The short version
- A Subaru wheel bearing complaint is usually a rear one, which is unusual for any make.
- Owners report water getting trapped in the knuckle bore, where it corrodes the joint and takes the bearing with it.
- Symmetrical all wheel drive means every corner is a driven corner, so there is no easy end of the car.
- There is a bulletin on rear bearing failures with a revised backing plate. Worth asking about if yours is still in warranty.
On most cars the front bearings work harder and fail first. Subaru owners keep reporting the opposite. The pattern is consistent across Forester, Outback and Crosstrek forums.
The explanation people give is about water rather than load.
Why the Subaru wheel bearing complaint is a rear one
Owners and technicians describe water collecting in the knuckle bore. It sits there against the outside of the bearing.
Corrosion then builds between the bearing and its housing. It attacks the fit and works inward toward the seal.
Multiple owners report replacing the same rear corner more than once, some several times. That points at the housing rather than the part.
What corrosion does at that joint is on the corrosion page and the spun bearing page.
The bulletin worth asking about
A technical service bulletin covers rear bearing failures. It replaces the original backing plate with an updated design.
Whether it applies depends on model and year. A dealer will usually only mention it if asked.
Check the current bulletin list against your own vehicle identification number. Summaries like this one get out of date.
Coverage generally is on the warranty page.
Where owners and this site disagree
Owners often suggest coating the knuckle bore so the next bearing comes out easily. The instinct is understandable. The fix is not.
Friction at that joint is part of what stops the outer race creeping. Lubricate it and you trade a hard removal for a spun bearing.
The right answer to corrosion is to clean the bore back to bare metal and measure it. That is on the anti-seize page and the bore measurement page.
Subaru wheel bearing arrangements by model
| Model | Front | Rear |
|---|---|---|
| Forester | Pressed into the knuckle | Pressed into the knuckle |
| Outback, Legacy | Pressed into the knuckle | Pressed into the knuckle |
| Impreza, Crosstrek | Pressed into the knuckle | Pressed into the knuckle |
| Ascent | Pressed or hub unit by year | Pressed or hub unit by year |
Read down the table. Both ends are press work on most of these, which is why neither end is the cheap end on a Subaru.
The procedure is on the press in page and the options without one on the no press page.
All wheel drive changes the picture
Symmetrical all wheel drive drives every wheel, so every corner carries an axle shaft and a driven hub.
That removes the usual shortcut, where the rear of a car is simpler and cheaper than the front. On a Subaru the two ends are much closer.
What drive type changes is on the drive type page.
Diagnosing a Subaru wheel bearing
- Do not assume the front, because the rear is the more reported end on these.
- Coast in neutral at the same speed, to separate the differential from the bearing.
- Try light braking at a steady speed, which unloads some rear designs.
- Rock each wheel at twelve and six with the parking brake released.
- Compare hub temperatures after a drive rather than judging one alone.
Those are on the rear symptoms page, the differential page and the checking page.
Common questions
Why do Subaru rear wheel bearings fail so often?
Owners and technicians point at water trapped in the knuckle bore. It corrodes the joint and works inward from there.
Is a Subaru wheel bearing a press job?
On most models yes, at both ends. That is unusual and it is why neither end is cheap.
Should I put anti-seize in the bore?
No. It removes the friction that stops the race creeping, which trades a hard removal for a spun bearing.
Is there a bulletin?
There is one covering rear bearing failures with a revised backing plate. Check it against your own vehicle rather than a summary.
Why has the same corner failed twice?
That points at the knuckle rather than the bearing. Clean the bore properly and measure it before fitting another.
Does all wheel drive make it worse?
It makes every corner a driven corner, so there is no simple end of the car to work on.
Which Subarus ask about this most?
Forester and Outback, then Crosstrek and Impreza.
By model
- Forester Wheel Bearings: Why the Hub Fights You wheel bearings
- Outback Wheel Bearings: The Rear Is Where Years Matter wheel bearings
- Subaru Ascent wheel bearings
- Subaru Baja wheel bearings
- Subaru Crosstrek Wheel Bearings: The January Build Date wheel bearings
- Subaru Impreza Wheel Bearings: Trim and Build Date Splits wheel bearings
- Subaru Legacy Wheel Bearings: The Part It Shares wheel bearings
- Subaru WRX Wheel Bearings: WRX or STi wheel bearings