2004 Ford F150, Rear Differential Overhaul
Mark: Hi, it’s Mark from Top Local, we’re here with Bernie Pawlik of Pawlik Automotive in Vancouver; Vancouver’s favourite auto service experience, 16, 16, 17 time winners of best auto repair in Vancouver as voted by their customers. How’re you doing Bernie?
Bernie: I’m doing very well.
Mark: So we’re going to talk about a Ford F-150, you did a rear, some rear differential work on this vehicle, what was going on with this product?
Bernie: Well, this vehicle had some noises coming from the back end, noticeable when you’re driving down the road, there was a bit of a growling sound and so that’s what we, what we were repairing on this vehicle.
Mark: So what did you determine the cause to be?
Bernie: Well the causes was, was inside the differential, the bearings were noisy and how we find that you know when someone brings a vehicle to us for a noise like this, we will road test the vehicle, listen to the noise and quite often we get a pretty good idea where it might be coming from. From there we put it up on the hoist and we have a listen to the bearing, have a listen to the bearings and the drive train with a stethoscope and we can hear, we can listen to different areas around the underneath the vehicle, so there’s four bearings inside the differential and there’s also a bearing on this particular truck out at each wheel; it’s the axle bearing, so we have listen to those and then we can kind of determine where the noise is coming from and on this vehicle the noise, it was noisiest in the differential itself.
Mark: So, which bearing did you find worn out?
Bernie: The culprit was the one of the carrier bearings; the carriers the big piece that the axels slide into that section. It’s a large piece with the ring gear and there’s a bearing on each side of that, you know there’s also pinion bearings, that’s the shaft that attaches to the drive shaft and that’s the sort of small piece, I don’t have pictures of everything but I do have one photo to share of our worn out bearing which is kind of cool to look at, so here is the picture. This is the close up view of the carrier, so sort of where my mouse is pointing, that’s, that’s one of the bolts that holds the ring gear to the differential and the ring gears on the other side, we can’t see it. This is the carrier bearing and you can see it’s, that should be a beautiful shiny smooth piece of metal and as you can see it looks like you know, there’s just chunks and pieces missing so that was the cause of the noise. That was the worst bearing, the other ones all had some wear but this one definitely was the worst.
Mark: So when you do this, do you replace all the bearings?
Bernie: We do, yes we do, we replace them all because they’re all worn to a certain extent, also when this is worn of course there’s little metal filings and pieces and they’ve gone through the whole differential and you know, fortunately usually bearings are the most common thing to wear out in differentials, you know if you let them get bad enough and the bearing actually start getting sloppy then you start getting play in the gears and you can start breaking gears but generally bearings are the most common things that wear out. If you change them, you know, right when you start hearing noise usually you don’t need to do a whole lot more.
Mark: So here is a esoteric kind of thing, are there much difference in sound depending upon which bearing it is?
Bernie: Yeah, there is actually. You know for us, you know to provide an actuate estimate to our customer and we always like to know what, which part, which you know which piece is noisy, differentials are interesting because they take the, the drive shaft which is basically the longitudinal motion along the vehicle say in a rear wheel drive car and they and, and that’s bolted up to the pinion which spins at the same speed as the drive shaft which is coming to the back of the transmission so it’s spinning at a very high speed, it attaches to the ring gear and the differential carrier and that, that gear is usually about three to four times the size of the pinion gear here so it slows the rotation down so you can generally if you listen, if it’s a differential noise, if it’s a pinion bearing the noise will be a lot, it starts happening a lot faster, as soon as you get moving the noise gets louder immediately whereas a carrier bearing, it takes a little while because it’s rotating at the speed of the wheel so you can almost, I’ve had quite a few vehicles where I go, it sounds like it’s got a bad wheel bearing and then you listen and all the wheel bearings are quiet and it’s, it’s a carrier bearing because it’s spinning at exactly the same speed as the wheel so this is how we can kind of determine which bearing is worn . . . carrier bearing, it’s going to be a little subtler in sound than pinion bearings but you know, it depends from vehicle to vehicle.
Mark: Sure, so how did you repair this?
Bernie: This differential? Well we basically replaced all the bearings, cleaned everything so we removed, dismantled everything, cleaned it, then cleaned it, then reassembled it, made sure all the back lashes in the gears and the ring gear patterns was proper and yeah, changed all the bearings, cleaned everything out, that’s the important thing and then reassembled it. The bearings are you know are all pressed onto, it’s a fair bit of work to press everything on and off there, it’s a tight fit, we have good hydraulic presses and tools that make life a little easier.
Mark: So do you see a lot of differential issues in Ford trucks?
Bernie: We do a fair number of them but they’re actually overall quite, overall they’re quite reliable because we do service an awful lot of Ford trucks so I can’t say that differentials are really a weakness or a problem especially I find a lot of the larger ones that you know, that the three quarter ton and one tons almost seem to have less differential problems because they’re just built so tough but you know if for someone who’s hauling a lot of really heavy loads continuously, those, those differentials will wear but if you’re not hauling a lot of heavy loads those differentials can last almost forever.
Mark: So there you go, if you are looking for anything growling in your back end these are the guys to see in Vancouver, Pawlik Automotive, you can reach them at 604-327-7112 or check out their website pawlikautomotive.com. We have four years plus of videos on there, tons of information about every kind of vehicle, just about that there is. Thanks a lot Bernie.
Bernie: Thanks Mark.