Toyota SR5 Pickup Rear Differential Replacement
Mark: Hi, it's Mark from Top Local. We're here with Bernie Pawlik, Pawlik Automotive in Vancouver. Vancouver's best auto service experience. 22 time winners of Best Auto Repair. I love saying that. 22 time winners of Best Auto Repair in Vancouver as voted by their customers. And we're going to talk about a Toyota pickup today. How are you doing Bernie?
Bernie: Doing well, and I love it when we say 22 time winners too. It's an awesome honour.
Mark: So your differential replacement, what was happening with this Toyota?
Bernie: The differential had, something had seized up in the rear differential. Something had broken. The vehicle was towed into the shop on a flat deck and carefully placed on the ground right in the hoisting position. So we could take it apart because it wouldn't roll. Well, we actually did manage to get, make it move, but it made some pretty horrific bangs as we moved it. So yeah, the rear differential had basically blown, something had blown apart in the rear differential.
Mark: So what did you find when you looked inside?
Bernie: Well that's one of the reasons I wanted to do this podcast because there's a lot of cool stuff to look at here. So just to explain the procedure on, well, you know, we'll just look at some pictures and then talk. So there's the inside of the differential.
So little bit on Toyota. So on these particular Toyota pickup trucks, the differential, the actual differential assembly is a drop in type. You can unbolt the whole differential from the housing, which makes, you know, probably makes the repair actually a lot simpler. The axles come out quite easily. And then you just with I don't know, it's probably 10 bolts. You can pop the differential assembly out. So what we found was basically no oil in the differential. A lot of broken bits and pieces inside the differential and the pinion gear just completely blown itself apart.
So, you know, that's what's kind of fun about working on cars sometimes, is seeing the damage that can happen when things go bad. So, this is a better view of the pinion. It doesn't take much of that, you know, you don't have to know much about cars to know that that doesn't look good. But again, looking at the last picture, this is sort of a good side of the gear. That's kind of what the gear looks like when it's in good shape. I heard a little laugh there. Yeah. It's kind of interesting. This is the ring gear. So this is where the pinion gear moves against this gear.
And you can see that there's just a number of, you know, the teeth have just been pounded and mashed. I mean, this is really hard metal. I mean, if you hit it with a hammer, you probably couldn't even dent it. So you know, it's taken a lot of abuse. Again, there's a sort of a further away view. This is one of the bearings.
And even the bearings, you can see they're just brown. You know, they're just, everything just got cooked and overheated, and these bearings normally require a puller or a press to take them off of the differential. We were actually able to slide them right off by hand. That's how badly worn everything was. So essentially there was no oil in the differential. And that's really what kind of caused this whole thing to go bad.
Here's the view of the replacement differential. So this is a rebuilt unit that we put into the vehicle. You can see nice clean teeth and everything's nice and shiny. And of course we did put oil in that when we repaired it to make sure it lasts.
Mark: So let's dig into this just a little bit. So what does the oil do in the differential?
Bernie: So basically the oil just lubricates the gears and it lubricates the bearing. So differential, it's pretty simple. There's four bearings as one under this cap, one under that cap. And then there's two up here and those are for the pinion bearings. So there's four bearings. They obviously need to be lubricated and then the gears need to be lubricated. So there are two obvious gears here, the ring and pinion, but if you look inside this area here, these are the differential gears. I mean, the function of a differential is to transmit the longitudinally movement from the drive shaft out and change the angle of the movement out to the wheels. You also have to have gears to compensate for the different speeds of the wheels.
For instance, you're driving both rear wheels, but as the wheels are turning and you go around a corner, one wheel is going faster than the other. So there has to be a way to compensate for that. And that's what the differential does. There are gears inside here and they basically compensate for that different movement.
Otherwise the backend would just hop and bounce, and you can kind of get the feeling of that if you have a four wheel drive vehicle where it actually locks the two differentials, that when you go around a curve, things lock up because the wheels won't, the actual transfer case doesn't have a differential in it. So it'll cause cause the wheels to hop. At least most of them don't have a differential in them. So that it'll cause the wheels to lock up. This is something you can find in like a classic American style pickup truck where you could lock it in four wheel drive.
Couple other interesting things to show here actually, you might wonder, Well, what the heck is this, if you've never done a differential, what is this yellow?
This is like a marking paint. A really important thing with a differential is setting up the ring and pinion gear. They have to mesh a certain way and you can see a little bit of, the paints kind of marked off here. This is when when you put a differential together, you put this marking compound, then you rotate it and you look at the way the gear teeth are meshing together. And from there you may need to make adjustments. So you can see there's a kind of a contact pattern of the gear. If you don't do it properly, it'll howl, and make all sorts of weird noises and depending on how it's set, you know, it could howl when you accelerate or it could howl when you decelerate. So this is a kind of an important part.
This paint just washes off and becomes part of the gear oil. It doesn't really create any issue afterwards, but you can see there's a good contact pattern here and yeah, I think that's it for the picture show.
Mark: So how do you think this differential had ended up with no oil?
Bernie: I really don't know. I mean, I asked the owner, I said didn't this thing make a lot of noise for a long time? Because it would have been howling away and making a lot of noise. And there was a couple of issues. He said, no, I never heard it. I mean, one problem, and it's something we did fix, is the exhaust pipe had come disconnected after the catalytic converter.
So the exhaust was very loud so that that would mask some differential noise. And also this vehicle had like very large tires on the back end, you know, all over the vehicle. So again. Those tires can tend to be a little noisier also. So he never heard it. I mean, I'm sure that I would have, because my ear's kind of trained for that kind of stuff. But how it had no oil, he doesn't know. I mean maybe someone drained it out and forgot to fill it. I mean, everything was plugged in. There was no evidence of any leaks other than, one thing I didn't mention is as this differential blew up. It actually put a hole in the back cover of the differential housing. So that involves some extra repair. We were able to weld the hole shut, which is and excellent repair. But it was a little more involved than it would have needed to be. But you know, again, that hole wasn't the reason it leaked out oil because the oil was already gone before the hole was created.
So really don't know. And you know, sometimes a differential will develop like a leak from pinion seal and over time it'll spray the oil up. But we couldn't see anywhere that there was any evidence of oil leakage. So really hard to know. I mean, sometimes we were run these mysteries and just can't really quite figure it out. But it'd probably been driven for a while without any oil in it, you know to cause it to do what it did.
Mark: Having experienced this a couple of times with two different vehicles. It's really loud when it starts to howl so it took some work to ignore it.
Bernie: Yeah, I think so. Well, you know, people turn radios up and I'm not saying that the owner of this vehicle did, but, you know, there was a couple of things like loud exhaust that could mask it and, you know, maybe it just sort of developed over time and go, Oh, that's kind of like normal.
Anyways, you know, and this is a good reason that, you know, check your fluids regularly on your vehicle. Like you never know. You think, Oh, yeah, well, there's nothing leaking out. It's gotta be okay. But you know, who knows what happened. But a simple inspection of the fluid, you know, during an oil change would have been enough to, Hey, wait a minute. There's no oil in this unit or the level's low, let's top it up or replace it. You know, I say it's a bit of a mystery, but it always makes for some interesting repairs when stuff like that happens.
Mark: So how are Toyota pickups for reliability?
Bernie: Yeah, they're awesome trucks. I mean, they really are. I mean, this vehicle is getting pretty old now. It's a 92, you know, it's approaching, approaching 30 years old, but still really reliable. I mean they're a well-built truck. And you can certainly go off road and keep going places and I think they're still worth fixing and keeping going.
Mark: If you maintain it?
Bernie: If you maintain it. Yeah. Well you know changing the differential is all part of the maintenance program. And after we fixed it, the vehicle, you know, ran really well.
Mark: So there you go. If you've got a Toyota in Vancouver that you need some looking after, or you just want to maintain your vehicle so it keeps running reliably so you don't have to worry about it. The guys to call Pawlik Automotive, (604) 327-7112 to book your appointment. You have to call them book ahead. They're always busy. Check out the website. pawlikautomotive.com. Hundreds of articles on repairs and maintenance of all makes and models of cars. Over 600 articles on there as well. The YouTube channel Pawlik Auto Repair, hundreds of videos on there. Thanks for watching. We really appreciate it. Please leave us a review if you're enjoying what we're talking about and thanks, Bernie.
Bernie: Thanks Mark. And thank you for watching.