Community Forums

terry735001 · 10-21-2018, 12:21 PM

I have seen things like this happen when a new windshield is installed with RV body twist OR a windshield that slides in its rubber guides before when i worked at a RV shop .

You never want to do any kind on upgrade to the sway bar or airbag system as it adds stress to the windshield

bill2011 · 10-23-2018, 09:29 AM

Quote:

Originally Posted by brobox

Dave using your example.......

Exactly....doesn't mean the scales are off they just give a variance. The 500 lbs has to have zero point.

All I can go by on the DOT scales that I have been using , never a tire or tread wear problem airing to their weigh tickets for 16 years . Works for me.

We just had our Anthem 44B weighed and weigh front left 7,680, front right 8,748, mid left 7780, mid right 7560 rear left 5600, rear right 5060. We were 95% full fuel and full of water. We have a full freezer on front right but can't figure why over 1,000 lbs difference between right and left front. We dont seem to have enough heavy items on right (door side) to cause this. Are other owners of 44b finding the same? Any ideas as to likely cause?

brobox · 10-23-2018, 06:03 PM

Bill, I had the same issue on the RBQ except the drivers side. I contributed it to the 8 AGMs on that side. Adjusted the tire pressure and continued to drive it. All of my heavy items, tool box, freezer, etc were on the P/S so there was not much that could have been done about it.

bill2011 · 10-24-2018, 03:41 AM

Quote:

Originally Posted by brobox

Bill, I had the same issue on the RBQ except the drivers side. I contributed it to the 8 AGMs on that side. Adjusted the tire pressure and continued to drive it. All of my heavy items, tool box, freezer, etc were on the P/S so there was not much that could have been done about it.

Ahh. Could be the same issue. My AGM's are on the passenger side. I was thinking they might be far enough back that the weight was on the mid tires but maybe it's on the front. Thanks for that info.

Victory Blue · 10-24-2018, 06:43 AM

Quote:

Originally Posted by bill2011

Ahh. Could be the same issue. My AGM's are on the passenger side. I was thinking they might be far enough back that the weight was on the mid tires but maybe it's on the front. Thanks for that info.

The 17 Anthem batteries are in the middle of the coach right in front of the drive axle; so, toward the back. They shouldn’t be causing your weight imbalance issues like they did on previous year coaches.

DeeGee · 10-28-2018, 06:06 PM

OP here. I took the coach to a truck scale today. I had full fuel, full water, empty waste tanks, DW onboard, and normal basement stuff. Basically, as we travel except that there is no clothing or food onboard, the refrigerator is empty, etc.

Here is the last weight we had, FYI:

.........Total........Rating..Diff
Front....18860 (+225)..17000..2085
Drive....16360.........20000..(3640)
Tag.......9260.........12000..(2740)
Totals...44705.........49000..(4925)

Here is what we had today:

.........Total........Rating..Diff
Front....16890.........17000...(110)
Drive....15160.........20000..(4840)
Tag......10400.........12000..(1600)
Totals...42450.........49000..(6550)

Bearing in mind that the earlier weight was with 50% water, this is strange. There is no way that we carry more than 2500 pounds of food and clothing.

Not even close. Even factoring in the booze.

It's like the guy with one watch knows what time it is, add a second and he is never sure again.

If I believe this, and I suspect that it is the most accurate weight so far, I can barely add anything to the coach interior without going over on the front axle.

Remember that with an adjustable tag pressure, every 100 pounds removed from the tag removes 15 from the front axle and adds 115 to the drive. So, if I removed 3000 from the tag, I would have:

.........Total........Rating..Diff
Front....16440.........17000...(560)
Drive....19810.........20000...(190)
Tag.......7400.........12000..(4600)
Totals...42450.........49000..(6550)

That's a bit to close to the limit on the drive, and I don't like the drive/tag ratio, so let's calculate again for 2500 pounds off the tag:

.........Total........Rating..Diff
Front....16515.........17000...(485)
Drive....19235.........20000...(765)
Tag.......7900.........12000..(4100)
Totals...42450.........49000..(6550)

Somewhat better... I definitely don't like how high these weights are.

MatthewChase · 10-28-2018, 07:36 PM

I don't have a tag but my experience is that mine was originally built at capacity, empty. This means if I am full water and fuel, I'm going overweight on my front axle by 800lbs. I travel with half fuel which is annoying stopping more often and that gets me closer. I have stripped out tile floors, and washing machine and so on and it is still 600lbs over on the front. Short of removing the generator (not going to happen)there is nothing else to remove. i hope a weigh in will not notice an axle overweight but total gvwr which I am within.

I don't like how they build these with all this storage but the second you store anything, you are overweight. Manufacturers, install larger axles!!!

DeeGee · 10-28-2018, 10:25 PM

I notice that the overall weights from today are similar to what I had at Quartzsite in January. Then, I had food and clothing onboard, but half a tank of water. Today, I had full water and no gear.

As weighed at Quartzsite in January.
.........Total........Rating..Diff
Front....16800 (+225)..17000..25
Drive....14925.........20000..(5075)
Tag......10475.........12000..(1525)
Totals...42200.........49000..(6800)

Today:
.........Total........Rating..Diff
Front....16890.........17000...(110)
Drive....15160.........20000..(4840)
Tag......10400.........12000..(1600)
Totals...42450.........49000..(6550)

Loren B. · 10-28-2018, 10:54 PM

Quote:

Originally Posted by DeeGee

Don had a recent thread discussing his addition of a pressure regulator to adjust the weight distributions between axles. It looks like I need that a lot, or something more.

I had the coach weighed at Quartzsite in January and found that the left/right imbalance was 2000 pounds on the front axle, and with full fuel I was slightly overweight on that axle. I eventually found a shop that diagnosed a broken air valve, which would cause the left side to have too much air, increasing the weight on the right

I'm not a MH guy so I am assuming (yes, I know what that means) that you are discussing the air pressure in the suspension at the various wheel positions, right?

If this is so, you should know that changing the air pressure at any point in the suspension will have a negligible effect on the weight carried by that axle/wheel. It's difficult to post the diagrams that would demonstrate this here so I'm not going to try, but you can ask any engineering student who is beyond his sophomore year to draw the appropriate free-body diagrams to show you.

This, of course, is not saying that dropping another axle (e.g. tag axle) with two or four more tires won't affect the weight on all the others. It will. I'm just saying that changing the air pressure at, say, the left-front wheel position won't change the weight on that wheel much more than changing the pressure in the tire will.

If I misunderstand what is reported here maybe someone can enlighten me. I notice that most of this thread has become a discussion about the accuracy of various scales. Regarding that, it matters that the scale (and any approach and departure driveway) all be level. Not just flat; they must be level. (Walls are flat but not level.) It doesn't matter if your vehicle is level as long as the scale is. (Your vehicle can lean to one side and the weights will still be accurate, but not if one axle is on an approach slab that isn't level with the scale.)

-- Loren

DeeGee · 10-29-2018, 12:39 AM

The tag air bag can most definitely affect the weight on the axles. An overinflated bag pushes up on the rear of the chassis. The drive axle serves as a fulcrum, and so that upward pressure is converted to a downward pressure on the front, increasing the weight on that axle. Reducing the tag pressure relieves this load, and both the tag and front carry less weight. The drive axle picks up the load. That amount of change can be calculated knowing the length of the lever arms.

See the thread so that's why my front axle is so heavy for a discussion, complete with experimental data.

What I need to do is what Don did; reduce the pressure in the tag lighten it and the front.

Loren B. · 10-29-2018, 08:28 AM

Quote:

Originally Posted by Loren B.

This, of course, is not saying that dropping another axle (e.g. tag axle) with two or four more tires won't affect the weight on all the others. It will. I'm just saying that changing the air pressure at, say, the left-front wheel position won't change the weight on that wheel much more than changing the pressure in the tire will.

DeeGee,

I agree that dropping a tag axle or changing the suspension pressure on one will dramatically change the weights carried by the other axles. I thought that your original post was stating that changing the suspension pressure on one side (left or right) will change the weight carried by a given wheel significantly. If that's not what you were saying then I misunderstood.

It's still true that changing suspension pressure on one side (left or right) of the vehicle will just cause it to lean slightly right or left. The only change to the weights carried by wheels in that case would be from the extremely slight lateral movement of the CG (Center of Gravity) towards one side or the other.

-- Loren

Gordon Dewald · 10-29-2018, 08:46 AM

Quote:

Originally Posted by Gary.Jones

Bryan

The platforms take the coach to exactly the same distance off the pavement as the scales take the coach. The platforms are there to keep the coach "level"

Chuck: I really doubt that DOT scales are all that exactly accurate either. When you are dealing with a fully loaded semi, a couple hundred pounds one way or the other is really not an issue. I would like someone who knows the facts to indicate within what bandwidth of accuracy state or DOT scales must be within and how frequently they are calibrated.

Jack: I really wonder how any scale is calibrated such as the ones at NIRVC and the 4-Corner weight type portable scales. Can we expect the weights to be 100% accurate.. I doubt it.

Now, Dave, your differences are enough to blow right on past my questions over technical accuracy, and I think you are right to keep following the string until you get the answer.

Gary

When I certified scales the manual read that the weight must be within one gradation of the scale. That was with a minimum of 2000 lbs of test weights.

During certification the weights were placed at various locations on the deck and the weight had to be within on gradation at every location.

At each location the weights were placed an additional weight equal to the scale gradation (sensitivity test) was placed on the scale and the scale must show the extra weight. (if the gradation was 10 lbs the scale must show 1990 lbs to 2010 lbs and when the a 10 lb weight was added must show the 10 lbs.)

This was done on an empty scale and than a loaded truck was driven on equal or greater than the maximum load and the test weights including sensitivity test were repeated.

When using a scale ensure the deck is clean and there is no debris between the deck and the surrounding frame. A pinch point can make the scale give really confusing weights.

vito.a · 10-29-2018, 09:28 AM

DeeGee, what does Entegra say about your front axle loading?
Are all Anthem front axles this way?

Our coach comes with an air pressure regulator that we use to load/unload the tag and thus control the front axle weight. That may be a solution for you.
From our manual:
Tag Axle Motorhome (Roadmaster Chassis):
Motorhomes equipped with a tag axle will require adjustment to the air pressure regulator for the tag axle to maintain proper axle weight distribution ratios. The adjustable regulator and gauge package are located in the engine compartment on the driver side. The regulator is designed to control the amount of air pressure in the tag axle air bags. Increasing the regulator pressure gauge reading will increase the amount of air pressure in the tag axle air bags, and downward force of the tag axle. Applying downward force to the tag axle decreases the weight carried by the drive axle.

Our manual also recommends the six point weight process (individually weighing each of the six tire groups).

LargeMarge · 10-29-2018, 11:11 AM

Huh.

To weigh our rig, we visit highway weigh-stations while they are closed. We weigh each axle, then weigh each side, then weigh each axle-end.

A ballet.

Using this method for a chum with tire wear issues, we determined her left front tire was overloaded by double its rating, a result of all her batteries plus fuel and water and pantry designed behind the driver seat.

She is a big == buffet professional == woman, so we weighed her rig with her in the driver seat. Zing!

Nothing to do except rebuild the cabinets in a different location and partial-fill her tanks.

I have an opinion on this:
The engineers and designers of her rig should be lined up against a wall...