replacement air springs

[Joe Cannarozzi]

If it were my bus I would first swap the steer tire with a drive tire. Balance it and replace the front shocks with gas or koni. Do an alignment.

The wheel bearings are checked by removing the hub cap and removing the jam nut and checking the inner nut for correct tightness.

That price for new bearings Prevo gave you is outrageous IMO. The king-pin estimate may be more in line.

If you need to shim up the thruster bearing you may as well replace the kingpins cause you will have to all but pull them to add the washer. I do not think that is the cause for your unusuall tire wear.

A slight misalignment with a slight tire imbalance and tired shocks could have worn that tire bad. That is my opinion.

These buses are built like tanks the components they use are heavier duty than trucks and they are carrying less weight.

None of us should ever need king pins or wheel bearings unless something very drasticly wrong went on.

[Jon Wehrenberg]

I'm 100% with Joe on this one.

To avoid having to repolish a wheel break down the tires when swapping from the steer to the drive. When the wheel is off is a good time to carefully inspect the steer axle components for wear or adjustment issues, but unless this coach has high mileage or has been poorly maintained (as in failure to lube the king pins regularly) I doubt if any problems will be found. Some movement is normal and the Prevost service manual provides the measurement and method. It is available on line.

http://prevostparts.volvo.com/techni.../en/wiring.asp

$1500 to replace bearings is bogus. First these bearings are very robust, and second I cannot believe they are anywhere close to that price, even considering replacement will require new hub seals.

[Darrell McCarley]

JOE and JON...........Thanks for your input. I will go to a tire store this week to have the steer and drive switched. I will also check the hub with the tire removed. I have the bus serviced at Prevost DFW and Prevost Mira Loma ever 10,000 miles. I would think the king pins would be part of the lube service. Thanks again for your advice.

[Kenneth Brewer]

If you have the bearing number off the bearing, you can get a price from any bearing supply shop. All bearings have the bearing number than is used internationally. If the bearing (as long as it was 'manufactured') has a/the number it wouldn't matter if it was on a Russian farm tractor or military tank in Somalia, you can easily order it. I would be surprised if you tell me me it is more than a couple hundred dollars. I would think the $1500 includes labor (it would be ridiculous, even so).

I have replaced steer wheel and drive axle bearings on a Foretravel and a Bluebird, both, and it isn't a big deal at all except for taking drums off (if you don't have disc brakes) without dropping a testicle or two. Axle nut tightness is critical, however. But that is easy too. I can lead you through the procedure if you like.

Some easy things to check: are the tires cupped, or are the rims bent (determined by lateral run-out, which you should be able to do visually with a fixed pointer at the rim radius), or is it possible you have radial run-out which can happen if the bead slipped. It requires you have the wheel/tire off the ground and spin it.

[Darrell McCarley]

KEN......Using the good information from you, Joe and Jon, I will try to identify my problem. If I need bearings or king pins, I will talk to Prevost DFW about a little price reduction. They are good people to work with so I am sure we can work out a reasonable price. I would like to perform the work myself but I think it requires too much knowledge and labor for a shade tree mechanic like me.

[gmcbuffalo]

Guys if the tire is worn out in one spot would this not mean that something that is turn with the tire (hub, wheel or tire) is causing the wear? Seems like a king pin, axle bearing or shock which are independent of the tire would not cause a problem in one specific area of the tire.
GregM

[Darrell McCarley]

Greg......The Michelin XZ2 has 5 or 6 groves of thread. The 1 ft of wear is on the thread in the middle of the tire. I cannot understand why there is no wear on either thread on each side of the middle thread. I have never seen a tire ware in this manner. If it is out of alignment or low on air pressure, I would think it would wear on the edges. Over inflated, it should wear in the middle all the way around the tire. Because of this unusual wear pattern, I thought the tire was defective with a soft rubber spot.

[Ray Davis]

Darrell,

Are you saying that the damage is a 1 foot strip, one inch wide, i.e. it doesn't go round the entire tire?

If so, I gotta agree with Greg. I don't see how anything external is going to cause something like that limited to a 12x1 inch area of the tire.

Ray

[Jon Wehrenberg]

Darrell,

Go to Prevost armed with info and don't let them BS you about labor times. Stay close and write down what they do and when they do it. They will realize they cannot fluff up the bill. The info Ken gave about bearing numbers is true. They are generic and cheap. I doubt if you even need them.

As to labor I hope Joe confirmes this, but I can have the bearings out of the front hub in 1 hour from when I start working on the bus. Add 1.5 hours to put it back together and an additional hour to check the kingpins and deal with the hub seal and clean things up and you should be done. The reality is pulling the hub nut with the wheel in place, examining the outer bearing and race to verify the bearing is OK is likely all you need to have done. There is no reason why the inner bearing will be bad if the outer one is OK. Less than an hour for that.

If the kingpins were lubed as you say I have serious doubts if they are bad. If Prevost insists they are, make sure you keep them and post pictures. Bad kingpins will have very evident wear.

[Orren Zook]

King pin replacement (with metal bushings) should typically take 4-5 hours labor plus parts, a significantly lower price than what was quoted in an earlier post.