I am an avid fan of trucks and heavy equipment. It has been a long time now since I have done a truck, but am heading down that road soon.

I drive buses and have been trying to get into the mech area to see under the hood, but haven't had much luck finding the time...

My question is I'm sure very simple, but on an axle that has double wheels (4 wheels) how are they mounted together and on the axle. I've tried to find pics on the net, but can't seem to figure out what everything is called in English...

TIA

Well, Brian, the answer is it depends on what type of wheel you have for your tandem set-up. I'm going to assume that you are talking about heavy trucks here.

If you have disk wheels (Alcoa or Budd), they are mounted onto the hub similar to a car tire. There are usually 8 or 10 bolts that come out of the hub, and the wheel is mounted directly onto the bolts, then the lugnuts are tightened down.

If you have spoke wheels (sometimes called Daytons, Spyders, or Chicago Wobblers), the setup is completely different. The spoke wheel is actually part of the hub, and the tires with a rim are held in place with wedges.

Hope this helps.

Jim

As Jim said, 90% of heavy truck wheels mounted as dual's are what we call in the industry - hub piloted. That means the wheel hub holds the brake drum in place using 10 long studs that the wheels are bolted directly to.
Dayton wheels have the tires mounted to seperate rims, and are held in place with 6-8 wedges holding the wheel in place.

Art

Thanks to you both for the help!! You have given me the vocabulary to find what I am looking for!!

You were spot on Jim when you assumed heavy trucks.

The wheels are definitely Alcoa-types, and given the age of the buses I drive they have to be hub-piloted.

Thinking about it, I know very little about the vehicles I drive...

Let me add this I guess, the rim it'self has a slightly outward dished side and an open side...when mounted to the brake hub the 1st rim is mounted whith the open side towards the inside{air valve facing outward}, then another rim is added with it's open side facing outward{air vavle facing inward} and they're both bolted in together, or sandwiched via the lug nuts.
Front single rim has the slightly dished side facing out - open end in...
Newer rear super singles here are really a double width rim that fits a single double width sized tire/ single attachment point. These are a takeoff of the super singles that were on the fronts, but since they're wider{too wide I think for the front} they are back only. Oshkosh liked using super wide singles front and rear.

Thanks Bob!

Are the rims the same for front and back? If I don't use super-singles, can I (in theory) take a wheel from any position and use it up front? Or are there tread issues?

During a short break yesterday, I went out and looked at the tires on the bus I was driving. A colleague came up and asked what I was doing "looking at the wheels"... Wouldn't surprise me if I get called into the boss!!

Generally there are different treads between drive tires & steer tires. On a model, I wouldn't worry too much about it.

Jim

I noticed another thing today, taking another walk around the buses I drove, that basically very few of the tires were of the same make...

Is it that way for real-life trucks too? If so that might make an interesting detailing detail!!

Tires will vary ( brand and tread ) upon the price the shop gets for them. Every company is on a budget now adays, so the cheaper brand offered is what you end up with. So long as they are the same size on the drives it wont matter much, stears should be the same side to side, tread and size; or you'll have a hard time keeping it straight on the road. The last truck I drove had 3 different types of drives but up front, they were the same. Though I will say that I have seen stears of different type tread but the same size, after road service comes for a flat. At that point most drivers are just happy to be moving again.

I have seen trucks come in to our shop with six, eight, heck even ten different tires on all the rims. Like Jim said, most companies are running tight budgets, and it is not uncommon to see re-caps next to new tires.
Lots of companies also run steel wheels on the inside of the duals, with aluminum on the outside to save money as well.

Art

Thanks again Bob and Art for your replies!!

We are definitely on a budget at work!! With a fleet over 500 strong that is a lot of wheels...

Now I don't want to sound like a know it all but I would worry more on how you hold the steering wheel with your hands then where the tires go mounted on the truck because most companies have a garage come out and do all the tire work and other work.

See I have seen many of people driving with their fingers down in between the steering wheel post, even them so called best drivers in the world on that Ice Road Truckers because what I seen the most of them doing I would fire them, because anyone that drives with their fingers inbetween them inner post and if they get a steering tire blow out they will most likely get one broken finger, maybe more and trying to keep that truck under control with their fingers broke would be next to impossible, see it is hard enough to keep the truck under control with no broken fingers.

Well the next time if you watch that ice road truckers and see if they don't lean back in their seat with their fingers inbetween the steering wheel posts, then with them running on all that rough roads and leave their fingers between the steering wheel posts does that sound right to you.
Thank You For Your Time

Kerry, I'm sure you mean well, but I don't understand what your post has to do with me building truck models?

It just happens to be that I drive buses, and they have some of the same parts as trucks, but what does that have to do with how I hold my hands on the steering wheel? And since I do drive heavy vehicles why shouldn't I be able to better understand what I work with??

I have driven so long that I have had blow-outs, so I do have experience with them. I also understand the danger of having your fingers in the wrong places, but to be willing to fire someone for doing that I'm sorry, but that is just too stupid - I'm glad I don't work for you and that my employer thinks completely different than you...

Now I have never driven a bus but I do know they rode a lot better then the union tractors we used to drive in the 70's with a 156" wheelbase.

Now if you drove one of the bigger buses with dual wheels then you have it, the trucks are the same as the big buses.

Back when putting your thumbs behind the steering post was when Truck driving still paid good union wages and the companies made you have a 156" wheelbase tractor that would put tears in your eyes then they made you run team and none of the tractors had power steering.

I guess I owe you an appoligy because I somehow thought you were trading in a bus for a truck.

No on that deal about a driver driving with their thumbs in the spokes of the steering wheel see back when I was in the union we had to run team and the driver had you life in his hands also so when you are back there a sleep you want the guy driving as good as they can.