The Practical Handbook Of Machinery Lubrication 4th Edition //top\\ Guide

"The Practical Handbook of Machinery Lubrication (4th Edition)" by Noria Corporation serves as a definitive, 220-page field guide focusing on proactive contamination control and lubrication reliability. The text covers essential topics including lubricant failure analysis, grease application, and, as detailed in, modern storage and handling techniques. For more details, visit Noria Store Noria Store Machinery Lubrication Reference Guide - Noria Store

Mastering Reliability: A Deep Dive into The Practical Handbook of Machinery Lubrication (4th Edition)

In the world of industrial maintenance, lubrication is often dismissed as a simple task—just "greasing the bearings." However, any reliability engineer will tell you that improper lubrication is the leading cause of premature machinery failure. For those looking to move beyond guesswork and toward a world-class program, The Practical Handbook of Machinery Lubrication, 4th Edition, stands as the definitive industry "bible."

This updated edition remains the cornerstone for professionals aiming to master the complexities of modern tribology, oil analysis, and lubricant application. Why the 4th Edition Matters

The 4th edition isn't just a reprint; it is a comprehensive guide tailored to the evolving landscape of industrial technology. As machines become more precise and operate under higher stresses, the margin for error in lubrication narrows.

This handbook bridges the gap between high-level chemical engineering and the hands-on technician. It focuses on the "Five Rights" of lubrication: The Right lubricant In the Right place At the Right time In the Right amount With the Right attitude Key Pillars Covered in the Handbook 1. Lubricant Fundamentals and Base Oils

The 4th edition provides an exhaustive breakdown of base oil categories (Groups I-V) and how they interact with additives. Understanding the molecular difference between a mineral oil and a synthetic PAO is crucial for selecting the right fluid for extreme temperatures or high-load environments. 2. Modern Grease Application

Grease is more than "thick oil." The handbook explores the compatibility of different thickeners (lithium, polyurea, aluminum complex) and the physics of how grease bleeds oil into a bearing. This section is vital for preventing the common mistake of mixing incompatible greases, which can lead to catastrophic hardening or "soupy" runoff. 3. Precision Oil Analysis

One of the most valuable sections of the 4th edition is its approach to oil analysis. Instead of just reading a report, the book teaches you how to interpret data trends. You’ll learn how to identify:

Wear Debris: What specific metal shavings tell you about which component is failing. Contamination: Tracking moisture, soot, and silica.

Chemistry: Monitoring the depletion of additives and the rise of oxidation. 4. Storage and Handling

Lubrication excellence starts before the oil ever touches the machine. The handbook emphasizes "Clean, Cool, and Dry" storage. It provides practical layouts for lube rooms, the importance of desiccant breathers, and why filtering new oil—which is often "dirty" by modern standards—is a non-negotiable step for reliability. Who is This Handbook For?

Maintenance Managers: To build the business case for investing in better lubrication tools and training.

Reliability Engineers: To design preventive maintenance (PM) schedules based on science rather than manufacturer defaults.

CBM Technicians: To sharpen their skills in oil sampling and sonic greasing techniques.

ICML Candidates: This book is widely recognized as essential reading for those studying for the Machine Lubricant Analyst (MLA) or Machine Lubrication Technician (MLT) certifications. The Verdict: A Must-Have Resource

"The Practical Handbook of Machinery Lubrication, 4th Edition" is more than a reference book; it is a roadmap for cultural change within a maintenance department. It shifts the perception of a "oiler" from a low-skill position to a "Lubrication Technician," a vital guardian of plant uptime.

If your goal is to reduce unplanned downtime, extend the life of your assets, and save thousands in repair costs, this handbook is the most cost-effective tool you can add to your kit.

Are you looking to implement a specific lubrication program or perhaps prepping for an ICML certification exam?

Title: The Bible Just Got Better: A First Look at The Practical Handbook of Machinery Lubrication, 4th Edition

Subtitle: Why the new edition of the industry’s gold standard belongs on every reliability professional’s desk.

If you work in industrial maintenance, you already know the feeling. A critical bearing fails. A gearbox seizes. The oil analysis report comes back with “abnormal wear metals.” Somewhere, a simple lubrication mistake just cost your plant six figures.

For decades, the first line of defense against these failures has been a well-worn, grease-stained copy of The Practical Handbook of Machinery Lubrication.

Now, the team at Noria Corporation has done it again. The 4th Edition has arrived, and it is not just a fresh cover. This is a significant overhaul for the modern maintenance era.

The "Rules of Thumb" Section

Scattered throughout the margins are gold nuggets of pragmatic wisdom. For example:

• “The viscosity of oil changes roughly 5-7% for every 10°C (18°F) change in temperature.”
• “If an oil analysis report shows copper and tin, you have a bearing issue. If it shows iron and chromium, you have a cylinder issue.”
• “A typical rule for frequency: Grease every 500 hours of run time, or every three months—whichever comes first.”

Deep Dive: Core Content You Will Master

If you are considering purchasing this handbook, or if you already own it, understanding its architecture will help you leverage its power. The book is roughly 600 pages, divided into five logical pillars.

Conclusion: Why You Must Own the 4th Edition

Lubrication is a low-cost, high-return activity. A $500 mistake in lubricant selection can cause a $50,000 bearing failure and a $500,000 production loss. The Practical Handbook of Machinery Lubrication 4th Edition is the insurance policy against that scenario.

In a world where maintenance professionals are retiring and tribal knowledge is walking out the door, this handbook serves as the permanent, standardized archive of best practices. It tells you exactly when to change the oil, how to read the report, where to place the breather, and why the grease is leaking.

If you own the third edition, recycling it for the 4th Edition is a worthwhile investment—specifically for the IoT, ultrasonic, and ISO 4406 updates. If you have never owned a copy, you are currently practicing lubrication by folklore. It is time to practice by science.

Final Verdict: Essential reading. 5/5 stars. Keep a copy on your desk and a waterproof copy in your tool cart.

Call to Action: Check with major technical publishers such as Noria or Reliabilityweb for the latest printing of the 4th Edition. Ensure you receive the digital companion files if available, which include printable checklists and contamination control posters. Your machinery—and your bottom line—will thank you.

The "Grease" Between the Gears: Why Every Plant Needs the Practical Handbook of Machinery Lubrication

In the industrial world, lubrication is often seen as a simple "oil and grease" chore. However, the reality is far more complex: while lubrication makes up only about 2% of a maintenance budget, it is responsible for roughly 34% of mechanical failures when done poorly.

If you're looking to bridge the gap between "good enough" and "world-class reliability," the Practical Handbook of Machinery Lubrication, 4th Edition is your essential roadmap. What’s New in the 4th Edition?

Rewritten by industry veteran Robert Scott, this latest version transforms complex tribology into actionable, everyday advice.

Reliability Focus: The chapters have been restructured to focus specifically on how lubrication drives equipment reliability.

Enhanced Visuals: New high-quality graphics and illustrations make technical concepts—like how lubricants break down—easier to grasp at a glance. The Practical Handbook Of Machinery Lubrication 4th Edition

Modern Standards: The content is now closely aligned with Noria's certification training and ICML standards, making it the perfect study guide for professionals. Key Takeaways for Your Maintenance Team

The handbook doesn't just explain what to do; it explains why it matters for your bottom line.

Lubricant Selection & Additives: Learn the "four hard-fast rules" for determining if after-market additives are actually worth the investment.

Contamination Control: Get a blueprint for managing the "five destructive conditions" that can ruin even the highest-quality "super lubricants".

Troubleshooting & Testing: From oil analysis to identifying wear mechanisms, the book provides a 14-item checklist for any hydraulic or lubricated system. Why It Matters

Effective lubrication can reduce maintenance costs by up to 60% and significantly lower energy consumption—nearly 20% of the world's energy is spent just overcoming friction.

The Practical Handbook of Machinery Lubrication - 4th Edition

The Practical Handbook of Machinery Lubrication (4th Edition)

is a primary reference manual for maintenance and reliability professionals, widely regarded as a foundational resource for practical lubrication theory. Noria Store Core Book Details : Robert Scott, Jim Fitch, and Lloyd Leugner. : 220-page paperback published in 2012.

: Designed as a self-paced learning tool and a study aid for Level I lubrication certification Key Updates

: The 4th edition was restructured to focus on reliability and includes updated graphics, illustrations, and color tables to make complex concepts easier to implement. Noria Store Primary Topics Covered

The handbook addresses several critical areas of machinery maintenance, including: Lubricant Properties

: Detailed information on base oils, additives, and oil properties. Applications

: Guidance on grease applications, journal bearings, and compressors. Operational Control

: Best practices for contamination control, storage, and lubricant testing. Field Troubleshooting

: Includes four "hard-fast rules" for determining if after-market additives are appropriate for specific machinery. Noria Store Purchasing Information Availability & Notes Noria Store

Available as their all-time best-selling book; often used alongside their "Fundamentals of Machinery Lubrication" training. Lists the 2012 paperback edition with 220 pages.

Note: Be careful not to confuse this with "Practical Lubrication for Industrial Facilities" by Kenneth Bannister, which released its 4th edition in 2024 and is a significantly larger 790-page manual. Precision Lubrication Magazine , or do you need it for on-the-job troubleshooting

The Practical Handbook of Machinery Lubrication - 4th Edition

Overview

The handbook is designed for maintenance professionals, engineers, and anyone involved in the lubrication of industrial machinery. It covers a wide range of topics related to machinery lubrication, from basic principles to advanced techniques.

Key Features

1. Comprehensive Coverage: The handbook covers various aspects of machinery lubrication, including lubricant properties, lubrication systems, bearing types, and applications.
2. Updated Content: The 4th edition includes updated information on lubricant technology, new lubricant formulations, and recent developments in lubrication systems.
3. Practical Approach: The book focuses on practical applications and provides step-by-step guidelines for lubricant selection, lubrication system design, and maintenance.
4. Illustrations and Examples: The handbook includes numerous diagrams, charts, and photographs to illustrate key concepts and make the information more accessible.

Strengths

1. Authoritative Source: The handbook is written by experts in the field of machinery lubrication, ensuring that the information is accurate and reliable.
2. Wide Range of Topics: The book covers a broad spectrum of topics related to machinery lubrication, making it a valuable resource for professionals with varying levels of experience.
3. Easy to Understand: The writing style is clear, and the use of illustrations and examples makes the information easy to comprehend.

Weaknesses

1. Technical Level: The handbook assumes a basic understanding of machinery and lubrication principles, which may make it challenging for beginners to follow.
2. Limited Coverage of Specialized Topics: Some users have noted that the handbook could provide more in-depth information on specialized topics, such as lubrication in specific industries (e.g., aerospace or food processing).

Target Audience

The handbook is suitable for:

1. Maintenance professionals
2. Mechanical engineers
3. Lubrication specialists
4. Plant managers
5. Anyone involved in the lubrication of industrial machinery

Conclusion

"The Practical Handbook of Machinery Lubrication, 4th Edition" is a valuable resource for professionals seeking to improve their knowledge and skills in machinery lubrication. While it may have some limitations, the handbook's comprehensive coverage, practical approach, and authoritative authorship make it a reliable and useful guide for anyone involved in the lubrication of industrial machinery.

5. The Synergy Between Lubrication and Oil Analysis

Perhaps the most modern update in this edition is the integration of Oil Analysis into the daily workflow.

The book treats oil analysis not just as a lab report, but as a vital sign of machine health. It guides the reader on:

• Sampling techniques: How to get a representative sample (the "gold standard" of sampling ports).

The Practical Handbook of Machinery Lubrication (4th Edition)

is a comprehensive 220-page guide for reliability professionals focusing on modern lubricant application, contamination control, and machine maintenance strategies. Authored by experts at Noria, it covers the entire lubrication lifecycle, including troubleshooting, grease gun practices, and asset management in line with ISO standards. This heavily illustrated text also serves as a key resource for ICML certification preparation.

You can purchase the book from Noria Store or read a detailed overview of the book's contents in the article regarding the 4th Edition.

The Practical Handbook of Machinery Lubrication - 4th Edition

Title: The Bible Got an Upgrade: Why “The Practical Handbook of Machinery Lubrication, 4th Edition” is Non-Negotiable for Reliability Pros

If you work in maintenance, reliability, or asset management, you know the struggle. You’ve probably got a shelf (physical or digital) full of theoretical textbooks, complex OEM manuals, and outdated slides from a training seminar you took a decade ago. But there is one book that has likely earned a permanent, coffee-stained spot on your desk: The Practical Handbook of Machinery Lubrication. Title: The Bible Just Got Better: A First

For years, the 3rd Edition was the gold standard. It was the text that finally connected the dots between tribology, contamination control, and real-world machine uptime. Now, the team at Noria—specifically authors Jim Fitch and Troy Clark—has released the 4th Edition, and it is not just a refresh. It is a complete overhaul for the modern industrial era.

Here is why you need to stop what you are doing and get this version into your hands.

1. It Bridges the Gap Between “Old School” and “New School”

The fundamentals of viscosity and film strength haven’t changed, but how we monitor them has. The 4th Edition does a masterful job of honoring the legacy principles of lubrication (the “why”) while fully diving into the digital transformation of lubrication (the “how”).

• The Internet of Things (IoT) & Industry 4.0: The new edition dedicates significant real estate to connected sensors, online debris monitoring, and real-time oil condition analysis. It no longer treats automated lubrication as a luxury; it treats it as a standard practice.
• Data-Driven Decisions: It moves away from “change the oil every 3 months” to “change the oil when the data tells you to.” The statistical process control (SPC) sections have been updated to help you talk to your boss (or your accountant) using ROI metrics, not just anecdotes.

2. Contamination Control: Beyond the “Gut Feeling”

We all know that 80% of machine failures are fatigue-related, and 80% of those are driven by contamination. But knowing that and fixing that are two different things.

The 4th Edition gets ruthlessly practical. It doesn't just tell you that "clean oil is good." It provides updated nomographs and case studies showing the precise relationship between particle count, ISO codes, and bearing life.

• The New Target: While previous editions focused on getting "clean enough," this edition pushes the envelope on proactive cleanliness. It offers specific, actionable strategies for desiccant breathers, quick-connect fittings, and the latest in filter media technology.

3. The Lubricant Volume Handbook (Baked In)

One of the most tedious parts of the job is knowing how much grease to put in a bearing. Too little, you weld it. Too much, you cook it. The 4th Edition has expanded its reference charts and calculation methods dramatically.

If you are a field technician, the formulas and reference tables alone are worth the price of admission. You can finally stop guessing and start calculating based on bearing size, speed factor (NDm), and grease consistency (NLGI grade).

4. Solving the "Scheduled vs. Condition-Based" Debate

How do you handle a plant that runs 24/7? When do you take that critical pump offline if the oil looks fine but the ferrous density is spiking? Chapter 9 (Oil Analysis) and Chapter 12 (Problem Solving) in the 4th Edition read like a troubleshooting flow chart for your mind.

It includes updated logic trees for:

• High viscosity (Is it oxidation or the wrong top-off oil?)
• Water contamination (Free, emulsified, or dissolved? And how to fix each.)
• Varnish potential (The silent killer of turbines and hydraulics.)

5. It’s Actually Readable (Yes, Really)

Let’s be honest: Machinery lubrication texts are usually drier than a desert. This book isn't. The 4th Edition uses high-resolution color photography, better diagrams, and a layout that respects your attention span. It is designed for the person who is on their feet for 10 hours a day, not the PhD student in a quiet library.

Who absolutely needs this?

• The New Technician: If you are an apprentice or a multi-craft maintenance person who got handed a grease gun without training, this book is your career insurance.
• The Reliability Engineer: You need the updated math, the failure mode models, and the economic justifications to push back against "run-to-failure" management.
• The C-Suite (CFO/COO): You need to read the first three chapters. It explains, in plain English, why a $5,000 oil analysis lab and $500 in desiccant breathers saves you a $250,000 gearbox rebuild.
• The Veteran: You need it to stay current. The rules of the game have changed. IoT has arrived. Old habits (like relying on color and smell to judge oil) are dangerous habits. This book recalibrates your intuition.

The Verdict

If you only buy one technical manual this decade, make it The Practical Handbook of Machinery Lubrication, 4th Edition. It is the definitive text on keeping rotating assets rotating.

It moves you from a reactive "fix-it-when-it-breaks" culture to a proactive "lube-it-right-so-it-never-breaks" culture.

Don't just change the oil. Change your mind. Get the 4th Edition.

Have you read the 3rd edition? How are you handling the transition to automated lube systems in your plant? Drop your thoughts below.

The Practical Handbook of Machinery Lubrication, 4th Edition

(authored by Robert Scott, Jim Fitch, and Lloyd Leugner) is a

220-page comprehensive guide designed to improve machine reliability through best lubrication practices

. This edition was completely rewritten to focus on reliability-centered maintenance and includes updated graphics and illustrations. Machinery Lubrication Core Content & Chapter Topics

The handbook is structured into several key sections that address the "A to Z" of machinery lubrication: Noria Store Reliability and Maintenance Strategies:

Defining machine failure, maintenance philosophy, and the cost of reliability. Lubrication Fundamentals:

Surface interaction, lubrication regimes, and the science of tribology. Lubricant Properties and Selection: Oil Properties: Base oils, additives, and viscosity/viscosity index.

Grease thickeners, application methods, and regreasing frequency. Specialized Lubricants:

Food-grade, environmentally friendly, and metalworking fluids. Component-Specific Lubrication: Rolling-element and journal bearings. Industrial and automotive gear systems.

Reciprocating engine lubricants and API service classifications.

Hydraulics, compressors, steam/gas turbines, and machine tool way lubricants. Management & Troubleshooting: Contamination Control:

Management of solid, water, air, fuel, and soot contaminants. Storage and Handling:

Best practices for managing lubricant delivery and storage areas. Condition Monitoring: Oil sampling basics, testing methods, and oil analysis. Failure Analysis:

Troubleshooting wear and root cause failure analysis (RCFA). Noria Store Key Features of the 4th Edition Certification Alignment:

Designed as a primary study aid for ICML Level I and II certifications (MLA I, MLT I, and MLT II). Practical Focus: “The viscosity of oil changes roughly 5-7% for

Includes checklists, example calculations for relubrication intervals, and step-by-step procedures. Updated Graphics:

Features high-quality illustrations to help readers recognize root causes of failure. Noria Store This handbook is available for purchase at the Noria Store oil analysis test methods covered in this handbook?

The Practical Handbook of Machinery Lubrication - 4th Edition

Introduction

The Practical Handbook of Machinery Lubrication, 4th Edition, is a comprehensive guide to the principles and practices of machinery lubrication. Written by experts in the field, this handbook provides practical information on the selection, application, and maintenance of lubricants in various industrial settings. The handbook is designed to help maintenance professionals, engineers, and lubricant specialists optimize equipment performance, reduce downtime, and improve overall plant efficiency.

Key Features of the Handbook

The 4th edition of the handbook includes:

1. Updated information on lubricant technology: The handbook covers the latest developments in lubricant chemistry, including advances in synthetic lubricants, biodegradable lubricants, and lubricant additives.
2. Expanded coverage of lubrication applications: The handbook provides detailed information on lubrication applications for various industries, including power generation, oil and gas, chemical processing, and food processing.
3. New chapters on specialized topics: The handbook includes new chapters on topics such as lubrication of electric motors, lubrication of gearboxes, and lubrication of hydraulic systems.
4. Practical guidelines for lubricant selection: The handbook provides a step-by-step approach to selecting the right lubricant for a specific application, including guidelines for evaluating lubricant properties and performance characteristics.
5. Troubleshooting and maintenance tips: The handbook offers practical advice on troubleshooting common lubrication-related problems and performing routine maintenance tasks.

Chapter Outline

The handbook is organized into the following chapters:

1. Introduction to Machinery Lubrication: Overview of the importance of lubrication, lubricant types, and lubrication methods.
2. Lubricant Properties and Selection: Description of lubricant properties, such as viscosity, lubricity, and thermal stability, and guidelines for selecting the right lubricant for a specific application.
3. Lubrication Systems and Components: Overview of lubrication systems, including oil circulation systems, grease lubrication systems, and lubrication system components, such as pumps, filters, and valves.
4. Lubrication Applications: Detailed information on lubrication applications for various industries, including power generation, oil and gas, chemical processing, and food processing.
5. Specialized Lubrication Topics: New chapters on lubrication of electric motors, lubrication of gearboxes, and lubrication of hydraulic systems.
6. Troubleshooting and Maintenance: Practical advice on troubleshooting common lubrication-related problems and performing routine maintenance tasks.
7. Lubricant Analysis and Condition Monitoring: Description of lubricant analysis techniques, such as oil sampling and laboratory testing, and condition monitoring methods.

Key Takeaways

The Practical Handbook of Machinery Lubrication, 4th Edition, provides readers with:

1. Improved understanding of lubricant technology: Readers will gain a deeper understanding of lubricant chemistry and the properties of various lubricant types.
2. Practical guidelines for lubricant selection: Readers will learn how to select the right lubricant for a specific application and evaluate lubricant performance characteristics.
3. Enhanced troubleshooting and maintenance skills: Readers will gain practical advice on troubleshooting common lubrication-related problems and performing routine maintenance tasks.
4. Increased knowledge of specialized lubrication topics: Readers will learn about the latest developments in specialized lubrication topics, such as lubrication of electric motors and lubrication of hydraulic systems.

Target Audience

The Practical Handbook of Machinery Lubrication, 4th Edition, is designed for:

1. Maintenance professionals: Maintenance engineers, technicians, and mechanics who are responsible for maintaining and troubleshooting industrial equipment.
2. Lubricant specialists: Lubricant specialists who are responsible for selecting and specifying lubricants for industrial applications.
3. Engineers: Engineers who design and operate industrial equipment and need to understand the principles of machinery lubrication.
4. Plant managers: Plant managers and operations personnel who are responsible for optimizing plant efficiency and reducing downtime.

Conclusion

The Practical Handbook of Machinery Lubrication, 4th Edition, is a comprehensive guide to the principles and practices of machinery lubrication. With its updated information on lubricant technology, expanded coverage of lubrication applications, and practical guidelines for lubricant selection, this handbook is an essential resource for maintenance professionals, engineers, lubricant specialists, and plant managers.

The definitive guide to modern machinery lubrication is found in

The Practical Handbook of Machinery Lubrication, 4th Edition .

Whether you are a seasoned reliability engineer or a technician just entering the field, mastering industrial lubrication is one of the most effective ways to boost machine lifespan and reduce costly downtime.

Below is a scannable breakdown of why this specific industry handbook is widely considered an essential desk and field reference. 📘 Why This Book is a Best-Seller

Unbiased Expertise: Authored and published by industry authority Noria Corporation, maintaining strict vendor neutrality to focus purely on best practices rather than specific product brands.

Easy to Read: Complex chemical concepts and engineering principles of tribology are translated into clear, plain English that anyone can grasp.

Visual Learning: The 4th edition features completely restructured chapters and updated graphics to quickly illustrate how lubricants fail and how to protect your assets. 🛠️ Key Topics Covered in the 4th Edition

Lubricant Fundamentals: Understand exactly how lubricants work at a molecular level and what causes base oils to break down over time.

Contamination Control: Master the techniques needed to filter out particulates and moisture to prevent abrasive wear.

The Myth of Additives: Learn how aftermarket or supplemental additives can backfire by competing for metal surfaces or throwing the oil's chemical balance out of proportion.

Storage and Handling: Discover how world-class facilities design their lubrication rooms and transfer carts to stop contamination before the oil ever touches a machine.

Grease Gun Safety: Realize how a standard grease gun can become a lethal weapon to machine bearings if used by an untrained operator. 🎯 Who Benefits From This Handbook?

Maintenance Managers: Use the guidelines to establish structured, cost-saving lubrication routes and scheduling.

Reliability Engineers: Leverage the text's heavy focus on root cause failure mechanisms to prevent chronic machinery breakdowns.

Certification Candidates: This specific edition aligns directly with the core knowledge required for professionals studying to achieve high-level industrial machinery lubrication certifications.

Are you looking to train a team on these principles, or are you studying for an individual professional certification? OIL ANALYSIS LABS FOR AFRICA - WearCheck

The Practical Handbook of Machinery Lubrication (4th Edition) , published by Noria Corporation

, is a 220-page guide focused on reliability-centered maintenance and practical lubrication techniques

. Revised by Robert Scott, the text covers lubricant fundamentals, contamination control, and condition monitoring, aligning with ISO 55001 and ICML 55 standards to improve machinery reliability. For more information, visit Noria. Noria Corporation The Practical Handbook of Machinery Lubrication Available

Part IV: The Application of Lubricants

This is the "how-to" heart of the book. It provides torque values for grease fittings, calculations for oil mist systems, and diagrams for splash, forced-feed, and wick lubrication systems. Specifically, the 4th Edition adds a chapter on ultrasonic lubrication, teaching you how to use sound waves to stop greasing a bearing before you blow the seal—a radical shift from time-based to condition-based greasing.