Half ton TV advice

bmcewan wrote:
My problem is, between the wife and I and a full tank of 26g of fuel, plus 50# of extra gear, and subtracting the 150# of driver weight (boy I wish I was back at 150#!) we're left with payload of 870 pounds.

Dialing in the tongue weight at 15% of trailer weight, I'm looking at a limit of 5800 pounds.

Have I calculated this correctly?

The first step is to verify your payload estimate of 870#.
This can be done by loading the TV as it would be loaded for camping and subtracting its loaded weigh from the GVWR.

Assuming the available payload is 870#, we can make the following estimates:

The weight of a WDH also must be treated as TV cargo.
Assuming a WDH weight of 100#, reduces the available payload to 870-100 = 770#.

Using a properly-adjusted WDH will cause a load equal to approximately 20% of the tongue weight to be transferred to the TT's axles.
This means a load equal to approximately 80% of TW will be carried by the TV.
The maximum allowable TW then will be 770/0.80 = about 960# (assuming the TV's receiver is rated to carry that much).

It is reasonable to assume the loaded TW% can be held to 13%.
This means the maximum allowable loaded trailer weight could be 960/0.13 = about 7400#.

Of course, this all depends on the actual available payload and the receiver's TW rating.

If you carry only 50# of extra gear, I see no need for an airlift system.
If you do use an airlift system, you need to ensure it does not interfere with the WDH load transfer.

Ron