Thank you for all replys. I hadn't heard, or at least hadn't thought about the 20% figure for the hitch weight. Looks like I will probably need a one ton truck for an approximate 2500lb to 2800lb pin weight. Depending on which trailer we decide on. Does that sound about right?
The one thing to be careful of when compairing a 3/4 ton to a 1 ton, is the published weight of each truck. The GCWR or a 2000 Dodge 2500 was 18,000 as was the 3500. The GVWR of the 3500 was 400# greater. Yet the weight of the truck ate up the differance as the 3500 was much heavier. Thus my 2500 could handle a heavier 5er than a 3500.
USN RET. 2001 Diesel Dodge Quad Cab 2500 Auto w/4:10 rear end. Miller Mfg Truck Bed Cover, with RBW hitch, and a 1995 29' Automate 5th wheel with one slide
Judgerr
I am a newbie too, trying to pick the trailer before the truck to make sure we get the right rig for the job. We are looking at a 5er that has a d/w of 12,450 and loaded gvwr of 14,500. Everyone says (ford. gm and dodge dealer and RV dealer) says the 350,3500 will do. Well, I am finding out that yes it will pull it, but what hap[pens when you are coming down that mountain?One of the main differences I am looking at is the brake surface area diffreence between the 350 and the 450. MAJOR difference, as well as axel weight and a few other specs.
Someone said either in this forum or one of the others "will the 350 pull my rig, sure it will, will it stop". I am sure this will open up a can of worms, but being a newbie, I would welcome some dialouge on this subject.
that's my $.50 worth.
Gary
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Run a search for fifth wheel weights and you'll find lots of discussion on this subject. fifth wheel mfgrs. use 15%-18% of the UVW for pin weight, but typical loading upps this to around 20%, and up to 25% for some folks-which is quite heavy-and time to leave the kitchen sink at home. The stopping issue is null and void as far as I'm concerned. Once again, the 5er mfgr. designed the brakes to stop the RV at it's GVW, just as the truck mfgr. designed the brakes to stop the truck at it's GVW. If one has trouble stopping both units they need to troubleshoot their braking system to correct the problem. A lot of the electronic brake controllers are junk, remember- you really do get what you pay for! That's my opinion; it and a dollar will get you a coffee at a local diner.
Judgerr
Here is the process I went through when I ordered a my new Titanium which has the following listed:
GVWR - 10170, pin weight - 1604, dry weight - 8037. Dodge GVWR - 8800, GCVWR - 18,000.
Truck Weights
You don't need to weigh the trailer. All our computations are based on the known weight of your truck after you weigh it. With two people, dog, full fuel tank, 220 lb. generator, hitch, firewood, leveling blocks, satelite dish, and two five gallon fuel tanks [generator gas and diesel] mine weighed:
front axle------------4140
rear axle-------------3080
gross weight----------7220
My GVWR---------------8800
less gross------------7220
available load--------1680 lbs. [read kingpin weight]
28E33 kingpin wt.-----1604 lbs. [Looks okay right? keep reading]
My truck GCVWR---------------18,000
Less truck GVWR---------------8,800
Maximum weight of trailer-----9,200
Max. GVWR 28E33--------------10,140 [includes 485 lbs. of fresh water]*
less 2/3 of water---------------323
effective GVWR of trailer------9,817
less dry weight of trailer-----8,037
Cargo carrying capacity--------1,780 [of trailer]
Now let's compute the kingpin wt. of the trailer using the effective GVWR. Kingpins weigh between 20 and 25% of trailer GVWR.
9817 X 20% = 1963 lbs.
less my available load------1680
overload-------------------- 283 lbs.
X 25% = 2454 lbs.
less my available load------1680 lbs.
overload---------------------774 lbs. [looks bad huh? Remember, I have a thousand pounds of generater and other junk in the bed. I could leave some or all of it home. Or I can upgrade the carrying capacity of the truck.]
Let's look at the rear axle which is supporting all that kingpin weight. When I weighed the whole rig, the front axle picked up 100 lbs of the kingpin weight, but most of it went on the rear axle. These are the ratings of my rear axle taken out of the brochure that came with the truck.
Axle max. rating-------------7500 lbs.
Springs max. rating----------6500 lbs.[upgraded to 7400 lbs. Added leaf to springs]
Tires max. rating @ 80 psi.--6160 lbs.[upgraded to 6960 lbs. 265/16 "E" rated tires]
Now according to truck GVWR, if I subtract the actual wt. of the front axle [4140 lbs.]it means the max. load capacity of the rear axle is only 4660 lbs. Whereas the weakest of the three items above is the tires [6160 lbs.]
This disparity indicates that more is involved in the truck GVWR than just weight on the bed of the truck. I think they are considering such things as:
1. Brake capacity
2. Stability in turns and on wet roads
3. Strength of the truck frame
4. Strength during unusual stress like running over a bad stretch of road or railroad grade crossing.
5. Stress on the transmission which is a real worry on my truck. Hill climbing and decending with autotrannys creates a lot of fluid heat that can kill it if it gets too hot for too long a period and you don't change your fluid and adjust your bands every 12,000 miles.
I did a proportion computation using the upgrade numbers above and came up with a new truck max GVWR [estimate] of 9680 lbs. This gives me an estimated safety margin of 240 lbs. on my max. GVWR. [see actual numbers below]
front axle-----------4240 lbs.
rear axle------------5300
trailer axle---------7700
Gross Weight--------17240 lbs. [18,000 GCVWR. Marging 760 lbs.]
rear axle [actual]---------5300
less axle without tow------3080
Kingpin weight-------------2220 lbs. [about the middle of range computed above]
Actual Truck WT.-----------7220
Kingpin wt.----------------2220
Actual truck wt. towing----9440 lbs.
New estimated GVWR 9680
Difference----------------- 240 lbs.
Actual trailer axles-------7700 lbs.
Kingpin weight-------------2220 lbs.
Total trailer weight-------9920 lbs.
Trailer max. GVWR---------10170 lbs.
Difference---------------- 250 lbs.
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cwsoules: "...be careful of when compairing a 3/4 ton to a 1 ton...." What I've read is the Ford F250 and F350 are nearly identical, yet the F350 has a higher GVWR. A significant difference is you can get a dually only in the 350(0)s.
Like Ray,IN says, RV brakes should be designed to stop the RV, so, theoretically, the truck just needs to handle the extra pin weight. You do need a good brake controller. If you have a diesel, an exhaust brake will help and save wear and tear on the truck's brakes. Otherwise, you need to know how to use gears going down a mountain.
Dealer's brochure says the pin weight on our fiver is 1940 lbs. Delivered, I'm sure it was more because UVW (unloaded vehicle weight) was more than the brochure. Loaded for a weekend, with full water tank, on the scale, pin weight is 2320 lbs. Brochure says UVW is 9130 but the sticker on the cabinet door in the FW says 97xx (options and fibreglass exterior add to the brochure indicated weight). On the scales, the fiver weighs 11,100 with full fresh water tank, full propane, battery, loaded for a weekend and about 1/2 full on the gray and black tanks.
Steve Reigle
Fulltiming in a 2003 Montana 3295RK
2003 Ford F350 SD SC SB SRW 6.0PSD AT 4x4 Montana Owners Club
Texatdurango, Sirdrake...where are you guys. OK I'll try it.
Obtain the GVWR and the GCWR for your truck either from your door sticker, dealer, or perhaps Trailer Life Towing specs from their web site.
Load everything in your truck as if you're going camping including hitch, wife/family, full of fuel and everything else you might take. Weigh it. The result is weight "A".
The trucks GVWR minus weight "A" is the available weight you can add for pin weight from a trailer. Pick a trailer, take 20% of the trailer's GVWR and add it to weight "A". If it is more than the trucks GVWR you may end up overweight.
Add the trailer's GVWR to weight "A". If it is more than the truck's GCWR you may end up overweight.
This is very simplified. There are maximum weights for the truck axles both front and back also but this will get you close without actually having a trailer to weigh.
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