Inspecting Your Hub-Piloted Wheel End

By: John O

Video Transcript

Hi, I’m John Auto, category manager at Parch for trucks specializing in wheel and systems, and today we’re going to continue our discussion about the hub, pilot wheel and system.  


We’re going to get into the nitty gritty of inspection, which is extremely important. You have to inspect the wheel end system going in, taking it apart, as well as putting it back together. The first thing you’re going to see when you walk up to a wheel end is a tire and a wheel. You’re not a tire expert, but if you see bulges anything abnormal in the tire, cuts, stop, call a tire specialist. Have them come in and take the wheel off and remove the tire and service the tire.

When you begin your inspection, you’ve inspected the wheel. You walk up to the to the to the wheel, you see the wheels. The first thing you see and this one doesn’t have the nuts attached is to look for streaking, rust streaking around there. Specifically, you’ll see it more readily on the steel wheel versus aluminum, but watch for that streaking, that streaking could be coming out of a crack, or it could be coming that between the nut in the flange and the stud and it could mean that possibly the wheel has been loose. The nut has backed off a little bit and it has been very dry and not disassembled in a long time, so thus, it’s gotten rusty.  You cannot see a split in the inside of the rim because it has the rim portion of the wheel because it has a tire on it. But you’re looking for the condition of the wheel on the on a white wheel. You will often see flaking in the condition of the paint if there’s a great deal of pitting, it has to be possibly looked at and taken out of service.

So you’ve come to the wheel you’ve inspected, you’ve looked for cracks. You’ve looked for galling on an aluminum wheel or pitting on the surface of the disc. Now you have to address the studs and the nuts. The studs and the nuts are classified as hardware. The condition of the stud is extremely important. If you happen to have a stud sticking out that looks very much like this, you know you have an issue.  one is broken off. If one is broken off. When you go to put it back together, you must replace one on either side. If more than one is broken, you have to replace them all. So looking for that broken wheel stud is extremely important. Looking for poor wheel nuts, wheel nuts that are in poor condition, either the washers very loose. It doesn’t turn smoothly or the back surface is not flat. Those are out of service conditions, take them out of service condition and set them aside, so that you don’t try to put them back on. This is where your wire brush starts to come in handy. You’re going to want to start to clean as you take it apart. You inspect as you go in, you inspect as you go, you clean on your way in and you double check your cleaning on the way out.

So you’ve gotten the wheel off, you’ve checked the nuts and you checked the studs, you’ve thrown out that bad nut and then you begin to clean up again. So you haven’t quite gotten down to the drum, but you’re going to look at the drum as well. Not all technicians can take the drum off, but those that are, they’re going to do the exact same thing. They’re going to look for the disc wear on the disc, on the crack, on the disc, and they’re going to look at the surface on the front and the back for cracks, paint, there should be no paint on the back at all, and there should really be no paint on the front. Paint can cause clamp force issues, which we will discuss further.

So you’ve gotten it apart. Now you’re looking at it and this one happens to be clean. This is brand new, so it’s not rusted, but you could conceivably have a stud as you’re taking it apart that looks like this.  You’ve taken it apart, you’ve put the wrench on it and it’s backed off and that’s what you get. So you certainly set that aside and realize you’ve got to change your stud. The other ones may look so you may look good, so you take your wire brush or your drill with a wire wheel on it, but certainly not a grinder with a grinder disc. You’re trying to clean things up, so you’re cleaning the studs, you’re cleaning these surfaces all here. These are all surfaces that must be clean to put it back together in order to get the proper stack. That’s what’s known as the stack is the hub, the drum and the wheels known as the stack.

And we need to pull that together and get it to torqued properly and get the proper clamping force to keep the wheels on the vehicle. Here we have an aluminum hub that came off of a vehicle. This is how why you have to inspect. You have to inspect on the way in and we inspect on the way out. Take the out of service components out, set them aside. Get the replacement components before you get ready to put it together.

So what you’re looking for, you’ve looked at the stud, you’ve looked at the nuts you’ve separated those, you know, you either may have to replace one or two or maybe they’re OK. But look, in this case, how bad these are, these are rusted really badly. Once we took the wire  brush to them, perhaps they would clean up and be fine and work fine. But you can’t tell right under there, but look at the outside of this, it’s corroded.  And I indicated that when that drum goes on, there can be interference here. And if this is built up with corrosion, that drum may not set and pilot properly, and that is the key, to pilot properly.

Also in here, these are the pilot pads they don’t stand out like they do here. They are machined in the barrel of this particular hub. And if they are worn and if this pilot pad down here, this little step is not clean, that drum is not going to seat, right, the wheels aren’t going to seat right, you’re going to have loose wheels when you torque it down.

We’ve done our inspection on the way in. We’ve looked for cracks on the hub on the face of the wheel, in the face of the drum. We’ve looked at the condition of the studs and the nuts, the pilot pads.

We’ve determined that anything that should be taken out of service has been taken out of service. You have your new component, you’re ready to go to reassemble. The drum is going to be the first component that goes back on, and once again, it’s going to pilot.

So you piloted your drum, you’ve cleaned your hub So you know that drum is sitting down nice, that it’s not hung up on the edge of that flange of the hub. It’s not hung up in the pilot pad down in here that step and as you put this on, you’ve taken a little bit of 30 weight oil, 30 weight and you’ve put a little film on a hub on the pilot, a couple of drops and then you take your finger and just give it a wipe.

We’re ready to install the wheel. So you slide the wheel on now you’re ready to begin to pull the stack together even more by starting your wheel nuts. First, with a drop or two of 30 weight oil, only 30 weight, two or three drops at the end of each stud. Don’t move it around, just let it sit there one at a time, two or three drops of 30 weight oil between the flange of the nut and the nut body. Now you’re just going to begin to start to tighten them up by hand. In the next session, we’re going to go and begin the final stage, the torquing of the wheel to develop that stack clamping force going forward.

Thank you for joining us as we discussed inspection, inspection on the way in inspection on the way out as we reassembled, disassembled and reassembled. Should you have any questions, please reach out on or contact one of our branches for more information.