Community Forums

chunker · 04-07-2016, 06:29 AM

Weighed the coach at the local Flying J with the following results. Nearly full fuel, almost empty fresh water and empty holding tanks. Not very much loaded as far as normal travel stuff, no food, clothes, etc but all the fixed kitchen gear and basement with the normal boards, grill etc. The refrigerator is on the right side and empty.

Axel weights are GARW front 14320, rear 20000, GVWR 34200. I couldn't do a real 4 corner weigh so I was able to weigh the left side, then go back on and weigh the whole coach. 1st weigh left front 5280, left rear 9320, GW 14760, second weigh front 10600, rear 19680, GW 30460. Doing the math the RF is 5320 and RR 10360. Front weight differences are pretty close 40 pounds but the rear is 1040 heavier on the right.

I obviously have a lot of margin on the front but would also like to get the left/right balance closer. Looking at the loading, I'm not sure what I can load more left and less right when considering weights. I presume that the liquids are centered L/R on the coach so adding water and fuel load doesn't affect that. Generally speaking, how much of a variance is acceptable in weights? The coach rides pretty good but static has a slight right lean. I am aware of adjustment procedures and have had some made but it's not perfect yet. Again driving it feels more level going down the road when considering road surface, crown, etc. Will adjusting the weight loading more left have any significant affect on ride and given the limited ability to load heavier left, will it make much difference?

During normal travel, I have about 1/3rd fresh water but the AK trip will have much more. Flat towing a Jeep so no weight issue there. There obviously have a lot of clothes and food loaded but not much capability to load heavy left. Maybe I'm over reacting or over thinking but I'll reload my basement stuff to concentrate the heavier items more to the left side. Note, the center basement compartments are on the slides so no pass-thru storage. The right side does have deep compartments with 3 tubs that are centered with the slides in.

johnboy2 · 04-07-2016, 06:39 AM

Mine is heaver on the left side do to the slide. I run higher air pressure on the left to compensate.

Gary RVRoamer · 04-07-2016, 06:59 AM

Quote:

Mine is heaver on the left side do to the slide. I run higher air pressure on the left to compensate.

Bad idea! All the tires on the same axle should have the same pressure, both for the health of the tires and best handling and braking. That means they all should have the psi needed for the heaviest side.

If you have air suspension, the ride height control valves should make the coach level when traveling, and the jacks do the same when parked.

chunker · 04-07-2016, 09:07 AM

Leveling when parked is easy of course and it seems to level out when driving. I have been running the pressures the same on the same axel but I'll double check the Michelin book for the recommendation for these tires and weights. I know I'll be heavier when traveling so probably will go with the GARW weight pressure suggestion.

Sweetbriar · 04-07-2016, 09:32 AM

1040 lbs. out of a total of 20000 lbs. is only 5% plus add if the difference between max axle loading and what you have would bring the number down even more. Split the number even further for tire weight and it gets even smaller as a percentage. Moving weight around to compensate can get complicated very quickly. Shifting left to right weight that is too far away from the problem axle could have a greater undesirable effect on the other axle.

I would leave it be as is but to check the ride height valve assemblies. Could be as little as a 1/2" off which gets amplified when you're working with levers, angles, mechanical valve dwell and such.

Crasher · 04-07-2016, 10:36 AM

500# difference in the front and 1000-1200# difference is are acceptable in the RV industry. It's not uncommon and some are more yet. I doubt that you will be able to shift enough load to make much difference and it really doesn't matter. If the front was off more, I would suggest adjusting the ride height to shift the weight off the heavy side, but that would increase one corner on the front. Just keep the rear tire pressures equal on both sides equal the psi needed for the heaviest side and don't worry about it. It's a bad idea to have different pressures side to side.

FIRE UP · 04-07-2016, 12:04 PM

Well,
The "Weight" thing has been on here, oh, about a zillion times and, sometimes people get a bit more complicated than they need to be on this. Weigh the coach, front, back, total. Look up your tire manufacturers website and, find their tire chart. The tag next to the drivers side refers to the max pressure for the max weight. If I'm not running at the max weight, per tire, then I'm not going to run the max pressure. I run what the chart tells me to. It's their tires, not the motor homes.

So far, we've owned the coach for almost five years and have put a modest 22,000 miles on it, running the tires at what Michelin's recommendation has been. The tires are wearing fine, no issues, no wandering, no "rivering" no odd handling problems and the ride is great. Moving stuff around in the compartments would be futile anyway due to the fact that, most of it fits where it's sitting at anyways. Besides, if the wife and I change positions, that alters the weights on the front corners anyway.
Scott

chunker · 04-07-2016, 12:18 PM

I was out having the cooling system flushed and changed and passed by the scales so I wanted to see what the L-R weights were. I suspected to be heavy on the right but was curious what others had encountered. When I load the refer it will be even more but I can move some seldom used heavier items to the left and it will shift some, not much, weight, and make the cargo easier to access based on use. I didn't figure my weights were way off base but wanted to know. At any rate the ride is good.

Ya'll have a good week and season.

**TonyDi** · 04-07-2016, 12:27 PM

Quote:

Originally Posted by Gary RVRoamer

Bad idea! All the tires on the same axle should have the same pressure, both for the health of the tires and best handling and braking. That means they all should have the psi needed for the heaviest side.

If you have air suspension, the ride height control valves should make the coach level when traveling, and the jacks do the same when parked.

Pressure of tires on the same axle should be the same. Whether it's steering, drive, or tag axle.

mel s · 04-07-2016, 12:42 PM

Quote:

Originally Posted by Crasher

500# difference in the front and 1000-1200# difference is are acceptable in the RV industry. .

Crasher

There are a lot of odd ball things are "acceptable in the RV industry" that aren't tolerated or allowed in the "real world".

Crasher · 04-07-2016, 03:41 PM

Quote:

Originally Posted by mel s

Crasher

There are a lot of odd ball things are "acceptable in the RV industry" that aren't tolerated or allowed in the "real world".

Very true, but I don't think this is a big deal. What possible affect could a 5% weight difference between left and right have on a 20,000# rear axle when the suspension is keeping it level? When building these boxes on wheels, certain models can be difficult to layout the appliances and furniture to get to less than a 4-5% difference side to side. My coach was heavy on the front right and also on the left rear. Lowering the ride height one half inch of the LR corrected both problems. The OP could take some weight off the heavy corner, but that would increase the opposite corner. Better to leave it with both fronts being very close.

johnboy2 · 04-07-2016, 04:26 PM

Funny thing The engineers at good year came up with the pressure chart for my tires. true the duels match for one corner but the other rear corner is different rides and handles great.

mvpmich · 04-07-2016, 06:23 PM

Are you going to compute the weight of your added fresh water, gear, food and supplies? That total weight for these items should be used to compute air pressure. Additionally I run with 5 additional pounds of pressure after this weight computation to compensate for misc changing conditions during a trip.

mel s · 04-08-2016, 06:42 AM

Quote:

Originally Posted by mvpmich

Are you going to compute the weight of your added fresh water, gear, food and supplies? That total weight for these items should be used to compute air pressure. Additionally I run with 5 additional pounds of pressure after this weight computation to compensate for misc changing conditions during a trip.

mvpmich

To get weights accurate enough to determine/calculate the tire pressures required a coach should be weighed with tanks filled, gear and supplies on board and the occupants in their seats...(aka: LOADED FOR TRAVEL).

Anything else is an exercise in futility...(aka: a waste of time).

Mel
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