Quick Replacement Procedure for Sliding Bearings During Emergency Equipment Shutdowns

Equipment downtime is the single most costly event in industrial operations. When a sliding bearing fails unexpectedly, every minute of shutdown translates into lost production, delayed deliveries, and mounting financial losses. In sectors like mining, steel production, wind energy, and heavy manufacturing, an unplanned stop can cost tens of thousands of dollars per hour.

Having a quick, systematic replacement procedure for sliding bearings during emergency shutdowns is not just good maintenance practice—it is a competitive necessity. When the main bearing fails, the component must be replaced or repaired swiftly and correctly to minimize production losses. However, the cost of bearing replacement is often compounded by the difficulty of accessing the bearing and the risk of secondary damage from contamination during the repair.

This guide provides a practical, step-by-step emergency replacement procedure for sliding bearings, covering rapid assessment, tool preparation, safe removal, installation checks, and restart protocols. For engineers and maintenance teams sourcing high-quality sliding bearings from CNEPEN, this procedure ensures that replacement components are installed correctly and return to service with minimal delay.

Part 1: Pre-Replacement Rapid Assessment

Before beginning any physical work, a quick but thorough assessment determines whether replacement is the correct course of action and identifies potential complications.

1.1 Is Replacement Necessary?

Not every bearing failure requires immediate replacement. Sometimes, a temporary repair or lubrication restoration can get the equipment running while a replacement is ordered.

Indicators that replacement is required:

• Visible scoring or galling on the sliding surface
• Bearing temperature exceeding 100°C (thermal runaway)
• Abnormal noise (grinding, squealing, or knocking)
• Excessive shaft play or vibration
• Lubricant contamination with metal particles (indicating wear debris)

Temporary measures (only if safe and approved by engineering):

For minor surface damage, a field-replaceable liner can be exchanged without removing the entire bearing assembly. In some designs, the bearing liner can be rolled up, detached from the locating spigot, pushed out, and a new liner inserted in under 40 seconds.

For wind turbine bearings, some designs allow replacement of bearing pads without removing the entire bearing shell, significantly reducing service time and cost. A carrier body stays in place while only the liner is exchanged.

1.2 Identify Bearing Type and Specifications

Before initiating a replacement, confirm the exact specification of the failed bearing. Installing an incorrect bearing—even as an emergency substitute—can lead to catastrophic failure shortly after restart.

Information Required	How to Obtain
Part number	Bearing housing marking, maintenance records
Dimensions (ID, OD, length)	Measure old bearing (if intact), refer to equipment manual
Material type	PTFE composite, POM composite, bronze, bi-metal
Load rating	Equipment specification
Tolerance class	H7/h7 typical for automotive/industrial applications

Critical note: If a substitute bearing is used as an emergency measure to get a machine back into production quickly, the substitution must be entered into the historical records for that machine. This documents the temporary change and avoids the possibility of the substitute becoming a permanent replacement—an error that can be extremely costly if an incorrectly specified bearing continually fails prematurely.

1.3 Gather Required Tools and Equipment

Having the right tools on hand before starting the replacement is essential for a quick turnaround. Typical requirements:

Standard tools:

• Wrenches and sockets for housing bolts
• Puller or press for bearing removal
• Clean rags and lint-free cloths
• Measuring tools (micrometer, caliper, feeler gauges)
• Lubricant (specified grease or oil for the bearing type)
• Torque wrench (for housing bolts)

For split sliding bearings (bearing bushes):

• Wooden hammer or wooden pad (do not strike the bearing bush directly with a hand hammer)
• Triangular scraper or old piston ring for scraping (if fitting required)

For heavy equipment or bridge bearings:

• Jacking system (hydraulic jacks, cribbing)
• Lifting device (if the superstructure must be raised to access bearings)
• Transportation brackets to hold the bearing during removal

Part 2: Safe Removal of the Failed Bearing

2.1 Prepare the Work Area

Safety is paramount during emergency maintenance.

Before starting:

• Lock out/tag out (LOTO) the equipment
• Allow the bearing to cool (if overheated)
• Clean the surrounding area to prevent contamination
• Cover openings to prevent debris entry

2.2 Access the Bearing

Many sliding bearings are located in difficult-to-access positions (wind turbine drive trains, bridge supports, conveyor systems). This often requires special procedures:

For bridge bearings (structural applications):

• Develop a jacking plan (performed by a licensed engineer)
• Install traffic control devices if necessary
• Jack the existing superstructure as directed by a licensed engineer
• Remove the existing bearings and clean debris from the substrate
• Repair the bridge seat as needed

For heavy machinery (crushers, mills):

• Remove guards and covers
• Disconnect lubrication lines (if present)
• Loosen housing bolts (use torque wrench to document removal torque)

2.3 Remove the Failed Bearing

The removal method depends on bearing type:

For split sliding bearings (bearing shells):

• Place the bearing correctly when pressing it out—force must be uniform to prevent bias
• Use a wooden hammer or wooden pad to tap the bearing out
• Do not strike the bearing directly with a hand hammer
• Remove both upper and lower shells; check for debris in the housing

For pressed-in bushings:

• Use a suitable puller or press
• Apply force only to the ring with the interference fit
• If the bushing is stuck, apply penetrating oil and allow it to soak

For PTFE/composite liners (replaceable liners):

• Push the linear plain bearing off the shaft
• Slightly roll the liner up and detach it from the locating spigot and anti-rotation element
• Push the liner out of the housing

Critical safety note: In wind turbine applications, bearing exchange is very complicated and costly, especially offshore. Some designs allow bearing pad exchange without removing the bearing shell—significantly reducing service time and costs. The bearing pads may be replaced by removing an opening in the bearing shell, allowing access to the bearing pads.

2.4 Inspect the Housing and Shaft

Before installing the new bearing, inspect the housing bore and shaft:

Inspection Item	What to Look For	Action
Housing bore	Scoring, burrs, distortion	Deburr, clean; if damaged, consult engineering
Shaft surface	Scoring, wear, out-of-round	Polish if minor; if major, shaft must be replaced or repaired
Lubrication passages	Blockages, contamination	Clean with compressed air or solvent
Locating features	Damage to pins, keys, or lugs	Repair or replace as needed

If debris or foreign particles are present, the bearing must be cleaned after machining to remove loose particles and dust. Oil can be used as a liquid to flush the bearing and remove loose particles and dust, preventing damage to the sliding surface.

Part 3: Installation of the Replacement Bearing

3.1 Prepare the New Bearing

CNEPEN's sliding bearings are manufactured to tight tolerances and require specific handling to preserve their integrity.

Before installation:

• Remove the new bearing from its protective packaging only at the installation point
• Inspect for damage (scratches, deformation, contamination)
• Verify dimensions match the failed bearing
• If the bearing requires lubrication, apply the specified grease or oil

3.2 Install the Bearing

For split sliding bearings:

The distance across the outside parting edges of a plain bearing are manufactured slightly greater than the housing bore diameter. During installation, a light force is necessary to snap it into place. This "crush" sets up a high radial contact pressure between the bearing and housing, ensuring good back contact for heat conduction and preventing spinning.

Under no circumstances should the bearing parting lines be filed or otherwise altered to remove the crush.

Align oil grooves and oil holes with the housing's oil passages.

Do not pad between the bearing outer surface and the housing with paper or copper to adjust clearance. Adding pads cannot accurately ensure clearance and will damage heat transfer, shortening service life.

For pressed-in bushings:

• Apply a light coating of oil to the housing bore and bearing OD
• Press the bearing using a suitable tool, ensuring square alignment
• Press until the bearing is fully seated against the housing shoulder

For PTFE/composite liners:

• Insert the new liner (slightly overlapping) into the housing
• Allow it to latch into place on the locating spigot
• Ensure the anti-rotation element is engaged

For bridge bearings (structural):

• Place the new bearing in the correct location
• Fix the lower pins to the anchoring dowels
• Lower the superstructure onto the bearing
• Remove transportation brackets

3.3 Check and Set Clearance

Proper clearance is essential for lubrication film formation. Insufficient clearance prevents oil entry, leading to semi-dry friction, overheating, and bush burning. Excessive clearance allows oil to escape quickly, preventing film maintenance.

For split bearings requiring scraping:

• Install the bearing with bolts torqued to specification
• Rotate the shaft several times
• Remove the bearing and inspect wear marks on the bearing surface
• Scrape marks with a triangular scraper or old piston ring
• Repeat until contact area is adequate and traces are evenly distributed

General clearance guidelines:

• Top clearance: approximately 1.5–2.0 thousandths of the shaft diameter
• Side clearance: approximately half the top clearance value

For pre-lubricated bearings like CNEPEN's self-lubricating bushings, initial pre-lubrication at assembly is necessary for optimal performance. For the low-maintenance EX Series, stamped lubrication indents are filled with grease during assembly and gradually released during operation.

3.4 Torque Housing Bolts

Tighten housing bolts in a crisscross pattern to ensure even loading. Use a torque wrench and follow the equipment manufacturer's specifications. If no specification is available, use standard bolt torque tables for the bolt grade and size.

Part 4: Post-Installation Verification

4.1 Visual and Dimensional Checks

After installation:

• Rotate the shaft by hand (where possible) to check for binding
• Verify the bearing is seated correctly in the housing
• Check that locating features (pins, keys) are engaged
• Confirm lubrication passages are aligned

4.2 Lubrication Check

For pre-lubricated bearings: Ensure the bearing has received its initial grease or oil charge.

For oil-lubricated systems:

• Verify oil level in the reservoir
• Check oil pressure (where applicable)
• Run the lubrication system for a few minutes before starting equipment

For grease-lubricated bearings: Apply grease at the specified intervals, filling only 1/3 to 1/2 of the housing cavity to avoid churning and overheating.

4.3 Documentation and Records

As noted earlier, any emergency substitution must be documented. Record:

• Date and time of replacement
• Bearing part number and batch code (from CNEPEN's traceability system)
• Reason for failure (if known)
• Tools and methods used
• Person performing the replacement
• This documentation ensures traceability and helps prevent future failures by identifying patterns.

Part 5: Restart and Monitoring

5.1 Controlled Start-Up

Run-in period: Run the equipment at 50–60% of normal speed with no load for 2–4 hours to allow micro-asperities to wear smoothly.

For split bearings: During the run-in, check for:

• Unusual noise
• Temperature rise (should be gradual, not sudden)
• Lubricant leakage

5.2 Temperature Monitoring

• Normal operating temperature: Typically 60–80°C depending on application
• Warning threshold: 20°C above normal
• Danger threshold: Exceeding 100°C (for Babbitt linings) indicates imminent failure

Install a high-temperature shutdown switch if not already present. If the bearing smokes or discolors, stop immediately.

5.3 Post-Start Inspection

• After 2–4 hours of operation under load, perform a final inspection:
• Check for abnormal noise or vibration
• Verify bearing temperature is stable
• Inspect for lubricant leaks
• Torque check housing bolts (if specified)

Conclusion

When emergency sliding bearing repairs need to be done quickly and accurately, they put the maintenance team's skills to the test. The steps listed above provide a structured framework that cuts down on downtime and guarantees quality installation. Getting the right tools, keeping enough extra parts on hand, and using predictive maintenance programs can greatly lower the number of times that an emergency stop has to happen. In the end, the dependability of equipment rests on choosing bearings that are right for the job and keeping them in good shape in a way that makes them last longer.

About CNEPEN (Jiashan EPEN Bearing Co., Ltd.)

CNEPEN is a professional Chinese manufacturer of plain bearings and sliding bearings, serving industrial customers worldwide.

Certifications: IATF 16949, ISO 9001, ISO 14001, ISO 45001

Primary Product Lines:

• Self-lubricating bushings (EU Series) – PTFE-based, maintenance-free
• Low-maintenance bushings (EX Series) – POM-based with lubrication indents
• Bronze wrapped bushings (E90/E92/E93/E94) – CuSn8/CuSn6 alloy
• Bi-metal bearings (EMT Series) – Steel-backed with alloy lining
• Custom sliding bearings – Tailored to specific applications

FAQ

How long does emergency bearing replacement typically take?

Replacement times vary a lot depending on the size and usability of the equipment. Small conveyor bearings might only take two to three hours to replace, which includes testing and safety processes. Large backhoe boom bearings, on the other hand, can take eight to twelve hours to replace completely. The level of preparation has a big effect on how quickly things get done.

What tools are essential for field bearing replacement?

The main set of tools includes hydraulic bearing pullers, precision measuring tools like micrometers and number indicators, torque wrenches with the right range, and hot equipment for interference fits. For specialized tasks, you might need extra tools that are designed to work with that equipment.

Can damaged shafts be repaired during bearing replacement?

During the replacement process, an emery cloth can often be used to clean away minor shaft damage like light cutting. For major wear patterns, deep gouges, or loss of volume, the shaft usually needs to be replaced or fixed by a professional using metalizing or chrome plating restoration methods.

Partner with Epen for Reliable Sliding Bearing Solutions

Maintenance teams that have done this before know that the quality of the bearings affects how quickly the equipment can be put back into use after an accident. Epen makes high-performance sliding bearing parts that are designed to work in heavy-duty devices like building gear, mining equipment, and industrial automation systems. Our bimetal and metal-plastic hybrid bearings can hold a lot of weight and have longer service intervals that cut down on the number of times they need to be serviced. In addition to keeping a large collection of standard catalog sizes, we also offer custom making for unique uses that need non-standard sizes or material requirements. Maintenance managers looking for a reliable sliding bearing provider can email our technical team at epen@cnepen.cn to talk about their unique needs and our ability to help with emergency replacements. Our engineering knowledge helps procurement teams choose the best bearing options that meet performance needs and can be quickly replaced in case of an unexpected shutdown.

References

Khonsari, M.M. and Booser, E.R., "Applied Tribology: Bearing Design and Lubrication," Third Edition, John Wiley & Sons, 2017.

Budynas, R.G. and Nisbett, J.K., "Shigley's Mechanical Engineering Design," Eleventh Edition, McGraw-Hill Education, 2020.

Neale, M.J., "The Tribology Handbook," Second Edition, Butterworth-Heinemann, 2001.

Harris, T.A. and Kotzalas, M.N., "Rolling Bearing Analysis: Essential Concepts of Bearing Technology," Fifth Edition, CRC Press, 2006.

Hamrock, B.J., stone, S.R., and Jacobson, B.O., "Fundamentals of Fluid Film Lubrication," Second Edition, Marcel Dekker, 2004.

Bloch, H.P. and Geitner, F.K., "Machinery Failure Analysis and Troubleshooting," Fourth Edition, Butterworth-Heinemann, 2012.