Towing a 3625 with Ford F-350 Diesel

[packwood2]

We are purchasing a new 3625 and will be towing with our 2009 F-350 Diesel crew cab short box. Our truck fully fueled with our auxiliary
tank and two passengers is 9400 lbs in weight. The catalog weight for
the Big Sky 3625 is 12,751 lbs, how much cargo can we add to the RV and
be safe in towing capacity? Should we have any other concerns?

[Art-n-Marge]

First, your truck! You need to look up the CGVWR (combined gross vehicle weight rating) and the GVWR (gross Vehicle weight rating) for your vehicle (pillar and owner's manual will have these). Then weigh your truck with the hitch and all the gear you want to carry plus everything else you already mentioned passengers and full aux tank. Then go back to the scale and reweigh your truck. Subtract the weight you come up with from the CGVWR and this is how much trailer you can carry. Then subtract the weight you came up with from the GVWR and this is how much pin weight you can carry (the part of the trailer that is carried on your truck).

Throw away the catalog for the RV since it does nothing and means nothing but get you in trouble - the catalog is used as a psychological ploy to get you to think you can tow the beast and get the trailer sold! Look at the GVWR of your trailer (aka GTWR), this is what counts and then hope you never overload it. Calculate 18% to 25% of the GTWR and this is the estimate of the pin weight you will put on the truck's rear end. I hope it is less than the number you came up with above at the rear axle, Gross weight and combined weights.

I'm guessing with a short bed, you have a SRW truck. It's gonna be very close. A couple of things that will help - use a simple slider hitch (automatic sliders weigh more) and I hope you have a higher gear ratio for the diff (4.10 or higher). There is no equipment to add that will increase the GVWR of your F-350, no matter what some salesman tells you. Whatever you need to do to the truck, it's way cheaper just to get a new truck. For example, if you have a 3.73 diff, don't bother trying to convert it. It will be cheaper to trade in your truck for what you need, than get all the parts and pay for the labor and then maybe you still fall short.

[DQDick]

Art has pointed you in the right direction. If your truck weighs over 9,000 pounds loaded pay particular attention to how much pin weight you'll be adding.

[1retired06]

Quick estimate, according to the 2009 Ford towing guide: 350 CC diesel,SRW 4X2 tow capacity is 15,800, and 15,300 for a 4X4, with GCWR of 23,000 for both. Using your numbers, you are already at 22151 against the 23,000. That assumes the stated weight for the Big Sky is accurate. Pin weight also has to be factored in.

[Irlpguy]

Packwood2 you are well on your way by knowing the weight of your truck loaded. Just look on the driver side door for the trucks GVWR and subtract your truck weight from that ie: (11,000 - 9100 = 2000). This will give you the additional weight you can carry in the truck via the pin weight of the trailer, to ensure you are not overweight on the truck.

The Big Sky 3625 has a dry "shipping" weight of 12,751 (includes the 2270 listed for pin weight) add to that the carrying capacity of 3019 and the GVWR/(GTWR) is 15,770. That amount or something close should be on the sticker on the front left corner of the trailer.

The pin weight "dry" is listed at 2270 which will increase when you load the trailer or add accessories. If the extra capacity you determined for your truck is anywhere close to the 2270 lbs, then you may have to look for a different truck with a higher GVWR as in a DRW perhaps.

Using the figures provided by Keystone and your 9100 lb truck combined you would have a minimum GCW/CGW (Gross Combined Weight) of 24,870 lbs.

Personally I would first worry about the truck, and secondly the weight on the trailer axles after purchasing and loading, ensuring neither are exceeded.

[Art-n-Marge]

All, I thought an SRW F-350 GVWR was 11,500 if it was a diesel, crew cab, with a long bed and 3.73 diff. With the OPs short bed and if the diff has higher numbers, the GVWR might be higher. That means using IRLP's numbers you gain 500 lbs. Every little bit helps! I do think the CGVWR is either 23,000 or 23,500.

Lots of calculating to do, watch what you load up, then hope ALL the numbers are under your ratings. If any number is over, then you are overweight. Go by the bross weights. Shipping weight can get you in trouble with it's false sense of compliance.

[Irlpguy]

Yes Art the OP's truck could indeed be 11,500 GVWR, my number used was an example only. Using the numbers published by Keystone will not give you the actual final weights but it will give you the minimum you can expect. Weighing the loaded trailer and truck combination is the only accurate way to attain the weights.

Very easy for the OP to determine his truck GVWR and it's GAWR as well, for his particular vehicle and it's options.

[twindman]

Do you really need all that fuel??? I don't know the size of Aux tanks, but it must be large. I have a Silverado 2500 with a slider hitch and I weigh around 8000 with passengers, fuel tank full and 'junk'. So I assume your tank is at least 100 gal if not more. So if it is, just don't fill it so much??? Is that an option. I know it kind of defeats the purpose, but with my 36 gal tank, I can pretty well travel a modest day (320 miles or so) before refilling.
Do what works.

[richfaa]

Our 2008 F-350 CC, Long bed dually weighs in at 9000 + /- 100 lbs or so fully ready to tow.(these Fords are heavy)That aux fuel tank apparently adds a lot of weight to the truck.
a gallon of Diesel weighs @ 7.15 lbs plus the weight of the tank. My guess is you have @ a 60 gal tank on the truck maybe 50 gal. We have been through tgis when we purchased our 2008 Long bed and that is why we purchased the long bed with the larger fuel tank.. Once you get all the numbers you need to determine the pin weight of the Montana and the real carry capacity of the truck... You might be close on that.

[Art-n-Marge]

Twindman, I have a 38 gallon tank and I wished it were bigger a lot of times but I have to be very careful of weight. There are larger tanks whereby you can replace the OEM tank. I would love to do that. I've seen them in 50 or 55 gallon sizes (additional 12 to 17 gallons or another 150 or so towing miles). And the fuel gauge can support a tank this size. When I towed commercially I would have loved to be able to blow by some of those gouging diesel stations, but alas, I couldn't (I paid for my own fuel and gouging fuel stations hurt my bottom line). An aux tank even larger provides even more distance, but then there may be a slight tradeoff in hauling all that weight. It's a choice about refueling distance and convenience, instead of refueling 2 to 3 times a day as a long distance rig hauler (like I did for a little while).

I did use to think just like you, Twindman, because I was a rare-timer and had to stop anyway so why not add some fuel, too. But when I did this as a job, weeks at a time and a lot of stops and had to waste too much time refueling, then that's inconvenient and expensive for some stations and dreams of a larger tank or an aux tank are common.

[packwood2]

It looks like we have some decisions to make without doing much calculating.Today we will do all the calculating but our truck does not seem to be in our favor. Looking at what everyone pulls with made us wonder why so many people have dullys. We went by the dealership yesterday to look at a 450 dully. A new RV is starting to cost some bucks.It's nice to have a place to share so much information. We are
thankful for everyone's input.

[Art-n-Marge]

Funny how that works... We freaked out buying our first Monty, then buying a new the truck (and still falling a little short, so then spent a little more becoming compliant). However, a few successful outings and great memories and doing what we like to do while we're there, and all was not necessarily forgotten, but surely gotten over. No regrets, except, we wish we had a second A/C. What?! Spend more money?! Heck yes! The list is still long.

[richfaa]

Rv'ing is not a cheap past time by any means. Forum like this help one t o make the proper decisions and perhaps save a bit of $$$.