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thenewkid64 01-26-2004 09:10 PM

Bearing adjustment?
Here is my latest conundrum.

I have a wheel vibration that comes and goes. It is coming form the pass side front wheel. The tire has begun to cup a wee bit on the outside edge. The motor home tracks straight, does not pull as far as I can tell. I am in the market for a couple of new tires but these are less than 3 yrs old. This started in West Texas on the way home and has progressively gotten worse. It started after a section of rough road, so I assumed I threw a weight. But the cupping is even around the tire.

Is this a symptom of a loose wheel bearing?

Greasing the front suspension has not made a difference. I have a properly rated jack, I don't mind getting greasy. I used to do the drum front brakes on my 64 "cuda a couple of times a year, so I know what I am looking at when I pull the dust cap, right? Is this a DIY fix?

I am thinking jack it up, pop the dust cap, pull the pin and tighten the nut one or two hole and reassemble. :confused:

I welcome your advice :D

markdoane 01-26-2004 09:21 PM

Bearing Adjustment
Here's the correct method for preloading wheel bearings. Seems extreme, but here it is

thenewkid64 01-26-2004 09:34 PM

I would assume that based on this I just do the steps? Now all I need is a torque wrench that goes to 200 LBS and can take the right size socket!

Has anyone popped the dust cap on their MH? Am I right in assuming it is a standard type configuration?

74Argosy24MH 01-27-2004 06:17 AM

Standard configuration, but bearing preload is 65-90 lbs, back of 1/6 to 1/4 turn or the nearest hole. End play is .001-.007.

After you do this and get tires have the front end aligned, that is probably where the cupping (and vibration) is coming from.


87MH 01-27-2004 06:27 AM

I agree with John, check the alignment.

The trick is, find a shop that is properly equipped and HAS EXPERIENCE with the P-30 chassis.

There is a Freightliner shop only a couple of miles from the house, but they won't touch motorhomes.

The premier P-30 alignment shop in Houston is about 40 miles from me, but it is worth the drive.

If you are going to change out or rotate the tires, do that before you take it to the alignment shop.

Please keep the rest of us posted as to the results.

Rick Alston 01-27-2004 06:55 AM

It may not be the wheel bearing
I am not motorhome owner, but I assume your motorhome has the same steering arrangement as an automobile, so you ought to check the ball joints for excessive wear and tear.

I found this problem on my tow vehicle after towing a 31' A/S for a number of years and I suspect the ball joints take a beating because of the added side loads caused by the long coach. This may apply to motorhomes, too, as one tends to "steer often" to compensate for the effect that wind has on directional control.

As far as the wheel bearings are concerned, you will hear a scraping sound once they begin to deteriorate-they get noisey. Generally speaking, they won't go bad unless the grease goes away - look for evidence of leakage around the hub. If the previous wheel bearing job was done correctly, the lock nut was tighened down to the proper torque specification and a cotter pin inserted to keep it from loosening so the bearing would remain properly seated.

The fact that your tire wear - cupping- is consistent, makes me first think of the ball joints. I am also suspicious of lube technicians that lubricate ball joints when the wheel is on the ground. A proper way to lube ball joints is to take off the load of the front end before lubing to allow better distribution of the product.

wb13798 01-27-2004 07:24 AM

check the lower ball joint . that was a problem with my rig. but also make sure you have a good set of shocks. and tire is balanced.
dont know if you have a tire dealer that will true the tire . if you do get the tire trued balanced and put it on the rear.
not all alignment shops can align the p-30 chassis . the chevy dealer here will not tuch one. reffers you to a local tire dealer.
something about the lift they use, will not lift a p-30 correctly. also had a tire dealer that services large trucks try and couldnt get the rig on the lift correctly. im sure there is a better explainiation but that is what they told me.
if it is lower ball joints dont pay the $200 dollars that napa wants for their product go to auto zone $106 for the same item different label.
best thing to do is find an alignment shop and have them check the front end out. the shop i used didnt charge anything to tell me what was in need of repair. and gave me a cost estimate .
wasnt happy when i returned a week later for and alignment .

Ken J 01-27-2004 08:55 AM

One other thing to consider is your shocks - they do get weak and can cause cupping

Ken J.

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