Towing Question? - Diesel Forum

Pol386 · 10-15-2009, 08:09 PM

Any help is appreciated, we are looking at a 2010 Cardinal 5th wheel model 3515RT. It weighs 12855 with a pin weight of 2135. We have a 2008 F-350 SRW 6.4 as a tow vehicle. My question is, can I safely tow this amount of trailer with the vehicle I have. Thanks RWH

knoweigh · 10-15-2009, 09:02 PM

Quote:

Originally Posted by Pol386

Any help is appreciated, we are looking at a 2010 Cardinal 5th wheel model 3515RT. It weighs 12855 with a pin weight of 2135. We have a 2008 F-350 SRW 6.4 as a tow vehicle. My question is, can I safely tow this amount of trailer with the vehicle I have. Thanks RWH

that's a walk in the park for that truck. IMHO

I'd pull that load all day long even through mountains if I had to, w/ my y2k F250

I'm sure more will chime in.

SmokeyWren · 10-15-2009, 09:03 PM

Cardinal 3515RT is a 40-footer with 4 slides and a GVWR of 16,135 pounds. Wet and loaded hitch weight will be about 2,886 if you balance the load in the trailer to result in 18 percent pin weight.
Cardinal 3515RT

2008 F-350 SRW 4x4 CrewCab has a GVWR of 11,500 pounds, and a GCWR of 23,500 pounds.

11,500 GVWR minus 2,886 pin weight = 8,614 max weight of the wet and loaded tow vehicle before you tie onto the trailer. That's a reasonable expectation for your truck if you don't have a toolbox full of tools and three NFL linebackers in the back seat.

If you try hard, you can probably get the weight of your wet and loaded tow vehicle down to 8,614 pounds before you tie onto the trailer. So you won't be over the GVWR of the tow vehicle, which is the usual problem with trying to tow a heavy 5er with an SRW pickup.

So that leaves a max trailer weight of 14,386 without exceeding the GCWR of your tow vehicle. Your truck can handle the hitch weight with no wiggle room, but when the trailer is wet and loaded for a long trip with a 16,000 pound gross trailer weight, you're going to be straining the guts out of your tow vehicle. Stay away from mountains, or even hill country, and travel with the holding and fresh water tanks empty, and you can probably "get by" safely.

But if I'm hauling wife and kids and grandkids and great-grandkids, I would want a tow vehicle with at least 26,000 GCWR to tow that monster-size trailer. 2005-up F-350 DRW with the TowBoss pkg, or F-450 pickup. Both of those have at least a 4.30 rear axle ratio.

So one patch to help you tow that big trailer with your not-quite-enough truck is to change the ring gear and pinion in both differentials to a 4.30 ratio. That won't beef up the frame and suspension and brakes to match the duallies, but at least you won't be a rolling roadblock when climbing a big hill or a mountain pass, so it increases your safety.

(Yes, I have great-grandkids.)

rskeans · 10-15-2009, 09:06 PM

Quote:

Originally Posted by Pol386

Any help is appreciated, we are looking at a 2010 Cardinal 5th wheel model 3515RT. It weighs 12855 with a pin weight of 2135. We have a 2008 F-350 SRW 6.4 as a tow vehicle. My question is, can I safely tow this amount of trailer with the vehicle I have. Thanks RWH

The 3515RT GVWR weight is 16,135 lbs. The weight you provided is the dry weight. You need to use the GVWR weight. I haven't researched all of the towing and weight specs, but I believe that you are significantly over the maximum weights for your truck. You didn't provide the axle ratio, or other things that affect your maximum towing capability.

All the above being said, it is not uncommon for such weight to be pulled behind your 350. Your brake controller will control the trailer braking. IMHO that is the most critical thing. You could be subject to some liability if you should be in an accident.

RajinCajun · 10-16-2009, 11:09 AM

TON OHV, Jeeps, and 4WD Galleries :: Truck and 5er Pics :: DSCN1379
2003 F450, 4x4, 4 door, Western Hauler flat bed
2005 Tahoe Transport 36' 5er, Onan 5.5 genny

Full tank of fuel, 3/4 tank fuel on toy hauler, all cloths, spare tires, tools and all of the stuff required

Fast Track Scales in Madison, FL 18 Jul 09

Steer 5040
Drive 7740
Trailer 12440
TOTAL 25220

Took this set up from TX to FL in July, towed like a champ, and there were several times when passing or being passed by 18 wheelers in traffic, in Mobile for example... I liked the added safety of the F450. With my wife and kids loaded, it makes me feel safer and less of a white knuckle drive.

I vote upgrade tow rig for RV of that size.

bogg · 10-16-2009, 04:22 PM

I went thru that in 2005 when I bought a new 30 foot 5th wheel to pull with my 03 F250. After a few years of 'worry' but getting the job done anyway, we upgraded to a DRW F350. I would keep your sites around the 30 foot range/12000# GVW RV pulling with the F350 SRW

Pol386 · 10-16-2009, 06:20 PM

Sorry for the lack of info our f-350 has 3.73 rear gears, I guess my next question is what weight 5th wheel should we be looking at that we can safely pull with enough wiggle room. Thanks RWH

SmokeyWren · 10-16-2009, 08:25 PM

In my first post in this thread I noted: "So that leaves a max trailer weight of 14,386 without exceeding the GCWR of your tow vehicle."

So figure on a trailer GVWR of around 14,000 pounds. That's a hitch weight of about 2,500 pounds.

If your wet and loaded trailer grossed 14,000 pounds, that would leave 9,000 pounds for the max weight of your wet and loaded tow vehicle before you bumped into the GCWR of the tow vehicle. That should be do-able.

If your hitch weight were 2,500 pounds, that would also leave 9,000 pounds for wet and loaded tow vehicle weight before you exceeded the GVWR of the tow vehicle. So it sounds like you should find a trailer with a GVWR of not more than about 14,000 pounds.

All the Forest River Cardinals are too heavy, but if you like the Forest River brands, then check out the Clear Creek 34SATS. GVWR less than of 14,000, which is right up there just below your max trailer weight. And the floorplan is similar to the bigger, heavier Cardinal you like, except three slides instead of 4.

Cedar Creek 34SATS

There are two other Cedar Creek models that begin with "34" that have GVWR of about 14,000 pounds, so check out those too.

You probably wouldn't be overloaded with the 34SATS or one of the other 34s (that are actually almost 37' long), but that trailer wouldn't leave you much wiggle room. If you prefer wiggle room, then scale down to a trailer with a GVWR around 12,000 to 13,000 pounds. Then your main concern would be not overloading the trailer with too much "stuff".

Pol386 · 10-16-2009, 09:05 PM

Smokey, Thanks for all your info I just don't want to overtax the truck. Your info was very helpful. We are leaning toward a Forest River product unless you can suggest better option. Thanks again, Randy

SilveradoHauler · 10-16-2009, 09:47 PM

I would not run that combo out here in the Pacific NW where we have real mountains.

Like the Cajun, I pull with a F450. Trailer is around 16,000 ready to go. Not a bad towing rig except for the 4R100 Transmission.

However, next truck will be at least 26,000 GVW.

If you want more reality answers, google and jump over the the Escapees Discussion Forum and post. Those guys like Class 8 Heavy duty Trucks modded to a single rear axle.

SmokeyWren · 10-17-2009, 01:38 PM

Quote:

Originally Posted by Pol386

We are leaning toward a Forest River product unless you can suggest better option.

"Better option", I don't know. But if I were a rich man I'd look at the Holiday Rambler Alumascapes.
Holiday Rambler

The key to any trailer you look at is two 6,000 pound trailer axles. Or two 5,000 pound trailer axles if you want more wiggle room before you bounce up against the "overloaded" ceiling.

When you weigh the rig while on the road, it's a PITA to determine gross trailer weight. The CAT scale will tell you front axle, drive axle, and trailer axles weights. If you have two 6,000 pound axles with tires rated at least 3,000 pounds each, then keep the weight on the trailer axles below 12,000 pounds, and you'll know your trailer is not overloaded. Keep the weight on the two truck axles below the GVWR of the tow vehicle and you'll know you're not over that limit. Keep the combined weight of truck and trailer below the GCWR of the tow vehicle, and you'll know not to fear any mountain pass.

And the trailer tires on 6,000-pound axles are the ordinary LT235/85R16E all-position truck tires that were OEM on our pickups before the '05 model year. Lately there are also ST235/80R16 (special trailer) tires available. Add 18 percent to the trailer combined GAWR and you get really close to the GVWR of the trailer, i.e., about 14,000 pounds. But the trailer GVWR is meaningless except for estimating purposes. Your actual trailer weight limiter is the trailer's GAWR. And the CAT scale ticket tells you the trailer's GAW.

SilveradoHauler · 10-17-2009, 07:26 PM

One key thing most folks do not think about with heavy trailers is the trailer brakes.

Only thing making the brakes work is the trailer plug connection and a wire going back to the electric brakes.

If you have a broken wire, bad connection in the plug, or the plug is loose or falls out of the receptical on the truck, then you have no brakes.

Put that heavy trailer behind a undersized pickup, start down one of the 6 percent grades of 10 miles or more (real common out here in the Cascades and Coast Range and the Rockies), and you will have a runaway if you have no trailer brakes. The bigger the tow vehicle, the better chance you have of slowing the combination down with no trailer brakes.

If I were towing that trailer the tow vehicle would have a torque converter lockup control (if the trans was an auto) and a exhaust brake.

Bill1013 · 10-18-2009, 10:05 PM

Quote:

One key thing most folks do not think about with heavy trailers is the trailer brakes.

Only thing making the brakes work is the trailer plug connection and a wire going back to the electric brakes.

If you have a broken wire, bad connection in the plug, or the plug is loose or falls out of the receptical on the truck, then you have no brakes.

On most ALL RV's they do a lousy job on the brake wiring at the wheels. Get some split plastic conduit to protect the wiring, wire tie it up behind the axles as much as possible. Road debre can possible break the wiring especially on gravel roads. Ask me how I know.

Pol386 · 10-24-2009, 01:48 PM

Thank you everyone for your input, we have it narrowed to 3 possibles. Each unit is around 14000 to 145000 so this should be fine. The salesman will sell you anything you want you have to do your research and i thank you for your help. Randy

I will post pics of new 5th wheel when we get it.

shooter 7 · 11-12-2009, 11:58 PM

Excellent advice. Engineering specs exist for a reason. Because you "can" do something does not make sense when routinely exceeding mfgr specs. All parts have to work in synergy, or weak link failures result. How safe do you want to be? Stay within spec load limits & you won't compromise designed safety tolerance. Mass in motion is a powerfull thing. (think .22 vs .45 cal) I'd not want a run-away in mountains, nor be left with a blown drive train while rv'ing because I "could" do this or that beyond spec. Even top fuel dragster pros suffer come-aparts, & they have $ & savvy to push the margin to it's ragged edge.