Transmission Overhaul Estimator Guide{0374, 3150} Caterpillar

Transmission Overhaul Estimator Guide{0374, 3150}

Usage:

Introduction

This guide is to be used with the PEEP0007, Transmission Evaluation Worksheet.

Each area of the worksheet will be explained to assist in:

* Evaluation, judging or rating a machine application.

* Operator technique.

* Transmission performance and inspection of transmission components.

* Verifying maintenance intervals and related maintenance items.

Using the Transmission Evaluation Worksheet

Customer and Machine Operation

It is essential that this section of the worksheet be completed in full for proper documentation. This information will allow you to begin a history file, by machine, that may be referenced later.

It also contains key information to assist your Service Department should they be required to further inspect the machine or conduct repairs.

The questions in this section are related to the machine application and its operating environment. These questions are required for the Transmission Overhaul Estimator Guide calculations.

The question regarding load factor assigns a rating to the amount of time that maximum rated engine power is being transmitted through the transmission.

In this guide, the type of load factor (heavy, medium, and light) is determined by observing the machine and using your best judgment.

The following descriptions will assist in rating the particular machine application being evaluated.

NOTE: The load factor description may also be found in the Performance Handbook, SEBD032.

Track Type Tractors

Application

Heavy: Steady ripping, agricultural drawbar work at full throttle; little or no idle.

Little travel in reverse, unless pushing a scraper or ripping for short lengths.

Medium: Production dozing, pulling scrapers, shuttle pushloading.

Light: Considerable idle or travel with no load.

Pipelayers

Application

Heavy: Steady cycling, little or no idle time.

Medium: Normal cycling, less than 50% idle time.

Light: Light duty utility with 50 % or more idle time.

Off-Highway Trucks

Application

Heavy: Long haul times with frequent unfavorable grades.

Steady cycling with little or no idle time.

Haul roads are poorly maintained with high rolling resistance.

Medium: Normal load and haul tires.

Some adverse grades.

Varying load and haul road resistance.

Light: Short to medium hauls on well maintained roads.

Minimum total resistance.

Articulated Dump Trucks

Application

Heavy: Long haul times with frequent unfavorable grades.

Steady cycling with little or no idle time.

Haul roads are poorly maintained with high rolling resistance.

Medium: Normal load and haul times.

Some adverse grades.

Varying load and haul road resistance.

Light: Considerable idle time.

Short-to-medium hauls on well maintained roads.

Minimum total resistance.

NOTE: Duty does not include transfer gear life.

Wheel Tractor-Scrapers

Application

Heavy: Continuous high total resistance conditions with steady cycling.

Medium: Typical road building use.

Light: Average use but with considerable idling, favorable grades, low rolling resistance and easy loading material.

Wheel Loaders and Integrated Toolcarriers

Application

Heavy: Steady cycling on the basic loader cycle.

Medium: Steady cycling over haul distances or work on basic loader cycle with frequent periods of idle.

Light: Light utility work

Considerable idle.

Wheel Dozers and Compactors

Application

Heavy: Heavy dozing, compacting heavy material.

Medium: Production dozing, most pushloading, shovel cleanup, normal compaction.

Light: Considerable idle or travel with no load.

Motor Graders

Application

Heavy: Ditching, fill spreading, spreading base material, ripping, heavy road maintenance and snow plowing.

Medium: Average road maintenance, road mix work, scarifying, snow plowing.

Light: Finish grading, light maintenance, road travel.

Skidders

Application

518

Heavy: 6810 kg (15,000 lb) in steep terrain (10% or greater) with high skidding resistance.

Medium: 4540 to 6810 kg (10,000 to 15,000lb)

Light: Skidding small loads in flat terrain with low skidding resistance.

528

Heavy: 11350 kg (25,000 lb)

Medium: 6810 to 11350 kg (15,000 to 25,000 lb) in steep terrain (10% or greater) with high skidding resistance.

Light: Skidding small loads in flat terrain with low skidding resistance.

NOTE: Refer to the Performance Handbook, SEBD032 for the procedures to estimate material loads.

Feller Bunchers

Application

Heavy: Steady felling and bunching with little idle time.

Medium: Steady cycling with frequent periods of idle.

Light: Light easy work.

Considerable idle.

Backhoe Loader

Application

Heavy: Production work with long cycles and/or constant loader use.

Medium: General work with regular cycles in medium applications.

Light: Utility work with intermittent cycles in light to medium applications.

NOTE: Normal duty cycle for backhoe loaders is based on a 60% backhoe and 40% loader application.

Scheduled Oil Sampling (S·O·S)

If the customer is currently enrolled in the S·O·S program, the records should be reviewed to see if a problem/previous problems have been indicated.

Each report, from a Scheduled Oil Sampling Laboratory, will address problem areas and include recommendations.

Oil Sampling at 500 Hours

The recommended hour interval for most transmission oil samples is 500 hours.

That figure is the minimum interval at which the oil sampling should be sampled to use S·O·S as a diagnostic tool to insure that preventive measures can be implemented if the results of the sampling indicate abnormal wear or contamination.

Oil Sampling at 250 Hours

There are some machine owners participating in the S·O·S program who sample more frequently than 500 hours (at 250 hours intervals).

Under normal circumstances they usually experience even less unscheduled down time with their transmission.

Through shorter oil sampling intervals better maintenance is achieved with quicker reactions to potential problems.

Oil Sampling After 500 Hours

There are some machine owners who take their oil samples at intervals greater than 500 hours.

This can often result in more expensive repairs of transmission replacement.

The minimal cost of Scheduled Oil Sampling for repair before failure and scheduling downtime greatly outweigh the longer uptime between oil samplings.

None

None is the term for the machine owner who does not participate in the Scheduled Oil Sampling program.

Maintenance

Each Caterpillar machine has a recommended maintenance schedule that includes maintenance intervals, oil specifications, and oil viscosities recommendations.

Following the maintenance schedule will ensure the maximum service life and performance from the transmission before parts need to be repaired or replaced.

Excellent

If your maintenance practices exceed the recommendations, then your rating is Excellent.

Good

If you follow the maintenance recommendations without exceeding them, then your rating is Good.

Average

If you follow some recommendations and not others, then your rating is Average.

None

If you do not follow any recommendations, then your rating is None.

Oil Type

It is important that the type of oil used in the transmission be identified.

Cat TDTO

Maximum transmission service life and performance can be enhanced by using Caterpillar's Transmission/Drive Train Oil (Cat TDTO).

Cat TDTO oil is more stringently tested than any other oil, and it exceeds the standard TO-4 rating because of its three characteristics:

* It has optimal coefficient of friction

* It is more compatible with Caterpillar transmission parts .. and

* It provides longer gear life

TO-4

The transmission oil that is not a Cat transmission oil but has a standard TO-4 rating is listed on the Transmission Evaluation Worksheet as TO-4. It meets the basic requirements of the TO-4 specifications.

CD/TO-2

Previously, CD/TO-2 transmission oil was the basic oil that was recommended for a Caterpillar transmission. It satisfies the very minimum of requirements that Caterpillar places on transmission oil.

CD/TO-2 Beyond Rating

Show/hide table

NOTICE

Any oil that is less than the CD/TO rating is not approved for a Caterpillar transmission and as a result of its use, maximum transmission life can be shortened. Multi-viscosity oils or CD/TO-2 oils used outside the ambient temperature range can also shorten the life of the transmission.

Wear Fatigue

An estimation that determines the degree of wear/fatigue can be determined by rating the amount of time spent in limited speed ranges opposed to spreading the load through the normal operating range.

Normal

If an operator uses every speed range regularly during the course of the work, then the transmission will experience Normal wear/fatigue.

High

If an operator uses a limited speed range, then the transmission will experience High wear/fatigue.

NOTE: The range of speed selection is dependent on the machine model and application.

Example:

A motor grader can have, depending on the model, six or eight forward speeds. During its normal operation only the lower speed ranges are frequently used for any prolonged period of time. So it is Normal for a motor grader to not use its full range of speeds evenly.

The Challenger 65 and 75 during tilling application, track-type tractors during ripping application, and wheel tractors (824 and 834) have similar wear/fatigue characteristics to the motor grader.

Example:

An off-highway truck traveling on a long steep grade using the lowest speed range will experience High wear/fatigue.

Scrapers and articulated dump trucks have similar wear/fatigue characteristics to the off-highway truck.

Shift Frequency

Frequent shifting accelerates wear. If there has been a high frequency of shifting, accelerated wear might be apparent.

Note the frequency of shifts as compared to normal for a given machine model in a normal application.

Normal

If there has been a normal frequency of shifting, normal wear has occurred.

Example:

Motor Graders undergo very few speed changes during their normal operation.

The Challenger 65 and 75 during tilling application, track-type tractors during ripping application, and the larger models of the wheel loader have similar wear/fatigue characteristics to the motor grader.

High

If there has been a high frequency of shifting, accelerated wear might be apparent.

Example:

Off-Highway Trucks (when using short haul roads) have a high shift frequency.

Wheel Tractor-Scrapers have similar wear/fatigue characteristics to the off-highway truck.

NOTE: Instead of the shift frequency wear characteristics occurring in the speed gears as in the previous examples, there are machines that have wear characteristics occurring in the direction gears. These machines include track type tractors and the smaller models of wheel loaders.

Operator Technique

Operator technique is very important to the life of a transmission. The better the operator, the less wear imposed upon the transmission.

Excellent

An operator of a track type tractor who stops the machine before making directional shifts and uses the decelerator under load is rated Excellent.

Average

An operator who makes all straight directional shifts, and makes no split shifts or split directional shifts without using the decelerator is rated Average.

Aggressive

An operator who occasionally makes split directional and straight directional shifts at full throttle (without using the decelerator) and consistently pushes the machine to its limits is rated Aggressive.

Abusive

An operator who often makes split directional and straight directional shifts at full throttle (without using the decelerator) is rated Abusive.

NOTE: For an evaluation of the transmission with an abusive operator, your service department must be contacted for assistance.

Operator/Shift Variation

The number of operators and working shifts directly affects transmission life. Multiple operators working multiple shifts will likely produce the fastest wear.

Designation

A = A single operator working a single shift.

B = Multiple operators working in one shift.

C = Multiple operators working in multiple shifts.

Related Component Failures

Causing Transmission Overheating

Transmission overheating is not always caused by transmission component(s) failure.

Example:

A track-type tractor brake or torque convertor failure may cause transmission overheating.

NOTE: The operator and/or owners maintenance department should be consulted to determine the number of failures of related components which could have caused the transmission to overheat.

Causing Coolant Contamination and Requiring Transmission Flushing

Transmissions which have experienced cooling core failures resulting in coolant contamination and/or component failures requiring system flushing or cleaning should be evaluated by your service department.

Visual Transmission Inspection

Transmission Hoses

The general condition of the transmission hoses should be carefully inspected.

Are there any leaks in the hoses or connections?

Are there any wrinkles or surface ruptures on the hoses?

Are there any worn surfaces on the hoses?

Transmission Oil

Is the transmission oil at the proper level?

Type of Filter (Brand)

Are the filters recommended by Caterpillar?

Type of Oil

What is the brand of oil and viscosity?

Is the viscosity correct for the ambient temperature?

Breather

What is the general condition of the breather?

Does it need replacing?

Gauges/EMS Panel

Gauges

Are the gauges operable?

EMS Panel

Are all indicators in the EMS panel operable?

Transmission Evaluation

Oil Filter Analysis

A review of the S·O·S history of schedule of oil sampling will help in determining wear trends and will act as a guide for inspecting the filter.

The filters should be cut open for an internal inspection.

Inspect for:

* Debris (metallic and nonmetallic)

* Ruptured portions of the filter element

* Unusual concentrations of sludge or evidence of contaminated oil.

NOTE: A magnet can be used to separate (identify) ONLY some of the metallic debris. Some of the metals used in the transmission componets are nonferrous.