3901rk

[drmwentling]

About to pull the trigger on a new 5th Wheel. It will be my first, but I need a bit more room to be full-time in the RV part of the year. My tow vehicle in a 2024 GMS Sierra 2500HD with the 5th wheel prep, so single rear wheel. The specs say I am well within the tow capacity, am I making a mistake by attempting to tow with duals on the rear. Sorry if this is a silly newbie question, but I want to be safe. My travel will be 100% highway, no off-road, and no boondocking.

[jsb5717]

Welcome aboard! You’re asking the right questions but won’t like the answer.

Tow capacity or rear axle rating isn’t really going to tell you whether your truck can handle that trailer. The sticker inside the driver door that tells you “Cargo and occupants not to exceed xxxx lbs” (or something like that) will give you the total payload for that truck. That’s the only number you need. Your calculated loaded pin weight on that trailer will be in the neighborhood of 3500lbs. Add hitch weight, people, and other gear to that weight. The total number needs to be under your truck’s rated payload. Your 2500 will be underrated for that trailer. You will need a minimum of a 3500 and more likely a dually to be safe.

The 3901RK is a lot of trailer. It’s a very nice floor plan. Good luck in your process.

[drmwentling]

This is where I get confused…the GMC is rated for 19,300 lbs 5th wheel tow (the 2024 2500HD with 5th wheel prep is on the 3500 chassis), with 3829 lbs on the pin. The trailer specs are 16,800 lbs (max weight loaded), with 2975 lbs on the pin. So on paper it should work, but I am trying to cross my T’s before I sign the papers and drive away on Friday.

[RMcNeal]

Like Jeff said, ignore what the "total weight" you can tow rating is. That's always going to be higher than is really possible given the truck's payload capacity. Look on the door pillar for the cargo capacity on your specific truck. Typically, most F250/2500 trucks have a total weight rating around 10,000 lbs. Whatever the truck weighs empty, plus fuel, cargo and occupants must be less that that total capacity. Doesn't leave much room for pin weight which has to be included in the truck's cargo capacity.

[drmwentling]

So the sticker in the door pillar says:
GVWR: 11750
GCWR: 30000
RGAWR: 7250
CURB WEIGHT: 8429
MAX PAYLOAD: 3321

TWR
CONVENTIONAL: 20000
MAX TONGUE WEIGHT: 2000
GOOSENECK TWR: 21600
MAX TONGUE WEIGHT: 3240

The trailer loaded (max) according to its sticker is 16800, with a pin weight of 2975. On paper it seems a legal and safe tow, however if I understand what is being said here this is not correct, and I should cancel my purchase as I do not have enough truck to tow safely. It will be one person in the truck and an 88 lbs Service Dog. The trailer will have clothes and reason household items for trips of 2-4 months (food, dishes, etc.).

[RMcNeal]

Just my opinion, so take with a grain of salt...
Your max payload is 3321 from above. The trailer pin weight is 2975 (seems low but). That leaves you 346 lbs for fuel, passengers and anything else you wish to carry. Not much leeway. Remember your payload is a combination of passengers, fuel, tools, firewood and anything else you want to carry in your truck.
That's kinda what I meant before. Your max twr for goose neck is 21600, but there's really no way to get there without going well above your payload max.
Very confusing and deceiving.

[drmwentling]

Thanks, I am going to cancel my buy. The math says I cannot do this safely.

[RMcNeal]

Just to ensure yourself, you might see if the dealer will allow you to take the rig to a cat scale and weigh each axle. That way you have hard numbers to verify your math with.

[jsb5717]

Also, the published pin weight of the trailer isn't the real, loaded pin weight. You either have to load your trailer and take it to the scales or you have to calculate the loaded pin weight. 23% of trailer GVWR is the place to start

[sberlin]

We have a 2018 3701lk and started with a 2015 Chevy 2500hd and we’re about 300lbs over. Traded in truck for a 2015 GMC 3500hd and were within limits. The newer trucks like yours have higher weight ratings. My feeling is the key number is the rear axle weight with your trailer and you should be right there. The payload might be a little over. My 2023 GMC 3500hd has a rear axle of 7250 but a payload of 3750. In total you are right there and I think will work.

[sberlin]

Originally Posted by drmwentling

About to pull the trigger on a new 5th Wheel. It will be my first, but I need a bit more room to be full-time in the RV part of the year. My tow vehicle in a 2024 GMS Sierra 2500HD with the 5th wheel prep, so single rear wheel. The specs say I am well within the tow capacity, am I making a mistake by attempting to tow with duals on the rear. Sorry if this is a silly newbie question, but I want to be safe. My travel will be 100% highway, no off-road, and no boondocking.

PS- our rig is rated at 16,400 and we’re always 14,600 when traveling

[jkxtreme]

We live in a 2023 model 3901RK and love it. Plenty of room and lots of storage. However, we pull it with a Ford F350, 1 ton dually. We opted for the F350 so we had a bit of safety factor. This truck has no issues pulling this trailer whether it's up a big mountain or on the flat. The 3901RK is a lot of trailer and is heavy (16,500 lbs) The rear kitchen can be an issue because of the whip up and down and the weight at the rear of the trailer, so we have designed apparatus to hold everything in place as we travel (pics available). We will install shocks on the trailer once we get back to central Florida to try to control the up and down movement.
My wife loves to cook and she brought all of her cooking 'toys' with her so we needed the storage space. I keep 90% of my tools in a tool box at the back of the truck and most of our heavy stuff is in the front compartment. We also installed a generator (not onan) in the front. Copy/paste this link into your browser to see our youtube video of the generator installation. https://youtu.be/RVB_UazYH7I?si=vCGHjznWr5ZgzavL

[JABURKHOLDER]

Just another opinion:

I see you cancelled your truck order. Good start.

While looking for a new truck please consider the following; recommended 5th wheel pin weight is 15%-25% of the rv weight. Unless you have already weighed your rv, fully stocked for travel, you don’t have an exact weight to figure your pin weight. The one weight you do have is the GVWR of your rv which is 16800lbs. Take that weight and multiply by 25% (the max pin weight) and use that as your starting point. That number is 4200lbs. If any truck you are looking at doesn’t have that as a minimum payload capacity, walk away.

Just my two cents.

[drmwentling]

Originally Posted by JABURKHOLDER

Just another opinion:

I see you cancelled your truck order. Good start.

While looking for a new truck please consider the following; recommended 5th wheel pin weight is 15%-25% of the rv weight. Unless you have already weighed your rv, fully stocked for travel, you don’t have an exact weight to figure your pin weight. The one weight you do have is the GVWR of your rv which is 16800lbs. Take that weight and multiply by 25% (the max pin weight) and use that as your starting point. That number is 4200lbs. If any truck you are looking at doesn’t have that as a minimum payload capacity, walk away.

Just my two cents.

Nope, I kept the 8 week old truck and went to a smaller MONTANA 3123RL. I am within gross and truck axle payload limits now with room to spare. I gained a ton of space over my conventional trailer, and will no longer be concerned about the legality of the tow combo. As a bonus I am now in a full time rated trailer.

[JABURKHOLDER]

Misunderstood what purchase you were canceling.

I believe you still have a problem with your rv choice and tow vehicle. You are still using the wrong numbers in your calculations. Your gross weight is irrelevant. It’s the pin weight of the rv and the payload capacity of your truck that are the main concerns and yours don’t add up.

Rv numbers: shipping weight 12482lbs
CCC 3868lbs
GVWR 16350lbs

As I posted before, use 25% of your GVWR to calculate max pin weight and use that number as a starting point for available payload in a truck. That number would be 4087.5lbs. Way over your GMC’s payload rating of 3321lbs. To make matters worse that will not be your trucks real world capacity. Subtract fuel weight, 36 gallons x 6.3 per gallon gas, 226.8lbs. Subtract hitch weight, approx 100lbs. Subtract your weight, just a guess, 170lbs. Subtract your dog, 88lbs. Your trucks remaining payload capacity is now down to 2895.2lbs.

I’m pretty sure you will almost never have your rv loaded out at 16350lbs but it is reasonable to believe you will add 1000lbs, which includes 60lbs of propane, to the rvs shipping weight. You would be at 13482lbs for the rv.

Most rv’ers come in at 22% pin weight. That comes to 2966.04lbs. That puts you over your trucks payload capacity. 70.84lbs over and no safety cushion.

Based on available info, you should look for an rv with a max GVWR of 13160lbs or less.

I’m not saying what to do, just pointing out the math with the numbers you supplied and the advertised specs of a 3123rl.