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jelmore
06-08-2009, 11:34 AM
I'm going to have my tag tires replaced and have some questions. Since this won't be done at Prevost, I need to make sure I know something about what will be going on.

Lifting: I've read here and in the books that the tag should be lifted before lifting the bus from the front or drive axle. I'm not clear if this is the case if the bus is lifted from the frame. I would presume so. What if they want to lift from the tag axle, should it still be up? Or should they not lift from the tag?

Switching wheels: Are there any issues with moving the steer wheels and tires to the tag axle and moving the tag wheels with new tires to the steer, other than a good balance on the new tires?

Without asking, I would have guessed that the best procedure would be to set the brake, raise the tag and lift one side by the steer and drive axles, do that change and then do the other side.

Also, I'm pretty sure these are stud mounted wheels so the nut rotation is opposite on the left side. Did I get that right?

This isn't a bus shop doing the work, it's truck tire company. Just got to make sure I know what they're doing.

phorner
06-08-2009, 01:05 PM
I can confirm that the nut rotation is opposite on the left (drivers) side. As I recall, the studs were clearly marked.

Jon Wehrenberg
06-08-2009, 07:11 PM
Jim,

If the steers are worn evenly and there is no cupping I see no issues moving the wheels with tires to the tag positions. If the tires show any signs of uneven wear on my first bus as a result of bad advice I did what you are suggesting with tires that had slight cupping and in about 6000 miles they destroyed themselves with wear at the cupping right down to the steel cords.

Since that error I moved tires with uneven wear to the drives which means I had to move steers and tags to the drives involving breaking them down and remounting. Tires on the drives will eventually wear straight and even. My current tags came from the steers but since wear was even they are wearing OK.

I don't think there is a specific jacking sequence. It isn't like you are supporting the entire chassis. You are just raising the tire about a 1/2 inch off the ground and we certainly drive our buses over uneven campground roads which subject the suspension to far worse.

My only concern with tire shops is the guy with the 1" impact wrench usually drives the nuts home with no regard to the correct torque for aluminum wheels. If you mention the right tourque they usually tell you that is the way they do all the wheels. Prior to doing my own mounting of tires I would only allow the tire guy to snug them up and I would torque them using my torque wrench and the X-12.

jelmore
06-08-2009, 07:33 PM
Thanks Jon and Paul . . .

It's done and I only replaced one tag tire so I left it where it was. The other tag is a 13th week 05 tire so it still has some useful life and isn't showing any significant signs of age or wear. The tire shop manager, who had the open opportunity to sell me another new tire at over $800 said I didn't need it. The steers are in great shape. I showed the tire guy the lift points and started out with the tag up and he used a body jack point. Got the tire off but it couldn't come out from under the fender. So, dropped the tag and used a jack under the tag axle. All went well, including the instructions to torque to 450-500 ft. lbs.

A lesson learned with this tire . . . a year ago, I had replaced the tire on this tag wheel with a new one (I thought). All the steers and drives I had replaced a year before that. So this tag tire was a great price, $500, and I was happy. After several bus washings and tire detailings, I noticed sidewall separation and kept an eye on it. While on the road, while at Prevost, I told them I thought I had a warranty claim for a bad tire. They said check with a Michelin dealer. They said go back to the original store. So, months later we end up back at the same store, they checked the tire and found it to be a 99 tire!!! They made a mistake when they mounted what I thought was a new tire. The date code was mounted on the inside so I couldn't readily check it. Never even thought I should. The lesson, I guess, is to make sure the date code is on the outside sidewall and that the tire you buy is what you expect. Another case of me not even knowing what to look for or ask about.

Gary & Peggy Stevens
06-09-2009, 12:49 AM
What is the CORRECT amount of Torque on our wheels?

I watched as a tire guy screwed up one of my lugs, by NOT hand tighting the nut all the way down first before he put the power torque wrench on it. He just spun it completely off the threads.

I insisted they pull the wheel and replace the screwed up lug, which they did.

Now I know better ! :)

Gary S.

jelmore
06-09-2009, 08:47 AM
This is from the book (1999 chassis) . . .

3.2 Installation
1. Mount the wheel over studs, being careful not to damage stud threads.
2. Screw in the hex stud nuts (refer to Figure 2 for sequence) so that wheel will position itself concentrically with hub. This is important, otherwise wheel may be eccentric with hub and will not run straight. In this initial step, slightly tighten the nuts to correctly position the wheel.
3. Tighten stud nuts progressively as shown in Figure 2. The final tightening should be done with a torque wrench. Tighten stud nuts to 450 - 500 lbfft (610 - 680 Nm) for aluminum as well as steel wheel.
Caution: Insufficient mounting torque can result in damage to parts. Excessive mounting torque can cause studs to break and the wheel to crack in stud hole area.

Joe Cannarozzi
06-09-2009, 09:59 AM
I feel compelled to comment on this topic for a few reasons. I have mounted hundreds of tires, many here have voiced concerns about over tightening and up until very recently I have not had the opportunity to use an X-12 and actually see the perfect torque.

There are 2 cycles of the 1 inch impact, it is freewheeling and then it hammers.

When the nut spins up tight against the rim it then begins to hammer. On my impact if you stop right there and check torque it will be tighter than torque specs already at that point.

When I first discovered this I was amazed. Seemed unsafe but with the knowledge of knowing many here only tighten to torque specs and none have ever had a tire come loose that method is also proven. Sorry but I am not comfortable with my lug nuts like that. I assume it is absolutely safe but I have the experience of 20 years of changing tires and I've never lost one I have mounted and also never had any trouble with any that were too tight to remove.

I have NEVER and I mean NEVER seen a rim crack due to over tightening and I have seen some rims so tight on other trucks I have serviced that it took 4 or 5 hammering sequences to get the lugs loose.

I think if this is something you are interested in getting perfect without buying the X-12 they sell torque sticks, Orren posted them once, they will allow a 1 inch gun to get to the perfect toque every time and it is small and inexpensive, buy one and had it to the tire guy when you install.

I have a "rhythm" I use with my gun, after the gun gets the nut tight and it begins to "hammer" I count 2 onethousand and stop. That is probably closer to 800 to 1000ftlbs at that point, I have never had one too tight to remove or come loose and I will continue this habit. There IS ABSOLUTLY NO WAY I will crack one of my rims exercising this technique.

I have seen numerous rims cracked from being loose and I suppose you could crack a rim over tightening but I have never seen it.

Nothing like going to a POGers place to help them with their bus at their own garage outfitted with every tool known to man and then some, only to watch the owners manually install ALL the wheels and lugs by hand with the X-12 with a perfectly good 1in impact sitting on the floor in the corner:rolleyes:

Moral of the story: we should be way more concerned with loose rims than overtightened ones.

Jon Wehrenberg
06-09-2009, 02:49 PM
This may be a variation in impact wrenches.

I can set mine (an Ingersol Rand) at the lowest torque setting and after it stops freewheeling and starts hammering I can watch rotation of the socket alomst come to a standstill. If I check it with the torque wrench and the X-12 I may have to go a little further to get to the 500 ft. lbs. I have gotten to where I am able to guess pretty close on the torque but I admit to it being less than 100%.

I can do all ten nuts on a wheel and half may be undertorqued according to my wrench and the X-12, and the balance torqued just right or more than enough. I think I need a torque stick.

hobobimmer
06-09-2009, 08:43 PM
Nothing like going to a POGers place to help them with their bus at their own garage outfitted with every tool known to man and then some, only to watch the owners manually install ALL the wheels and lugs by hand with the X-12 with a perfectly good 1in impact sitting on the floor in the corner:rolleyes:

So you just sat and watched the owners do the specified torque settings? Are you going to tell us who it is? Inquiring minds want to know who would do such a silly thing.

Kind of reminds Deb of the time Jon Wehrenberg watched Deb use the X-12 to tighten all the lugs by herself, telling her it was important she knew how to do this. I think she had it figured out by the second lug. She's a quick learner.

To all my POG friends, I'll write in a month or so when I get back from cross-Canada motorcycle trip. I leave Wednesday morning 6/10/09.

Eric and Debbie Faires
Huntsville, TN
1992 Angola 40 foot

Joe Cannarozzi
06-09-2009, 08:48 PM
Be careful out there EriC

phorner
06-09-2009, 09:50 PM
Good luck with your trip, Eric.

Keep the shiny side up!!!:D