5th Wheel Novice Needs Advice!

laknox wrote:

WeGoCamping wrote:

laknox wrote:

WeGoCamping wrote:
Thanks for the replies! My GVWR is 8600 lbs (4250 Front and 6000 Rear). Trailer GVWR is 10,200 lbs. Trailer Gross Dry Weight is 7200 lbs. Hitch weight is 1420 lbs according to the trailer specs...so I assume this applies to the portion of the hitch on the trailer?

Without actual weights, you're right at 2,000 lbs on the pin with that FW. (1420/7200)*10,200 = 2,011. Add the weight of a hitch, people, fuel and "stuff", and you're at ~2,500 cargo for your truck, ASSuming the ratio of 19% stays the same. If it loads more to the front, it could be even more. Probably =way= over the payload rating for that truck.

Lyle

So if I understand properly, you're evaluating the max load on each axle in this case? So If I have 6000 lbs capacity on the rear axle, and lets assume I have 2200 lbs dry on that axle (I'll weigh the truck axles soon), then that gives me 3800 lbs capacity. You're saying I should expect around 2000 lbs pin weight from the 5th, so that would leave me 1800 lbs for people and gear. Assuming that's under the total 8600 GVWR, I would be okay, correct? (At least in terms of weight ratings?)

I don't see a separate payload rating for this truck besides the fnt/rear axle ratings and GVWR. This is a full 3/4 ton with semi-floating rear axle 3.73 gears. I could see how that can come down to distribution from the front to rear. It seems it would take some careful measurement and adjustment.

Not at all. We're talking the weight on the king pin, that the truck will carry in the bed...along with the hitch, fuel, people and "stuff". That is =all= your payload for the truck. Unless you have a way to actually weigh the truck and trailer, you can only guess what the max weight on the pin will be by finding the ratio of the dry pin wt divided by the total dry wt, then multiply that by the GVW of the FW. This does =not= take into effect how you have the FW loaded. If your fresh water tank isn't right over the axles, your ratio could be =less= or it could be =more= than the 19% calculated by the weights you posted. Also, if you pack the front storage, or have a generator compartment, you could be upwards of 22-25% pin wt ratio and be even heavier on your truck. This whole thing is, IMO, something that the manufacturers avoid at all costs, because they know that the vast majority of FWs are going to be loaded above the average truck's capacity. If they truly cared, the manufacturers would randomly weigh their products at campgrounds around the country and make detailed notes on loading and SHARE that info publicly. I know I'm most likely slightly overweight and I will shift stuff to the back of my FW to lighten the load when I can (canned goods, water jugs, etc.), and I carry as little fresh water as I can when I'm going boondocking, then stop at the closest spot to our usual site to tank up.

Lyle

Okay, so calculating the ability to tow a 5th wheel is pretty much the same as assuming a load in the bed, except that the load is centralized on the rear axle to a great degree and will have little affect on the front axle.

I'm lucky enough to have a public truck scale on the side of the road very close to my house. I'll run the truck over the scales to see what the weight on each axle is with full fuel and without gear/people. I can estimate the gear/people and do two evaluations:

1. See if the truck + people + gear + estimated pin weight is less than the 8600 lbs GVWR. If so then I'm well within the truck rating with margin.
2. If not in the GVWR above then compare against the 6000 lb RAWR as a minimum safety measure.