Mark: Hi, it's Mark Bossert. We're here with Mr. Bernie Pawlik. Pawlik Automotive in Vancouver, Vancouver's best auto service experience. 25 time winners of best auto repair in Vancouver as voted by their customers. We're talking cars. How are you doing Bernie?
Bernie: Doing well.
Mark: So today we're talking about a 2012 Nissan Xterra. I don't even know if they make these anymore. What was going on with this vehicle?
Bernie: Yes, this vehicle, the owner thought there may be a bad wheel bearing. There was a noise when you drive down the road and they'd had a wheel bearing replaced previously. So assumed another wheel bearing had gone on the vehicle. So that was why the vehicle came into the shop.
Mark: So what sort of testing and diagnosis do you do? I'm going to assume a road test.
Bernie: Yeah, road test is the first thing. That's probably the major part of that. There's sort of two parts to any sort of possible wheel bearing issue. One is the road test to see where the noise is coming from, trying to pinpoint it. It can be tricky. Sometimes wheel bearings, you think, oh, it's the right front one. And it ends up being the front left one or somewhere else. But often it's pretty distinctive.
This was an interesting road test. So we drove the vehicle and you could hear a sort of the usual, like normally when a wheel bearing is bad, it makes a sort of a droning humming noise, like a deep humming noise, and it gets louder, the faster you go. And often if you make a turn, the noise will stop, it'll lessen or get worse, depending on which way you're turning the steering wheel, or if you're going around a curve makes a difference.
So this one was quite a bit different. Took a fair bit of speed to get, but it was more like a kind of sound, like a more of a, you know, a different type of noise. But it did sound like it was probably a wheel bearing type of noise, but just very unusual and different. Not the usual humming type of sound.
So that's the first part of the diagnosis, just a road test. Then the next part, put the vehicle up on a hoist and run the vehicle. Fortunately, this vehicle is a four wheel drive. So you can put the vehicle into four wheel drive and run the vehicle so all the wheels spin. And that way we can go around with a stethoscope and listen to each wheel bearing or axle bearing and find the noise.
Mark: So what did you find?
Bernie: Yeah, we found that the left rear axle bearing was worn out. So this vehicle uses a solid rear axle. So the axle bearings are a slightly different design than say a wheel bearing would be on just a normal spindle type or an independent suspension. The design is different.
Mark: So what is the difference in names mean between axle bearing and wheel bearing?
Yeah, so they're all wheel bearings, but because it's in a solid axle, it's considered to be an axle bearing, not a wheel bearing. If it was an independent rear suspension vehicle, it would have what's called a stub axle attached to a flexible drive shaft with CV joints. That's considered more to be a wheel bearing, but essentially it does the same function, but it's how it's built.
So generally an axle bearing, on a solid differential will either be and I'm talking about a rear one because it doesn't have any steering capabilities. The bearing will be either pressed onto the axle itself and the race is pressed into the axle housing. Like a lot of GM's, the actual bearing will be, it's like a roller bearing that is actually pressed in the axle housing and the axle just slides in and rides on that bearing. So the removal and replacement processes are slightly different between the two.
Mark: What's involved in the process of replacing it?
Bernie: So you have to remove the axle from the vehicle. In this case, you can unbolt the axle from the wheel. And of course, the brake components have to be removed to access it. It's actually disc brakes in the back with parking brake shoes. So all those components have to be removed. And then from there, you can unbolt the axle and slide the axle out of the axle housing. I'll just get into a picture right away.
So this is the actual axle slid out of the rear differential housing. As I mentioned, I made kind of a funny sound and you can see right away that there's, this is the bearing. Where I'm moving my mouse pointer here, it's a tapered roller bearing.
You can see that there's actually one of the rollers is missing. So that was kind of a dead giveaway that the problem right there. So that bearing and actually disintegrated and busted apart. You can also, if you look closely, unfortunately, the picture doesn't enlarge any bigger than this. You can see this is smooth and shiny, but these edges look kind of rough, but that's actually the bearing pitting and coming apart.
So this bearing was in very, very, very bad shape. Often they'll start making noise far before that. So it was a good thing that the owner replaced it at this time because, you know, it could have gone for a catastrophic failure. So what else is involved?
So once the axle is pulled out to replace the bearing, this shiny piece here, this is a collar that holds the bearing onto the axle. And so this is all press fit. So normally what you do is you either cut these with a cutoff wheel or you drill it, you crack it. Whatever you do, you break this ring off. And then from there, you pull the axle off. There's an oil seal back here. These will frequently fail and leak before the bearing, but if these seals leak, you still have to pull the bearing and collar and everything off and replace the whole unit.
We have a hydraulic press where we press, you cut, break things off, you press it off and use a hydraulic press and you put everything back on. So it's definitely not a backyard kind of job. You can't just do it with hammers and bashing things. You may be able to take it off like that, but you'll never get it back on. That's for sure.
So that's kind of the process with this bearing. And then the race, of course, needs to be pulled out of the housing and then you know, inserted back in. And again, that's a slight press fit, but it doesn't require any hydraulics. That's sort of a hammer and proper tools type of fit.
Mark: I have a question. What's that toothed gear that we see in the picture?
Bernie: Oh, yeah. Hang on. I'll just get back to the picture. That is the ABS ring. It's a good question. So for ABS brakes, you have a toothed wheel here and then there's a magnetic sensor that sits in a housing. I guess that would be, I'm trying to think where the housing would be.
Anyways, there's a magnetic sensor that sits near to this. It sits stationary and it sends an electrical signal to the ABS brake module to adjust the anti lock brake system. And sometimes these things will get damaged. You know, it's impossible to change the bearing without damaging these rings.
So that adds an extra cost too. It's an added complication and you know, we do our best to remove it, but sometimes it's impossible depending on the clearances. In the case of this vehicle, it didn't require a replacement.
Mark: Is there anything else that you have to address with that repair? Do you have to do both sides or?
Bernie: No, we just do one side, just do them as they need to. There's not really any savings in doing both sides. Some vehicles, it would make sense to do both. On this particular vehicle you don't need to. It is basically the axle unbolts. So it's a complete one side job. The other side is not making any noise. It's fine for now. So what else we do? Of course, you see that that bearing disintegrated and lots of little metal pits. Of course, where does that metal go?
Well, it's inside the differential housing mixed in with the oil. So we drain the oil out. We clean it as best we can. And then we actually clean the axle tube. So the differential sits in the middle, and there's an axle tube that goes out each side. So we clean that axle tube very thoroughly.
I saw Ed had a shop vac and brake clean. In the past often sprayed in there with cleaner and use rags on a very long extension or a pole to wipe out all the material because it usually accumulates inside that axle tube. And it's pretty important to wipe it out. Otherwise, you know, over time, those little flakes will float around and they'll get into the bearings and, you know, it's not the best thing for them.
Mark: So how'd the vehicle operate after everything was put back together?
Bernie: Oh, it's good. No more noises. And as I said, I mean, that bearing was exceptionally badly worn. A lot of times wheel bearings can be worn and you won't really, you take them apart and you go, oh, well, there's a little pit in the housing, on a race. It's causing it to make noise and it could last a very long time.
But there's a point where it gets bad. And, you know, if it fell apart, even worse, that we'll be flopping up and down. And the axle could actually, if something happened, it could actually slide right out of the, that that'd be exceptionally extreme, but could happen.
Mark: The wheel would come off and you'd be in trouble.
Bernie: Yeah. It wouldn't be a good thing.
Mark: How are Nissan Xterras for reliability?
Bernie: Yeah, it's a good vehicle. I like them. They're a real truck vehicle as opposed to like a, Nissan Pathfinder is much more popular, but an Xterra is actually a, it's a full framed vehicle. So this one, you know, it has a solid rear end. So it's not going to give you the smooth feeling of a Pathfinder, I'll just compare it to a Pathfinder, but it's much better off road type of vehicle. And they are quite reliable. They're solidly built. They're kind of equivalent to any other Nissan product, you know, pretty good. Not bulletproof like anything, but which is good, keeps us in business. But things wear out, but they're a pretty good vehicle overall. I'd recommend them.
Mark: If you're looking for service for your Nissan or your 4x4 in Vancouver, the guys to see are Pawlik Automotive. You can reach them on their website, you can book there at pawlikautomotive.com. Or you can call them (604) 327-7112 to book your appointment. You have to book ahead. They're always busy. Pawlik Automotive, Vancouver, BC, Canada. And thank you so much for watching and listening. We appreciate it. Thanks, Bernie.
Bernie: Thank you, Mark. Thanks for watching.
