks that are too tight reduces bushing and

● Check for loose or missing hardware on a regular

● When possible, work up and down a slope instead of

basis and replace all missing or damaged parts.

Tighten all bolts to the recommended specifications.

across it. This decreases wear on roller flanges and link side rails.

● Tracks that are too tight rob power and cause early

● Check track tension and clean the undercarriage more

bushing and sprocket wear. Periodically check tracks for correct tension.

frequently when working in high packing conditions.

sprocket life 2.5 to 3 times.

● Use the smallest track shoes possible to minimize

● Speed,

track chain twisting. Limit the use of wide track shoes to high flotation applications.

● Avoid

● Park the machine on level ground to prevent seal

impact, turning and direction of operation greatly affect wear. high speed operation whenever possible, particularly in rough terrain.

● Avoid

spinning the tracks as much as possible, especially in abrasive soil conditions.

● Do not spin or slide the tracks. Apply the power and

stop the machine gradually. ● If possible, avoid reverse operation, especially high

speed reverse operation.

distortion (Sealed and Lubricated Track). ● Turn the pins and bushings at the 100% wear limit.

Operating past the 100% wear limit can cause the bushings to crack or to wear completely through to the pin. ● Letting the pins and bushings run to destruction results

in accelerated wear of other components. Turn the pins and bushings to extend track life.

● Avoid long runs at high speed and limit the amount of

reverse travel.

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SPROCKET WEAR AND MEASUREMENT Sprocket tooth wear is the most obvious of all wear patterns. Track bushing wear is not as obvious but still must be considered when evaluating corrective action.

5

Clean Track When the undercarriage is clean, each bushing seats against a sprocket tooth. The bushing is engaged at the 6 o’clock position and carries approximately 85% of the driving load. At 5 o’clock the load is reduced on this bushing to 10% and at 4 o’clock down to 5% of the drive load.

2 3

1 3

4 B912376

2

1. BUSHING AND DRIVE TOOTH ENGAGED (AT 3 O’CLOCK) 2. PACKING ON THE DRIVE SPROCKET 3. ORIGINAL CHAIN PITCH 4. CHAIN PITCH WHEN PACKING STARTS 5. LEFT DRIVE SPROCKET

1

SEVERE PACKING

B912375

1. TRACK CHAIN AND SPROCKET ARE ON THE SAME PITCH DIAMETER 2. BUSHING AND DRIVE TOOTH ENGAGED (AT 6 O’CLOCK) 3. LEFT DRIVE SPROCKET

SPROCKET BEGINS TO PACK A material begins to pack into the sprocket teeth, the bushing must be engaged at a higher position on the tooth. See the following illustration. The first bushing will be seated against a tooth and there will be a space between the next bushing and tooth. As the sprocket rotates, each bushing that is to be engaged will be progressively further from the driving tooth.

The first bushing continues to receive the full load as the sprocket rotates. When this bushing leaves the sprocket, the track chain will re-seat on the sprocket. This reseating results in the bushing impacting against the sprocket tooth. At the same time, the increased track tension causes the track recoil spring to be compressed.

As the bushing re-seats, the impact of the bushing along with the release of the recoil spring causes a loud “banging” noise.

Bur 6-80040

When severe packing occurs, bushing engagement starts much later in the sprocket rotation, around 1 to 2 o’clock. The chain pitch is increased to the maximum. As a result, (1) the chain is tightened, (2) the recoil spring is compressed and, (3) bushing engagement moves out to the tip of the sprocket tooth. The driven bushing continues to receive full load until this bushing leaves the sprocket tooth. At that time the track chain seats again on the sprocket. At the same time, the recoil spring is released against the stop and a loud noise is heard.

This severe packing condition can also cause the chain bushing to climb up and go over the top of the sprocket tooth. This condition, called jumping, will also cause a loud noise.

The best action to take is to loosen the tracks to the correct tension. Or, you can install special relieved drive sprockets if the packing material is extrudable. The special relieved drive sprockets will help to clean material from the sprocket root.

NOTE: Special relieved drive sprockets can reduce the life of the track chain bushings as there is less contact area on the sprocket.

All New Holland Construction Sealed and the Lubricated track chains use a “hunting-tooth” design drive sprocket with an odd number of teeth. This design causes each tooth to make contact on every other revolution. We use the same sprocket for non-lubricated track as well as the lubricated track.

Issued 08-05

Printed in U.S.A.

1-10

UNDERCARRIAGE COMPONENTS AND WEAR

Sprocket Wear Patterns 1

FORWARD DRIVE SIDE WEAR OF SPROCKET, BUSHINGS, AND PINS

6

3 4 2 5

B921009

1. With new sprocket, pins and bushings, there is a correct match between the sprocket and the bushings in the 6 o’clock position.

2. The track bushing to sprocket contact area is 60%.

3. There is not any movement between the sprocket and bushing until the bushing leaves the sprocket.

At that point, wear is very small.

4. In the forward drive direction, the track pin is in the hinge point. Internal wear occurs between the outside diameter of the pin and the inside diameter of the bushing. This wear is greatly reduced with the Lubricated track chain.

5 B920084

1. BUSHING AND DRIVE TOOTH ENGAGED (AT 1 O’CLOCK) 2. CHAIN PITCH WHEN PACKING IS SEVERE 3. ORIGINAL CHAIN PITCH 4. SEVERE PACKING 5. TOOTH MOVING OVER BUSHING 6. LEFT DRIVE SPROCKET

INTERMITTENT PACKING - Packing can also occur between some of the sprocket teeth. When this happens, the track is tightened and released rapidly causing the recoil spring to compress and release. A loud “banging” noise will result.

EXTREME REVERSE LOADING - During this operation the machine is backing up a hill and the top of both track chains are tight compressing the recoil springs. You suddenly drive the machine forward. The loud “banging” noise that you hear can be from one or both recoil springs releasing.

Bur 6-80040

B921010

In the forward drive direction, the track bushings carry: 1. 85% of the load at the 6 o’clock position.

2. 10% of the load at the 7 o’clock position.

3. 5% of the load at the 8 o’clock position.

Issued 08-05

Printed in U.S.A.

UNDERCARRIAGE COMPONENTS AND WEAR REVERSE DRIVE SIDE WEAR OF THE SPROCKET AND BUSHINGS

1-11

VERTICAL WEAR OF THE BUSHINGS AND SPROCKETS

B921011

B921013

● This is the most severe of all bushing and sprocket

● This wear results when the bushing slides back and

wear. The sprocket teeth make contact with the bushings at 12 o’clock. Most of the torque required to move the machine is transferred at this point.

fourth in the sprocket.

● The track chain bushing becomes the hinge point in

reverse drive operation. ● Reverse drive must be kept to a minimum. If reverse

drive is required, reduce the speed.

B921014

● Frequent forward and reverse shifting accelerates this

wear.

REVERSE TIP WEAR

B921012

● There

are three wear/movement points in the REVERSE direction as opposed to one in FORWARD: A. Sprocket scuffing from the bushing B. Bushing scuffing and rotation C. Internal pin and bushing wear

B921015

● This is the most severe of all outer diameter bushing

wear situations. ● This only occurs in the forward drive direction. ● The bushing outer diameter contacts the reverse tip of

the sprocket. ● This wear occurs due to packing of the sprocket root.

Bur 6-80040

Issued 08-05

Printed in U.S.A.

1-12

UNDERCARRIAGE COMPONENTS AND WEAR TURNED TRACK PINS AND BUSHINGS WITH NEW SPROCKET (SEALED AND C.L.T. ONLY)

B921016

● The pitch of the track chain no longer matches the

pitch of the sprocket and “snapping” or “popping” of the track occurs.

NEW SPROCKET WITH WORN TRACK PINS AND BUSHINGS

B921020

● Turned track pins and bushings will create an almost

new condition.

B921021

● This returns the sprocket pitch and track chain pitch to B921017

● The sprocket pitch no longer matches the track pin and

bushing pitch. ● This is a result of the contact area being moved farther

a correct match.

NEW PINS AND BUSHINGS WITH WORN SPROCKET

up on the sprocket tooth.

B921022 B921018

● Again,

never interchange old undercarriage components with new to try to correct any condition.

● The new track pins and bushings will not match the

worn sprocket pitch. ● The worn sprocket teeth no longer match the track

pitch - this accelerates wear.

Bur 6-80040

Issued 08-05

Printed in U.S.A.

UNDERCARRIAGE COMPONENTS AND WEAR

1-13

B921023

● Worn sprocket teeth can be seen as pointed teeth. ● Again,

never interchange old undercarriage components with new to try to correct any condition.

WORN PINS AND BUSHINGS WITH WORN SPROCKET

B921019

● The surface contact is greatly reduced. ● Accelerated wear will occur due to lack of contact area

until the track pins, bushings and sprockets are destroyed.

3 1

You must now decide whether to turn the pins and bushings and install new sprockets or r un the undercarriage to destruction.

SPROCKET REVERSE TIP WEAR (MACHINE TRAVELLING FORWARD) Reverse tip wear is due to material packing conditions.

As the material builds up on the sprocket, the chain pitch no longer matches the sprocket teeth. The sprocket tooth contacts the bushing as the chain moves into the sprocket. Wear is on the reverse side tip of the sprocket tooth and the bushing.

Bur 6-80040

2 B912293

1. REVERSE TIP WEAR OF THE SPROCKET CAUSED BY PACKING 2. BUSHING WEAR CAUSED BY THE SPROCKET TOOTH 3. MATERIAL PACKING IN THE SPROCKET ROOT

Issued 08-05

Printed in U.S.A.

1-14

UNDERCARRIAGE COMPONENTS AND WEAR

SPROCKET REVERSE DRIVE SIDE WEAR (MACHINE TRAVELLING IN REVERSE)

SPROCKET FORWARD OPERATION WEAR (MACHINE TRAVELLING FORWARD)

Reverse drive side wear can be the most severe wear you can have with the sprocket teeth and bushings.

When moving in reverse, the sprocket teeth contact the chain bushings at about 12 o’clock. Most of the torque required to move the machine is transferred to the track chain between 12 and 11 o’clock. During this time, the bushing is rotating against the sprocket. A pocket forms on the reverse side of the sprocket tooth where the rotating bushing is making contact. This contact causes accelerated wear, especially when the machine is moving at high speed.

When driving forward, the sprocket teeth contact the bushings at about 6 o’clock. Most of the torque required to move the machine occurs at this point. The bushing does not rotate against the sprocket until leaving the sprocket at about 11 to 12 o’clock.This is normally not a critical wear factor because the torque was transmitted at the 6 o’clock position. It becomes a problem only when track tension is too tight.

2

1 1

2

B912298

1. FORWARD WEAR OF THE SPROCKET 2. FORWARD WEAR OF THE BUSHING

B912297

1. REVERSE WEAR OF THE SPROCKET 2. REVERSE WEAR OF THE BUSHING

Bur 6-80040

Issued 08-05

Printed in U.S.A.

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