Find a sound
Contact listening at fixed machine points.
Stethoscope reference →Independent technical reference
Bearing inspection checklist: record, measure and assess reuse
Inspect the bearing together with its seats, lubricant and operating history. A smooth hand rotation is useful information but cannot certify remaining fatigue life. Compare findings with the manufacturer's acceptance criteria for the exact bearing and application.
On this page7 sections ⌄
Which bearing tester answers your question?
A “bearing tester” can mean several different tools. Use this reference to match an inspection task to its signal, compare documented instrument examples and understand what a reading cannot prove. This is a technical reference, not a shop or a pass/fail diagnostic service.
Track a change
Repeatable vibration and temperature measurements.
Vibration reference →Guide re-greasing
Ultrasonic feedback during an approved lubrication task.
Ultrasound reference →Localise vehicle noise
Compare sensor locations without assuming every noise is a hub.
Vehicle reference →4 documented instrument examples. Specifications are tied to the source editions below.
SKF
TMST 3
Electronic stethoscopeUse it to
Compare the sound at accessible, fixed machine locations.
Read / hear
Amplified contact sound
Do not infer
Listening helps locate a noise; it does not measure internal clearance, certify remaining life or give a calibrated vibration-severity value.
Documented specifications & source
- Frequency range
- 30 Hz–15 kHz
- Recorder output
- 250 mV maximum (audio)
SKF MP5336, September 2006, pp. 3–6. Archived instrument reference; accessory versions can differ.
SKF
QuickCollect CMDT 392
Portable vibration and temperature sensorUse it to
Record repeatable machine measurements and compare trends through a compatible SKF app.
Read / hear
Velocity, enveloped acceleration and surface temperature
Do not infer
The sensor, mounting point and settings affect readings. An overall value is not a confirmed bearing fault. CMDT 392-Ex has separate hazardous-area conditions; ordinary CMDT 392 is not an Ex substitute.
Documented specifications & source
- Bearing-related signal
- Enveloped acceleration, Band 3
- Temperature mode
- Infrared; unavailable with external sensor cable
- External sensor input
- 100 mV/g, two-wire constant-current accelerometer
- Sensor consistency
- Keep the same internal or external sensor for each trend
SKF XN-CMDT 392-02, Revision C, May 2026, pp. 10–13 and 18–19. The document revision, not its download filename, identifies this reference.
SKF
TLGU 10
Ultrasound lubrication checkerUse it to
Support controlled manual re-lubrication of a bearing designed and approved to be re-greased.
Read / hear
Ultrasonic signal level with audio feedback
Do not infer
An ultrasonic level is not a grease mass, an airborne sound-pressure reading or a universal damage score. Do not open sealed-for-life bearings just to use this technique.
Documented specifications & source
- Measurement bandwidth
- 35–42 kHz
- Displayed measurement range
- −6 to 99.9 dBµV
- Reference for displayed dB
- 0 dB = 1 µV
- Display resolution
- 0.1 dB
SKF 19018 EN, November 2020, pp. 1–2. This is the lubrication checker, not a leak detector or ultrasonic cleaning bath.
STEELMAN
ChassisEAR 06600
Multi-position vehicle noise locatorUse it to
Compare corresponding vehicle locations during an authorised diagnostic test, including wheel-bearing and alternative noise sources.
Read / hear
Selected microphone audio
Do not infer
The loudest channel is evidence to investigate, not proof a hub must be replaced. The driver must not operate this interface or wear the diagnostic headphones; the listening technician belongs in the passenger seat.
Documented specifications & source
- Microphone positions
- Up to 6 connected clamps
- Selection
- Listen to the chosen channel; not six simultaneous spectra
- Lead length
- 16 ft per microphone lead
- Location record
- Match each channel colour/number to its actual position
STEELMAN 06600 product specification and operating manual, revision 05/03/11, pp. 1–3.
No reference matches both filters. Clear the filters to see the four documented examples. A missing result does not mean that no suitable instrument exists.
What does the readout mean?
Audio / listening
A listening comparison locates a change in sound. Record the contact point, channel and gain. Louder playback is not a calibrated bearing-damage measurement.
Vibration velocity
Keep the unit, RMS/peak convention and frequency band with the value. Compare like-for-like measurements at the same operating condition; do not paste a universal alarm limit onto every machine.
Enveloped acceleration
Envelope processing emphasises repetitive impacts. Preserve the instrument’s band and processing settings. A value or peak still needs speed, bearing geometry and competing-source checks.
Ultrasonic dBµV
For the TLGU 10 reference, the dB scale is referenced to 1 µV. It is not dB sound pressure and cannot be directly compared with mm/s or another instrument’s unspecified dB scale.
Surface temperature
Keep location, load and ambient conditions. Infrared measurements depend on the surface and measurement arrangement; a housing surface is not the internal rolling-contact temperature.
These are interpretation checks, not unit-conversion formulas. No common damage score is calculated between audio, velocity, acceleration, ultrasound and temperature.
A useful trend needs a repeatable measurement
- Keep identityAsset, bearing position, instrument model, calibration status and sensor ID.
- Keep conditionsLocation, mounting, speed, load, temperature, units, band and gain.
- Keep the evidenceRetain raw observations and the reason for a follow-up check. A new sensor or setting starts a documented comparison, not an invisible change.
Use the existing diagnostic workbench to organise the investigation, or inspect the vibration evidence guide. Do not replace a test method with a calculator’s predicted defect frequency.
Similar names, different tests
Factory noise-testing machines
Bench acceptance testing is not the same task as listening to an installed machine. A valid result needs a defined fixture, speed, load, measurement method and product-specific acceptance limits. This reference does not supply a bench specification or factory pass/fail limits.
ABS / encoder-bearing testers
Checking an encoder or wheel-speed signal does not measure raceway condition. A magnetic viewing card also differs from an electronic sensor test. Start with encoder identification; vehicle-specific electrical testing remains separate.
Ultrasonic cleaning and leak detection
A cleaning bath is a treatment process, not a condition reading. An airborne leak detector is not automatically a contact-bearing lubrication checker. Match the instrument’s specified sensor and task, not the word “ultrasonic”.
Cleaning scope and limits →Looking for a Timken Bearing Tester?
Timken’s 2020 Engineering Manual, order 10668, printed p. 133, describes a handheld Bearing Tester for periodic condition and lubrication checks. The same page describes StatusCheck as a separate wireless temperature/vibration system, with two-axis vibration sensing and magnetic or threaded mounting.
These are historical catalogue descriptions, not verified current product availability. Exact tester part number, operating limits, calibration and a complete operating manual have not been verified here. Do not transfer the SKF specifications above to the Timken tester.
How this reference was checked
Reviewed 4 October 2026 against manufacturer documents. Specifications remain attached to their named editions; older instrument entries are reference examples, not purchasing recommendations. Device photos, manufacturer diagrams and marketing copy have not been republished. Source addresses, cached files and checksums remain in the private audit.
The model finder runs on the already-loaded reference data. It makes no database search or network request when you change a filter. Without JavaScript all four references and all five readout explanations remain available. Use browser printing for the complete reference.
What the evidence can — and cannot — tell you
| Observation or context | Interpretation to consider | Verification needed |
|---|---|---|
| Before cleaning | Condition and evidence | Photograph surfaces, marking, orientation, seals and lubricant condition. |
| After controlled cleaning | Surfaces and components | Inspect raceways, rolling elements, cages and rings under appropriate lighting. |
| Dimensional assessment | Measured condition | Use specified measuring methods for fits, clearance and accuracy. |
Plan the work safely
Identify and record
Assign an inspection identifier and record brand, full designation, machine position and operating history. Keep each bearing and its components together.
Check the context
Record observed cracks, chips, flaking, corrosion, wear and cage or seal damage without assigning an unsupported cause.
Verify before acting
Measure relevant seats and clearances with calibrated instruments. Note temperature, measurement direction and whether the bearing is mounted.
Keep the decision traceable
Apply the documented reuse or rejection criteria and retain the decision basis. Escalate critical, uncertain or damaged parts to qualified inspection rather than guessing.
Capture the information a model search cannot guess
Keep this checklist with your inspection or comparison. Checking a box only records that you have collected the item; it does not certify the bearing.
0 of 4 information groups recorded.
Technical basis & editorial scope
Original BearingScope workflow, written for catalogue research and comparison. Manufacturer material is used to check principles, not copied as a product endorsement or substituted for model-specific instructions. Reviewed 1 October 2026.
- JTEKT Basic Bearing Knowledge — Maintenance and inspection — Inspection, cleaning and reuse assessment
Source addresses and collection status are retained in the internal audit. No unpublished dimensions, torque settings, service intervals or interchange approvals are inferred.