Community Forums

Trap · 02-17-2006, 04:51 PM

Were looking at moving up to Kustom Koach Legacy 328 5'er in the next year or so.

Dry Weight 11440Lbs
Hitch Weight 2053 lbs.
GVWR 13500lbs
Length Bumper to Pin 32'5"
Overall Length 37'5" (Shaped like Titaniums)

Wood a F-350 6.0 PSD SRW with 3.73's work or should we be looking at DRW with either 4.10's or the Tow Boss with 4.30's. Any and all suggestions would be appreciated. Thanks Trap

Trap · 02-17-2006, 04:51 PM

Were looking at moving up to Kustom Koach Legacy 328 5'er in the next year or so.

Dry Weight 11440Lbs
Hitch Weight 2053 lbs.
GVWR 13500lbs
Length Bumper to Pin 32'5"
Overall Length 37'5" (Shaped like Titaniums)

Wood a F-350 6.0 PSD SRW with 3.73's work or should we be looking at DRW with either 4.10's or the Tow Boss with 4.30's. Any and all suggestions would be appreciated. Thanks Trap

RustyJC · 02-18-2006, 04:24 AM

If your objective is to stay within the manufacturer's ratings, you really can't go with brochure information on either the truck or the RV. To explain, the truck's "trailer tow rating" is obtained by subtracting the curb weight of a stripped base truck with only a 150 lb driver from the truck's GCWR (gross combined weight rating). Correspondingly, the "dry weight" of the 5th wheel doesn't include propane, your cargo (food, clothes, "stuff", etc.) and, many times, any options. Many RVers look at these brochure ratings, put a rig together and then find that they're exceeding their truck's GVWR, GCWR, rear GAWR or some combination thereof.

The problem with any SRW truck when towing a 5th wheel is the high percentage (20% to 25% can be typical) of the 5th wheel's weight that is carried by the truck as hitch or pin weight - this weight counts against the truck's GVWR, and the SRW truck has a lower GVWR than the dually, despite the fact that a given SRW truck, being lighter, may have a higher manufacturer's "trailer tow rating".

If you have a realistic idea of the true, actual laden curb weight (LCW) of the truck(s) you're considering or will be using, you can use the following equations to size an RV (5th wheel or TT) that the truck can handle. LCW is the actual curb weight of the truck with driver, passengers, cargo, full fuel tank, options, accessories, trailer hitch, etc. This weight can be obtained by loading up the truck and weighing it on scales that are available at most truck stops - it should cost $10 or less to weigh the truck.

Truck's GCWR - Truck's LCW = maximum allowable total weight of loaded trailer

Truck's GVWR - Truck's LCW = maximum allowable hitch or pin weight of loaded trailer

If you don't know the loaded weight of the 5th wheel you're considering, a conservative approach is to use the 5th wheel's GVWR as the total weight and 20% of the 5th wheel's GVWR as the hitch or pin weight of the loaded trailer in the formulas above.

Good luck with your RV search and welcome to iRV2.com.!!

Rusty

TXiceman · 02-18-2006, 05:18 AM

Exactly what Rusty said again....

Ken

RAM³ · 03-19-2006, 08:35 PM

Too right, Ken!

In the case where the trailer's GVWR is known and the search is on for the truck - as is the case for Trap - the problem gets even fuzzier since the weight of the truck - as loaded - is also an unknown.

Starting with the intended trailer's GVWR [13,500 in this specific case] and a guesstimated pin weight of 2,700 - 3,375 pounds [20% - 25% of GVWR] means that the manufacturer's advertised "cargo capacity" should be in the range of 3,700 - 4,375 pounds to allow for the weight of the hitch, in-bed cargo, passengers, pets, and "stuff".

Personally, I'm not aware of any SRW trucks that have that kind of "cargo capacity".

FWIW, my '03.5 Dodge DRW handles our 14,100 very nicely!

Trap · 03-20-2006, 10:57 AM

Thanks for the replies, We're kinda of leaning towards the F-350 4x4 Dually. I thought it may be a little tight with the SRW. While it would be nicer to have the SRW, I would prefer to be safe when towing. What about gearing should we go for the 4.30 gears or stick with 4.10's

Again Thanks, Trap

**NLOVNIT** · 03-20-2006, 11:19 AM

Trap-
One other thing to consider is, in my opinion, if you have a rear wheel blow out (like we did on our current truck), especially with a 5-r having that high of a GVWR & pin weight, having 3 tires left to hold the weight instead of 1 would be safer, too. It might never happen, but we're testimony that it can.
L-

The Big Kid · 03-20-2006, 04:44 PM

Dually -

I just recently did all the research myself and bought my Ram 3500.

The Max GVWR of the SRW was between 9,900 lbs and 10,500. DRW to around 12,200.

I doubt that your 2050 hitch wieght dry will stay under 2500 loaded. A SRW (ex cab - reg box) with 2 adults, full fuel will scale out to around 8000 lbs (someone with one feel free to correct me - I SWAG'd).

I also really like how the wider stance of the rear wheels makes it feel more solid on the road.

I have 4.10's and I will probably re-gear it down to something in the 3's within the year. I find the truck has the power, but the truck needs to scream to maintain speed limit on freeways.(not speeding - just to not become a hazard myself) The trucks seem to have the power to handle the 3.73 gearing - my last one did(3.53)