4 corner weight ? inflation

[jimbo2013]

Just did a weight.

Full water tank, 1/2 tank fuel,

both f/8400 R/15,100

Front R/3700 L/4800

Rear R/7660 L/7160

I have 255/70R 22.5 tires

The chart says <4190 80lbs 4895 100lbs on single

<7940 80lbs

Right now I have 95 front and 100 rear.

Is a difference left to right normal in these MH's?

What do you think I should do and air up at?

[ahicks]

I'm no pro when it comes to chassis stuff, but my first thought is regarding the ride height adjusters? If one of them is way off, you might get readings like the ones you have?

[D Lindy]

Yes you'll have a difference in weight from left to right in both front and rear 4 corner weighs. Factors being, Slide size, location; fuel tank location; fresh water tank location; fridge location; what you have loaded in the basement and where. You might be able to even out the weights a little you looking at what's in the basement and where, and move the heavy items to the side with less weight on the tire.

[BFlinn181]

Were the corner weights measured separately from the front and rear weights? When you add up the L+R for the rear, it's 380 lbs different than the combined. Front is different by 100 lbs. What does the scale operator say about the differences? If you had to run one side up onto the scale for side measure, perhaps the lean shifted liquids enough for the difference??

[luvlabs]

If you have Michelin tires...

You inflate all tires to the same pressure as the heaviest tire. If you use the Michelin tire chart for the axle weight, you would inflate the fronts to 85 lbs per tire. This also holds true for the single, heaviest side.

Your rears are too high at 100 lbs. You take the heaviest side and use the column in the tire inflation chart for dual tires (or use the total axle weight). The Michelin chart for that size tire is 80 lbs per tire for the rear based on total axle weight or the individual side weight.

You should consult the tire charts for your exact tire size and make to do this right. Tire inflation pressures make a big difference in ride quality and handling so you should try and get these correct.

You will get side to side differences but you would have to contact other owners to see if your numbers are within range.

[DGShaffer]

As stated above, you need to inflate them to the manufacturers recommendations for the size and type tire. Personally I run 85 in the rear and 75 in the front. I had mine weighed on an in-floor scale so there wasn't any lean but that was a good point.

[targaboat]

Let's keep this thread going for a while since Spring is a ways off. You must have all of the weights equal within 50 pounds otherwise you will have instant disaster and need to go adjust something. However, a few things for thought>

How precise are the scales with all of the mud and weather involved?
How much does a little side lead affect measurements\
How much does all of the weight on one corner of edge of the scale affect the reading
Does the operator wait for the needle to settle
When was the scale last serviced
How much traffic does the scale have
How does ambient temperature affect readings
Is the scale new technology or 70 years old with new technology readouts

Take this list to the operator and watch the expression on his face. Let us know the results.

Seriously, although the scale operators will not admit it, probably the accuracy of the precision of the common scale results in readings which are no better than 400 pounds to begin with. Then there are all of the variables in the RV which occur from day to day.

The scale is designed to weight about 80,000 lbs and 400 pounds is .5%

[D Lindy]

Targaboat; Why do you say you MUST have all of the weights equal within 50 lbs. otherwise you'll have instant disaster????? It will be IMPOSIBLE to get left front and right front within 50 lbs of each other just based on having a passenger in the front seat sometimes and sometimes not. What is your instant disaster that will be incurred???

[gemini5362]

I also am curious about the instant disaster. Lets look at some perspective here. 2 people in a small car the wife in the passenger sides weighs 100 pounds the huge husband I the drivers side weighs 350. That is a weight difference in a car that could weigh less than a ton. Is that a recipe for disaster ? And if more than 50 pounds weight difference in a 30 or 40 thousand pound vehicle is a recipe for disaster the small car difference I am discussing as a hypothetical is so dangerous as to be unbelievable.

I personally think there is way too much discussion about balancing weights. There are hundreds of thousands of motor homes out on the road and I would imagine only a fraction of the people that own them worry about it. I don't. If I go for a ride with my granddaughter I weigh about 250 she weighs about 50 that is a 200 pound difference right to left. Do I need to go and quickly adjust things in the cargo compartment or add sand bags on her side. No I don't The ride levelers in my suspension add more air to my side to compensate for any difference.

It is a good idea to know what amount of weight your axles will hold if you are going on a long trip or fulltiming it might be a good idea to get loaded up and go on a scale to make sure you are not overloading the axles or the suspension. The constantly weighing 4 tires separately is a fun thing to do for a hobby I guess but is it really that necessary

[DGShaffer]

I'm thinking Targaboat was being sarcastic?

[2 Stroker]

I had my coach weighted at the FMCA Rally in Albany,Or (4 corner wt) and I'm over wt in the rear by 1150lbs and under in the front by 730lbs. In January I got a new set of Michelin 295/80R22.5 XZA2 with a max PSI of 120lbs. With a combined wt of 33,620lbs FR 6,405lbs-FL 6,065lbs RR 10,195lbs-LR 10,955lbs I have to run 105 PSI in the front and 100 PSI in the rear. This is the only way to get a true wt reading and know what PSI to run, money well spent. Must be the new steel and copper radiator on the LR and not the way the wife packed the coach.
2 stroker

[Wayne M]

Originally Posted by jimbo2013

Just did a weight.
Full water tank, 1/2 tank fuel,
both f/8400 R/15,100
Front R/3700 L/4800
Rear R/7660 L/7160
I have 255/70R 22.5 tires
The chart says <4190 80lbs 4895 100lbs on single
<7940 80lbs
Right now I have 95 front and 100 rear.
Is a difference left to right normal in these MH's?
What do you think I should do and air up at?

Yes, there will be a difference and it is wise to try and distribute the load. You are 1000 pounds heaver on the left side. That is a considerable difference. Take a look at what you have in your forward bays and see if you can redistribute some of the weight.

In any case the air pressure you use will be the same across all tires on the same axle. In your situation you would inflate both front tires as if they were 4800 pounds. So both tires would be inflated as a minimum at 100 psi.

Now consider that 100 psi support 4895 pounds and you already weigh 4800 pounds on that tire, that leaves only 95 pounds of "fudge factor." If DW buys some souvenirs you could exceed the capacity of the air carrying the load. So why not put in 105 psi and be able to go up to the next level. Also, by adding 105 psi if there are any temperature changes or altitude changes you would still be within the load carrying limit of the air in the tire.

Just sayin'.

[Steve Ownby]

Originally Posted by jimbo2013

Just did a weight. Full water tank, 1/2 tank fuel, both f/8400 R/15,100 Front R/3700 L/4800 Rear R/7660 L/7160 I have 255/70R 22.5 tires The chart says <4190 80lbs 4895 100lbs on single <7940 80lbs Right now I have 95 front and 100 rear. Is a difference left to right normal in these MH's? What do you think I should do and air up at?

Air suspensions are great while the coach is in motion but they can give less than accurate weights in a static condition. The is caused by the fact that there are 3 ride height valves and 4 corners to the coach. If you have a chance to weigh again try this:

1. Pull directly in line with the scale with your wheels straight.
2. Cut the engine and dump air completely.
3. Start engine and allow to come to ride height.
4. Pull straight onto the scale.
If getting the corner weights require more than one pass, repeat this for each pass.

I thought this might be some of your side to side weight imbalance because your heavy corners are diagonal.

[jimbo2013]

Well as of now before I did the scale weights I have 95 in the fronts and 100 in the rears.

The engine was running all the time on the scales, so full air pressure

It drove ok on my first 120 mile trip, so can the tires be that far off?

In looking at the coach on flat pavement it sits very level to the eye, the tires don't appear squat on one side vs the other.

With the variation I stated above wouldn't you think I would see a difference?

All confusing, I can do a reweigh it's only $12, but don't understand why dumping the air would matter, by I can try it.