| Author |
Message |
Brian Elfert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 7:50 pm: | |
I ended up purchasing 8 Firestone FS590 Plus tires for my coach. They cost right at $350 each mounted. The Kelly tires I was quoted at $259 each mounted turned out to be some off brand supposedly made by Kelly.
The tires on the coach were all total junk. The tire dealer couldn't keep any for casings.
My two tag tires both are worn a fair amount after my 1600 mile trip. The tag axle had at least one and maybe two 22.5 wheels on it at the dealer. The dealer put 24.5 wheels on the tag to match the rest of the wheels.
Should the air bag pressure on the tag axle have been adjusted to accomodate for the larger wheels? The coach calls for 24.5 wheels as standard. I suppose I should crack open the maintainance manual to see what it says.
Brian Elfert |
bruce knee (Bruceknee)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 8:02 pm: | |
there is only about 3/4" in dia. difference between 12-225 and 11-245, worry about something else. |
Brian Elfert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 8:09 pm: | |
Well, something is causing a lot of wear on the two tag tires. The drive tires still look like new as they should. but the tag tires both have a lot of wear and almost look like they are cupping.
Any ideas what would cause this on the tags if not the air bags? All 8 tires were replaced Friday before I drove 1600 miles home.
Brian Elfert |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 8:14 pm: | |
If 1600 miles has cupped or worn your tags - you have problems more critical than your bag PSI - FWIW |
bruce knee (Bruceknee)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 8:18 pm: | |
does the tag steer? |
Greg Roberts (Gregeagle20)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 8:25 pm: | |
Low tag pressure and bouncing to cause the cupping? Just a guess. |
Brian Elfert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 9:19 pm: | |
I was just out looking at the bus and was looking at the tags. No steering on the tag even though it is 43 foot.
There is a air pressure regulator with gauge just for the tags. The pressure is reading right according to the book and the labels.
Brian Elfert |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 9:28 pm: | |
Brand new $350 tires on the tags? (whew)
Worn radius rod bushings can cause cupping, as well as
too little pressure on the tags. Did you make sure any tag
pressure valve that may be present, is operative?
On the MCIs, the air pressure can be released to lift (jack up
and suspend) the tags. The tags will look like they're on the
ground,with the valve open, but there won't be any weight
on them.
Before you go too far, keep in mind that the tags will wear
real quick if you're making a lot of tight turns, They drag
sideways as you turn..... It's the reason no company puts
new tires on a tag.. |
Ed (Ednj)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 9:38 pm: | |
John said-Worn radius rod bushings can cause cupping, as well as
too little pressure on the tags. Did you make sure any tag
pressure valve that may be present, is operative?
>
Unload the tags, and with a long bar (like a shale breaker)place a bar against the out side drive and behind the tag and see if you can move the tag tire in and out. |
Dave Wilson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 10:55 pm: | |
Dont panic how did it ride home after the new mocasins installed?If the dealer owned the coach you can be sure the rubber on it was just good enough to get you out of the yard legally.If she ran along nice and smooth now vibrations or shimmies iwouldnt start messing with the pressure going to the tags.Very rarely would you put new on the tag like John says that is where i run off my old sterring tires,if there cupped they will give a crappy ride.Then pull off and look for good used around the yard. |
Jon W.
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 7:36 am: | |
I am not sure of the underlying cause, but from personal experience I can tell you that out of balance tires on the tag will eat themselves up very quickly, and in about 2000 miles I had used but good tires (no cupping or worn out tread) exhibit such severe cupping they exposed the steel.
Since I have been using Equal or using balanced tires on the tag the problem has never been repeated.
I would put the cupped tires on the drive to straighten them out. They will destroy themselves if left on the tag. |
J.C.B. (Eagle)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 8:01 am: | |
Have the alignment checked on the tag. |
J.C.B. (Eagle)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 8:02 am: | |
Have the alignment checked on the tag. |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 12:12 pm: | |
Brian - with the coach sitting straight on level ground - steers perfectly straight - measure:
1) distance from center of driver steer hub to center of driver drive hub
2) distance from center of driver steer hub to center of driver tag hub
3) distance from center of driver drive hub to center of driver tag hub
4) REPEAT 1-3 ON PASSENGER SIDE
Just to see if anything becomes self-evident?
HTH |
truthhunter@shaw.ca
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 1:16 pm: | |
HTH , that is a good check if it can be done accurately (easy if you have electronic alignment heads, which I don't) Any suggestions on how to ensure the front wheels are dead strait (maybe one could jig a laser pointer on each front hub, as that was all those early electronic alignment hubs were) |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 1:32 pm: | |
HTH - I'm actualy Niles (HTH = Hope This Helps)
If you can scrounge up say a 30+ foot section of straight aluminum header or equivalent (wheel base distance) - elevate to hub centers running from stear to tags - using a T-square measure from either side of outer hub (or wheel) to header and adjust till equi-distant - you should be able to line it up close enough for government work - if you have a laser you can mount it to steer hub (wheel) - I'm just guessing that any misalignment of any of the above that could cause that much damage for highway 1600 mile drive will probably be evident and signal that it should be brought to an alignment shop or rule that part of the equation out - FWIW (For What Its Worth) - Niles |
truthhunter@shaw.ca
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 1:52 pm: | |
Yes thanks Niles , that does give me some improvised ideas. Not being sure what bus is being listed above, if it was MCI with independent tags, one must check that the bearings in the arm are tight as well as the wheel bearings. It is very odd that both sides of the tag shredded so quick (unless it is a solid tag axle) so something is obviously very wrong here, weather it is a slow speed tag brake lock up, extremly light pressure on the tag, alignment or both tires are so wildly out of balance to cause such quick cupping. On my MC 8 , I am not sure what the cause is yet as the only thing I noticed was the cross member that braces the independent tag axles has a big dent in it (from hitting something I guess)and I would suspect that has a lot to do with the rapid cupping (maybe why it was sell time) |
Brian Elfert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 2:55 pm: | |
This is a Dina bus. The tag axles are independent.
The next time I start the bus I will check to be sure the tag axle air regulator is really set to 43 PSI as it should be.
Brian Elfert |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 8:20 pm: | |
With the Stecco dump body I used, we set the gauges for
the load weight being carried. I.E.: We'd load up, drive to
a level, solid area, set the pressure, drive forward 20' and
set it again.
With the tags, make sure you're on level, solid pavement,
and make sure the tire pressure is what's called for.
JonW made some good points about tire balance. It's worth
looking into, before spending time and cash on repairs that
could otherwise wait.. |
Brian Elfert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 9:16 pm: | |
Only the steer tires were balanced. The tire dealer recommended against balancing the rest.
Dina is very specific about setting the tag axle pressure at 43 PSI. They don't say anything about varying it.
I'm planning to take the bus out tomorrow for a quick spin and I'll see what the pressure is set to.
Brian Elfert |
truthhunter@shaw.ca
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 15, 2006 - 12:15 am: | |
If it is like older MCI tags , make sure the air is actually getting to the bags at that 43 psi as MC9J said (or someone) $Mine has 2 manual dump valves in the front of the small A/C compressor door just behind the right tag to shut the air off and dump it for jacking the tag or if you get high centered at a stop long enough for the leveling valves to adjust the height (happened in a icy car wash, all the drives would do is spin until I dumped the tag air)$. "If you have a electric tag unlaod switch for use from the drives station "on the left arm rest consol on MC 8 or 9, " there could be a problem there too amongst the dump solenoids and the low pressure regulator for 50% dump load (so don't just poke the tag bags with your finger and guess it is 45 psi when it could be 15 or 20 psi), as when it is unloaded for preventing getting stuck or backing up in the soft or snow (at low speeds only), the tag pressure is reduced to 50% or so. That could make your tags lock up on a heavy slow speed brake application and skid the tires making a cup like flat spot on both tires very quickly, like on sandy pavement or slightly wet/greasy conditions were raod static friction is reduced ". $I have had something like this happen to a pup trailer hauling freight, years ago with brake lock-up imbalance and again with bag pressure loading problem on a different pup $. Just my guess here as I have no real experience with this system MCI tag system other than what I mentiioned and I guess as possible from looking at the system and of course all every one else has mentioned including no sloppiness in any suspension components on any axle or alignment problems, then you may need to start guessing on the air brake application pressures and confirm they are all withing limits and the brake components are the specified sizes (like if something was just changed to get it sold with mix matched parts by the shop apprentice while his "journeyman was out to lunch", maybe even done with used parts, so look for bolts that have been changed recently not just new parts .
Most of all try to share what you have learned and not learned with the rest of the board when it is all done and you have time. |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 15, 2006 - 1:12 am: | |
not ballancing anythng but the steers is a truck thing.......and probably makes no difference at all on a truck.
A BUS IS NOT A TRUCK...ballance them all |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 15, 2006 - 4:06 pm: | |
Sounds like the jerk owes you a new set of skins |
truthhunter@shaw.ca
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 17, 2006 - 2:05 pm: | |
ah caveat "educatuim" emptor "Mcspensive"; but always worth the price when it is about bus conversions! |