Why Is Bearing Vibration Increasing? Causes and Testing Guide Malaysia
Meta Description: Learn why bearing vibration increases and how Malaysian factory teams can investigate bearing wear, imbalance, misalignment, looseness and lubrication problems.
A gradual increase in bearing vibration can provide early warning that a motor, pump, fan, compressor or gearbox is developing a problem.
However, high vibration near a bearing does not automatically mean the bearing itself is damaged.
The vibration may originate from imbalance, misalignment, looseness, resonance, the driven machine or changing operating conditions.
Maintenance teams should examine the complete machine before replacing the bearing.
Common Causes of Increasing Bearing Vibration
Possible causes include:
Bearing deterioration
Mechanical imbalance
Shaft misalignment
Loose mounting
Poor lubrication
Excessive lubrication
Incorrect belt tension
Coupling wear
Bent shaft
Damaged fan or impeller
Gearbox problems
Cavitation
Structural resonance
Changing machine speed or load
1. Bearing Deterioration
Bearings may deteriorate because of:
Normal wear
Contamination
Moisture
Incorrect installation
Excessive load
Electrical damage
Poor lubrication
Misalignment
High temperature
Possible signs include:
Increasing vibration
Abnormal noise
Higher bearing temperature
Lubricant discolouration
Excessive movement
Repeated bearing problems
A basic vibration meter detects changes in overall vibration but may not identify the exact internal bearing defect.
2. Mechanical Imbalance
Imbalance occurs when mass is distributed unevenly around a rotating component.
Possible sources include:
Dirty fan blades
Damaged impeller
Missing material
Product buildup
Uneven pulley
Damaged coupling
Incorrect repair work
Imbalance-related vibration often changes strongly with rotational speed.
Use a tachometer to record RPM together with the vibration reading.
3. Shaft Misalignment
Misalignment may occur between:
Motor and pump
Motor and gearbox
Gearbox and driven equipment
Coupled shafts
Possible signs include:
High axial vibration
Hot bearings
Coupling wear
Seal leakage
Repeated bearing replacement
Increased motor current
Replacing the bearing without correcting alignment may lead to another failure.
4. Mechanical Looseness
Loose components can amplify vibration.
Inspect:
Bearing-housing bolts
Motor feet
Pump feet
Baseplate
Anchor bolts
Guards
Covers
Structural supports
Coupling fasteners
A vibration problem may come from the mounting structure rather than the rotating component.
5. Lubrication Problems
Both insufficient and excessive lubrication can affect bearing condition.
Insufficient Lubrication
May increase friction, temperature, noise and wear.
Excessive Lubrication
Can cause churning, heat and seal damage.
Incorrect Lubricant
May not provide the required viscosity or protection.
Record lubricant type, quantity and application date.
6. Incorrect Belt Tension
Excessive belt tension increases radial load on motor and fan bearings.
Insufficient tension can cause:
Slippage
Heat
Belt dust
Speed variation
Noise
Measure both driving and driven speeds where appropriate.
7. Coupling Problems
A damaged or incorrectly installed coupling may create:
Misalignment
Looseness
Impact
Axial vibration
Uneven torque transmission
Inspect the coupling only after the machine is correctly isolated.
8. Bent Shaft
A bent shaft may cause cyclic movement and vibration.
Possible indications include:
Repeated alignment difficulty
Shaft runout
Uneven seal wear
Axial vibration
Repeated bearing problems
More detailed mechanical measurement may be required to confirm shaft condition.
9. Pump Cavitation
A pump experiencing cavitation may produce:
Crackling or gravel-like noise
Unstable vibration
Reduced flow
Fluctuating pressure
Impeller damage
Investigate:
Suction restriction
Low liquid level
High fluid temperature
Blocked strainers
Air entering the system
Incorrect pump operating point
Cavitation should not be diagnosed from bearing vibration alone.
10. Fan Blade Problems
Fan vibration may increase because of:
Dust buildup
Bent blades
Corrosion
Cracks
Missing material
Incorrect blade angle
Loose blade attachment
Inspect the complete fan assembly after safe isolation.
11. Gearbox Problems
Gear or gearbox-bearing issues may transmit vibration into nearby bearing housings.
Check:
Input-side vibration
Output-side vibration
Gearbox temperature
Lubricant condition
Noise
Motor current
Equipment load
The highest reading may not always be located at the original vibration source.
12. Structural Resonance
A machine can vibrate strongly when operating speed excites a natural frequency of the structure.
Possible signs include:
Vibration changes dramatically with small speed changes
One direction has much higher vibration
Nearby structural components vibrate
The machine becomes smoother outside a specific speed range
A simple vibration meter can identify the change, but more advanced analysis may be required to confirm resonance.
Check Measurement Conditions First
Before diagnosing the machine, confirm:
Same measurement point
Same direction
Same sensor mounting
Same machine speed
Similar load
Similar process condition
Same instrument setting
No nearby equipment change
A different measurement position can produce a different reading even when machine condition has not changed.
Where Should Vibration Be Measured?
Common bearing measurement directions are:
Horizontal
Vertical
Axial
Possible locations include:
Motor drive-end bearing
Motor non-drive-end bearing
Pump bearings
Fan bearings
Gearbox input bearing
Gearbox output bearing
Mark or photograph each measurement point for future inspections.
Useful Supporting Measurements
Temperature
Use an infrared thermometer or thermal camera to identify abnormal bearing heat.
Rotational Speed
Use a tachometer to confirm that readings are taken at comparable RPM.
Motor Current
Use a clamp meter to check whether the machine load has changed.
Noise
Use a sound level meter to document changes in overall equipment noise.
Process Information
Record pressure, flow, product load or damper position where relevant.
Basic Bearing Vibration Investigation
Step 1: Confirm the Reading
Repeat the measurement at the same point and direction.
Step 2: Check Machine Speed
Record RPM using a tachometer.
Step 3: Measure All Relevant Bearings
Compare the motor, driven equipment and gearbox.
Step 4: Measure in Three Directions
Record horizontal, vertical and axial vibration.
Step 5: Check Temperature
Compare bearing temperatures under the same operating condition.
Step 6: Inspect Mounting
Look for loose bolts, cracked supports and structural movement.
Step 7: Check Lubrication
Confirm the correct lubricant, quantity and interval.
Step 8: Inspect the Driven Equipment
Check the pump, fan, gearbox, conveyor or compressor.
Step 9: Compare the Trend
Review whether vibration increased gradually or suddenly.
Sudden vs Gradual Vibration Increase
Sudden Increase
Possible causes include:
Loose component
Broken fan blade
Product buildup
Coupling damage
Process change
Incorrect maintenance work
Mechanical impact
Gradual Increase
Possible causes include:
Bearing deterioration
Progressive misalignment
Lubrication problem
Gear wear
Corrosion
Increasing looseness
The pattern helps determine the direction of investigation.
Vibration Meter Options
MTM Precision supplies vibration meters including:
Landtek VM-6310
Landtek VM-6360
Smart Sensor AR63B
Benetech GM63B
Wintact WT63A
Wintact WT63B
A basic portable vibration meter is suitable for routine checks and trending.
More detailed fault diagnosis may require advanced vibration-analysis equipment and specialist interpretation.
Common Bearing Vibration Troubleshooting Mistakes
Avoid:
Replacing the bearing immediately
Measuring at different points each time
Ignoring machine speed
Ignoring process load
Measuring only one bearing
Ignoring axial vibration
Adding excessive lubricant
Failing to inspect mounting bolts
Assuming all pump vibration is cavitation
Ignoring the motor and driven equipment
Comparing different machines without context
Continuing operation after a severe or sudden change
Bearing Vibration Testing Tools Supplier in Malaysia
MTM Precision supplies instruments for investigating bearing vibration, motor condition, pump problems, fan imbalance, gearbox wear and rotating machinery faults.
Our range includes vibration meters, tachometers, thermal imaging cameras, infrared thermometers, clamp meters and sound level meters.
Contact MTM Precision
MTM Precision Sdn. Bhd.
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
🌐 Website: www.mtmpre.com.my
📧 Email: mtmpre@yahoo.com
📱 WhatsApp: +6016-660 7346
31 Aug 2026
