Whether you heard it on a Bellingham commute or a trip from elsewhere in Whatcom County, a short description of what you already noticed can help. You do not need to make another trip to reproduce the noise.
When to stop gathering observations
If the noise comes with new vibration, a change in steering or braking, or suspected tire damage, reduce speed carefully and stop in a safe place. Michelin tire guidance calls for a safe stop when vibration or other disturbances appear. Seek guidance or roadside assistance before continuing if the vehicle may be unsafe. Do not drive farther to complete a symptom diary.
Why tire and wheel bearing noises can be hard to distinguish
Uneven or irregular tire wear can create noise; Michelin recommends inspection for noisy tires. A wheel bearing can also produce a hum or rumble. Timken light vehicle guidance describes overlapping noise terms associated with tires and drivetrain components, including bearings. Calling a sound a hum does not separate those possible sources.
Road surface, tire tread design and wear patterns can all affect the noise being investigated. Professional wheel and hub inspection guidance considers those factors along with alignment and suspension condition. Tire replacement, rotation, alignment, previous repairs and impacts are useful history because they help establish what changed; recent work is not proof of a cause.
An appropriate investigation may include inspecting tires for irregular wear or damage and checking the wheel and hub assembly for roughness, looseness or noise. The checks and any further work must follow the instructions for the exact Subaru. The sound description alone, or where it seems loudest in the cabin, is not enough to select a replacement part.
What the Subaru bulletins establish
Subaru bulletin 03-96-25, dated April 22, 2025, discusses rear-hub design changes and humming or grinding complaints in specified applications. Its listed coverage includes 2019-2024 Forester and 2024 Crosstrek models. It calls for a confirmed rear-hub finding before applying its repair information.
A separate Subaru bulletin 05-70-19R, revised December 2, 2020, describes a rear backing-plate condition that can affect the hub and bearing and produce howling. Its listed applications are 2014-2018 Forester, 2012-2019 Impreza and 2013-2019 Crosstrek.
These are limited technical examples. They do not establish how common a concern is or diagnose your vehicle. Their coverage must not be extended to unlisted models or years.
Describe what you already noticed
Tell us the approximate speed range, sound and conditions you remember from ordinary travel. If you already noticed a difference between road surfaces, acceleration, normal turns or braking, include it without treating it as proof of a failed part.
Do not weave, make repeated turns, coast in neutral or drive specifically to test the noise. Do not handle a phone or write notes while driving. Complete the diary when safely parked and leave unknown details blank.
A practical symptom diary
Copy these prompts and add brief notes from memory. Approximate information is useful when identified as approximate.
| Observation | Your notes from what you already noticed |
|---|---|
| Vehicle year and model, engine and transmission if known, approximate mileage | |
| When the noise started and whether it seemed sudden or gradual | |
| Approximate speed range already noticed during ordinary travel | |
| Sound description and where it seemed loudest, if you could tell | |
| Road surface, weather and other conditions already observed | |
| Other symptoms such as vibration, pulling, warnings or braking changes | |
| Recent tire work, repairs or impacts, without assuming a connection | |
| Existing service records or recordings obtained safely |
An existing recording may help us recognize the concern, but it does not replace inspection. Do not make another trip to capture one or keep driving to fill gaps in the diary.
How an investigation leads to a repair plan
Our Subaru investigation process starts with the concern and vehicle history. If further investigation is needed, we explain the proposed work, quote an initial amount of investigation time and obtain your approval before proceeding.
We explain what the findings support and what remains uncertain. When enough information is available, those findings help us develop a repair plan and estimate for your approval. If additional investigation time is needed, we explain why and obtain approval first. Approval to investigate does not commit you to a particular repair.
For background on tire matching and drivetrain care, see our Subaru AWD and differential guide. For the work that may follow an investigation, explore our Subaru repair services.
Arrange a Subaru noise investigation in Bellingham
Call 360-325-7824 with your Subaru's year, model, approximate mileage and what you heard. For planned service, you can request a service visit. We will contact you to discuss the next step; submitting the form does not confirm an appointment.
Subi-R-Us is at 3815 Bakerview Spur #6B, Bellingham, WA 98226, serving Subaru owners from Bellingham and Whatcom County. You can call or text 360-325-7824; staff respond to texts during regular business hours. If the vehicle may be unsafe, call from a safe place before bringing it to the shop.
Sources and Further Reading
- Subaru bulletin 03-96-25 - Rear Axle Hub Design Change (April 22, 2025)
- Subaru bulletin 05-70-19R - Rear Wheel Backing Plate Design Change (revised December 2, 2020)
- Michelin tire FAQ - noise and irregular wear
- Michelin worn-tire guidance - vibration and safe stopping
- Timken Light Vehicle TechTips LV5 - symptoms of a worn wheel hub bearing
- Timken Light Vehicle TechTips LV3 - checking a hub bearing assembly