Mazda Mazda3: BK Front Strut Top Mount Bearing Wear and Clunking
BK Front Strut Top Mount Bearing Wear and Clunking is a common suspension fault on the Mazda Mazda3 on the 2003–2009 cars, and we rate it major. Putting it right costs $280 to $700 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 37 documented faults on the Mazda Mazda3.
- Vehicle
- Mazda Mazda3
- Years
- 2003–2009
- System
- Suspension
What you are looking at
No photograph available
What goes wrong
The upper strut bearing plate on BK-generation Mazda3 deteriorates from water ingress into the unsealed bearing housing, allowing the thrust bearing races to develop corrosion pitting and flat spots. As the bearing loses its ability to rotate freely, the strut binds during steering lock changes and then releases suddenly, transmitting a sharp clunk or knock through the strut tower into the cabin, most pronounced at low speed when parking or traversing sharp dips.
What you would notice
- Sharp clunk or knock from front suspension when turning the steering wheel at low speed
- Clunking noise when the vehicle traverses speed bumps or sharp dips
- Steering feels notchy or requires extra effort when turning from lock during parking
How to check it
Where to look. Front strut top mount bearing plate beneath the engine bay strut towers, both sides
With the vehicle stationary on level ground, have an assistant turn the steering wheel lock to lock slowly while listening at each front strut tower for clunking. Compress the front suspension by pushing down on the bonnet and release to reproduce binding. With the front wheels raised, check for roughness and stiction in the strut bearing by rotating the hub assembly. Inspect the rubber upper mount isolator for cracking and separation.
What it costs to put right
$280 to $700 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Has the front suspension made any clunking or knocking noises?”
- “Have the front strut top mounts or bearings ever been replaced?”
- “Does the steering feel stiff or jerky when turning slowly?”
Now check the Mazda Mazda3 you are actually looking at
Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.
Where this comes from
Mazda Mazda3 buyer questions
Is bk front strut top mount bearing wear and clunking serious on a Mazda Mazda3?
We rate it major and common on the Mazda Mazda3. The upper strut bearing plate on BK-generation Mazda3 deteriorates from water ingress into the unsealed bearing housing, allowing the thrust bearing races to develop corrosion pitting and flat spots. As the bearing loses its ability to rotate freely, the strut binds during steering lock changes and then releases suddenly, transmitting a sharp clunk or knock through the strut tower into the cabin, most pronounced at low speed when parking or traversing sharp dips.
How much does it cost to fix on a Mazda Mazda3?
$280 to $700 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.
Which Mazda Mazda3 years are affected?
Our research records this fault on the 2003–2009 Mazda Mazda3. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.
How do I check for it before I buy?
With the vehicle stationary on level ground, have an assistant turn the steering wheel lock to lock slowly while listening at each front strut tower for clunking. Compress the front suspension by pushing down on the bonnet and release to reproduce binding. With the front wheels raised, check for roughness and stiction in the strut bearing by rotating the hub assembly. Inspect the rubber upper mount isolator for cracking and separation. Look here: Front strut top mount bearing plate beneath the engine bay strut towers, both sides