Talking about Wheels

[JIM CHALOUPKA]

As I moved along with the smart tire install I removed the drive wheels.

With their removal several studs broke off on the starboard hub, 5 to be exact, now that was scary.

This is an area of the bus that many don't think about and whose failure can be disastrous.

I will change them all. They are just as important as tires and I believe they should be given a "time in service interval" and maybe they have one and I don't know about it.

With this event I was motivated to do some research about studs. An important thing that I have found is that the fastening nut should be adjusted with a torque wrench and the last movement of the nut to its final torqued position should be through a minimum continuous movement of 90 degrees. I feel reasonably sure no one in this group has that capability! Even though many of us have the X-12 torque multiplying wrench and use a torque wrench with it, the movement of the nut is in small incremental steps and not a sweeping arc of 90+ degs.. The same would hold true for the impact wrench with a torque stick added behind the socket.

If I ever buy another used bus among the first things I will do is change all the wheel studs at the time of purchase.

JIM

[Jon Wehrenberg]

Jim,

What I saw was a film of oil (at least that is what it looked like) on the back of the caliper and extending around the bracket to the brake chamber. If it is not a light film, dried by accumulated road and brake dust then I mis-spoke.

[Jon Wehrenberg]

JIm,

Over the years I have broken 3 of the inner drive axle "nuts" with the threaded body and square head.

One was removed using the tool that grips it and it spun off the inner stud. The other two would not loosen so I welded a nut on the end (disconnecting the computers) and used my impact wrench to remove them. I have no idea why one will break, but they do on occasion. I did change all of them on the first coach, but one of the new ones broke so I now only replace one if it breaks.

My guess is that if someone applied them without using the proper torque that may have contributed to their failure. I cannot remember if any I installed failed nor if the ones that failed had been installed by someone else. On a couple of occasions such as when getting new tires I allowed someone to install my wheels. Nobody but me has removed or replaced a wheel on my current bus, and I also have not had to replace a broken stud on this bus so that might have something to do with the failure.

[JIM CHALOUPKA]

Two items I need help with;

The torque value for the nut holding the wheel stud into the wheel hub.

The torque value for lubricated lug nuts.

Thanks, JIM

[Jon Wehrenberg]

Lug nuts should not be lubricated. All torque values are for dry, clean threads.

[JIM CHALOUPKA]

Lug nuts should not be lubricated. All torque values are for dry, clean threads.

In the early days of POG there was posted a lubed torque value. It was less than the dry value.

I think part of the stud, nut problem is the siezing and galing of the dry threads. I could be wrong but that is what I believe. Dry might be the convention, but I think it is wrong.

I would like to know the engineering principle involved in specifying dry, other than out in the field it is unlikly that a down and dirty tire repair facility or other individual removing and installing wheels would have and know how to use the proper lube.

JIM

[JIM CHALOUPKA]

I removed the screws holding the brake drum to the hub and can not remove the brake drum.

What is the next step. I thought it would be loose???




JIM

[JIM KELLER]

Jim If you keep taking stuff apart on that Bus you won't get it together for Kerville !

[Kenneth Brewer]

I removed the screws holding the brake drum to the hub and can not remove the brake drum.

What is the next step. I thought it would be loose???


JIM

Two points for you to consider:

In my experience with the Bluebird, you will need to use a medium to heavyweight sledge hammer (around 20# head or so) to loosen the drum from the rotating studded flange it is bolted to. Several good raps may be necessary to break the rust. Keep in mind the drum is very heavy; do not drop a testicle trying to remove the drum laterally along the centerline to get it off. I had to do this with four drums (no tag).

It is possible that the shoes have cut a ring into the ID of the brake drum. You will have to back off the slef-adjusting brake cam/screw to bring the shoes in (toward the center) enough to clear the drum for removal.

[JIM CHALOUPKA]

Jim If you keep taking stuff apart on that Bus you won't get it together for Kerville !

Jim, this is not voluntary work.