All-wheel drive means power goes to more than one set of wheels. That can help with traction, and it also changes what parts you listen to during diagnosis.
A unitized wheel bearing and hub assembly combines the wheel bearing and hub into one sealed component. This design simplifies service because you replace the whole unit, rather than pressing bearings in and out.
The parking brake uses small friction pads/shoes to hold the car in place. In this repair, those parts are in the way, so they have to be taken out to reach the bearing hardware.
Wheel bearings are described as “individual wear items,” meaning they often fail at different times rather than as a matched pair. The episode explains that you typically replace them when they develop symptoms like noise or measurable play, not just because mileage is high.
The segment focuses on how an owner can listen for wheel-bearing symptoms and differentiate them from other drivetrain noises. It emphasizes speed-related noise and steering-direction changes as practical, real-world diagnostic cues before visiting a mechanic.
The hosts say a failing wheel bearing often makes a humming (or growl-like) sound that gets louder as speed increases. This is a key diagnostic clue because the noise pattern changes with driving conditions.
They say a front wheel bearing can make noise that changes when you turn the steering wheel. That turning-related change can help point to the front versus the rear.
When you turn, your car’s weight shifts to one side. That can make a worn wheel bearing sound worse in one turning direction than the other.
LIVE
Hi, it's Mark Bossard. I'm here with Bernie Pawlik, Pawlik Automotive in Vancouver, Vancouver's
best auto service experience. And we're talking cars. How are you doing this morning, Bernie?
Doing very well. So today's guest is a 2014 Sienna, Toyota Sienna van. What was going on with this
vehicle? So this vehicle came to our shop with some complaints of drivetrain noises. So we
performed our diagnostics, road tested the vehicle, brought it up on the hoist. It's an all-wheel drive
able to run the vehicle on the hoist and listen to the various drivetrain components. We found a
couple of things. The transfer case is noisy and also the right rear wheel bearing was badly worn.
So I'm going to talk about the right rear wheel bearing replacement on this episode.
Okay, so let's jump right into the pictures. That's a pretty straightforward kind of
repair. Is that right? These things can get stuck and seized into place, but generally it's
a lot easier than the transfer case replacement. And wheel bearings are fairly common on many
vehicles given enough time. This vehicle had almost 240,000 kilometers, so it's been well used.
A lot of mileage. So here's our vehicle. Here's our vehicle. Good shape for sure. And what do we
have here? Yeah, so this is the old wheel bearing. It's called a unitized wheel bearing and hub
assembly. These are probably the best wheel bearings to replace on cars because they're all
kind of a one-piece component. You get the new hub, you get a new wheel bearing, and it bolts in.
So the part that's facing us is the flange that bolts onto the knuckle. And the wheel bearing is
contained inside there, so you can't see the wheel bearing. It's all hidden away inside, but these
are kind of the best wheel bearings, I think, in terms of replacement. You get everything complete.
There's another view of the old part. The other direction. Yeah, the other direction. Yeah. And
where you're moving your pointer there, that's where the wheel bolts up. So the disc brake
rotor fits on there, and then the wheel bolts onto that. Let's see that clear here. Yeah,
this is the new bearing, the nice shiny new bearing in place. Behind where that flange
would be is where the parking brake shoes go. So we removed all those components to get at the nuts
to remove. So it's a bit of work. You have to take the brake caliper disc off and the parking
brake shoes, and then put everything back together. So often when you're doing this kind of work
in suspension, you do both sides. So was that needed in this case?
No, not for wheel bearings. Things like shocks, springs, brakes, it's important to do them
because they're wear out components, but bearings are very individual wear items. We don't do two
of them if it's not necessary. If they're both noisy, then we'll do them. But if they're not,
the other bearing could last for another 10 years. It's like you just don't really know with
wheel bearings. They're kind of a hit and miss. Once they start making noise, that's when you
replace them. Or if they have play in them, if you take the wheel and you wiggle it back and
forth, if it has some play, then you would replace the bearing. But other than that, it's good to go.
So once it was replaced, sound gone? That sound was gone. Yeah, it was all good.
Yeah, wheels running free. Yeah, more happy motoring. Exactly. That's right. So just
diagnosing this as an owner, what am I listening for? What kind of sound is this going to be?
This tends to make a humming, kind of, maybe a growl or a humming kind of sound. And the
faster you start moving, the louder the noise becomes. It's not always a wheel bearing. As I
mentioned, there was a transfer case problem too. But in this case, we're just talking about the
wheel bearing. So a wheel bearing, it'll make a humming sound and you start off at a low speed,
and you might not hear it. And then once you start going faster, especially on the highway,
it gets louder and louder. Is there any difference between a front wheel bearing and a rear wheel
bearing? Not so much a sound is concerned, but often you'll find the sound can change on a front
wheel bearing more so than a rear by where you're turning the steering wheel. For instance, sometimes
if you go around a curve, the noise stops or it'll actually get worse, depending on which
direction you're turning. That can often indicate whether it's front or rear. So that's just the
load shifting as you're going around. Yeah, the load shifting and sometimes the wear on the bearing
is such that it makes more noise in one direction than the other. So when you're hearing that noise,
time to get it checked at your local mechanic or obviously come into Pollock Automotive. If you're
in Vancouver, your best auto repair service is at Pollock Automotive. You can book your appointment
at PollockAutomotive.com or you can call them to book your appointment, 604-327-7112. You have
the book ahead. They're always busy, Pollock Automotive in Vancouver, BC, Canada. Thanks so much for
watching and listening. Thanks Bernie. Thank you Mark and thanks for watching.
About this episode
A high-mileage 2014 Toyota Sienna came in with drivetrain noise, and the shop found both a noisy transfer case and a badly worn right rear wheel bearing. The discussion focuses on the wheel bearing replacement: a unitized hub assembly that bolts in, but still requires removing the brake components and parking brake shoes. Bernie explains how wheel bearings usually fail, what a humming or growling noise sounds like, and how turning can sometimes change the noise on front bearings. The repair eliminated the sound and restored smooth operation.
