replacement air springs

[Darrell McCarley]

JOE.......The movement was up and down when he placed a crow bar under the wheel and pulled upward. I had the shocks replaced 30,000 miles ago (3yrs) at Prevost DFW. How would you check for loose wheel bearings without removing the hub assy? Would the wheel have movement, in and out, side to side, or noise from spinning the wheels while on jack stands? I called Prevost DFW today for a price quote. Wheel bearings $1500, King Pins $1800. With your help, I would like to know my options if I go Prevost for repair. Thanks Joe for your input.

[Joe Cannarozzi]

Up and down 1/16 is neglidgable play in the shims between the spindle and axle for the thruster bearing.

More questions

How are the front wheels balanced and how does it preform. Are you noticing anything at the wheel that has recently changed for the worse?

[Darrell McCarley]

JOE......I have heard about shims for the front suspension but I do not know how they work. Would shims take the up and down slack out of the wheels? Is it a major task to replace or add shims?

[Darrell McCarley]

JOE......The front wheels are balanced with a smooth ride. I have noticed a slight vibration at 20-30mph. Vibration goes away with increase of speed. Are we starting to think wheel bearing?

[Darrell McCarley]

JOE....I can feel the slight vibration in the steering wheel, not in the ride.

[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.