Tank location - 310 specific

[JColeman]

All the TV issues aside, it should be possible to effect the pin weight by adding or subtracting water weight if any of the tanks are behind the axles. When I look under my rig, the fresh water dump is well behind the axles but that doesn't mean the tank is there.

Can any of you who have either pulled the chloroplast or been to the factory tell me the actual location of the fresh water tank? Grey/black?

[dmasters]

I have the 372 which has the dump value behind the axles, and have the same questions, so, i just did a simple test. I filled the fresh water tank with 90 gals of water, about 600 lbs, and watched my pin weight change by a couple hundred pounds.

[boyscout]

All the TV issues aside, it should be possible to effect the pin weight by adding or subtracting water weight if any of the tanks are behind the axles. When I look under my rig, the fresh water dump is well behind the axles but that doesn't mean the tank is there. Can any of you who have either pulled the chloroplast or been to the factory tell me the actual location of the fresh water tank? Grey/black?

I just found an assertion by @Second Chance - NOT model-specific - that the fresh tank rests over the axles and therefore doesn't change pin weight much.

I'm just the reporter, don't know if this is true for the 310GK.

You likely already know that the fresh overflow is just behind the axles, and I'd *guess* that the overflow would be routed out the top and down one edge of the tank. If the assertion above is correct, our valves may be near the rear edge of the tank.

[bertschb]

I can't speak to the 310GK but the fresh water tank is behind the axles on the Solitude 373FB.

[Airrace]

Having had the cover off my 310 GK I can tell you that the fresh water is about 24 inches aft of the rear (2nd) axle. While weight aft of the axle (or CG) will lift the pin 24 inches is not a long enough lever (arm) to do much. The waste tanks are forward of the axle. Couple days ago while returning from a dry camping trip I weighed the unit with no fresh water and about 70 gallons in waste tanks and 48 gallons of fuel, then with 30 (about) gallons fresh water, empty waste tanks and 36 gallon fuel and was surprised and the result. The trailer axle was the same. The real axle (truck) was reduced by almost 400 pounds.

[andrewssteve]

The real axle (truck) was reduced by almost 400 pounds.

"not a long enough lever (arm) to do much." I don't understand. 30 gallons => 400 # off pin. That's huge! Why do you say filling the freshwater tank won't do much?

[Airrace]

No the 30 gallons did not take 400 pounds off the rear axle. The 70 gallons (595 lbs.) and 12 gallons of fuel (80 lbs.) is what reduced the axle load. 24 inches and 30 gallons of water (255 lbs.) is maybe enough to lift the pin by a pound or two. My qualification for weight and balance is 23 years as a loadmaster in the Air Force.

[boyscout]

"not a long enough lever (arm) to do much." I don't understand. 30 gallons => 400 # off pin. That's huge! Why do you say filling the freshwater tank won't do much?

In addition to adding 30 gal of fresh water @Airrace dumped 70 gal of waste water. The waste water alone would weigh 500+ pounds.

[Vroman]

Airrace,
I have a tech question for you, and thanks for your response. What are your thoughts on reducing pin weight by using a trailer hitch cargo box on rear of my Solitude and moving cargo from garage and front storage bay to the cargo box. Trying to get about 350lbs off the pin.

[Airrace]

While that could be done I would be very careful of putting that much weight at the rear of the trailer. Most of the hitches used are only rated for 100 lbs. tongue weight and I have no Idea what Lippert is saying about hitches at the rear bumper. I went the other way and traded a really nice SRW for a DRW.
But the answer to your question is to lift 350 pounds off the pin would take 565 pounds sitting on the metal sewer tube. 252" from center of axles to pin X 350 pounds = 88,200 moments divided by 156 " from center of axles to rear bumper = 565 pounds.