How much weight can I haul safely

[scottiv]

I would like to purchase Sierra 345RET empty weight approx 11,000 lbs I have a 2500 Dodge diesel that is rated for 12,800 lbs. I am sure with more options , water , food and personal items it would increase the weight approx. 1,500 lbs. My question is, will my truck be able to handle that much weight safely. Thanks scottiv

[RustyJC]

I noticed that this is your first post, so welcome to iRV2.com. We're glad you found us.

To answer your question, I'd suggest reading THIS WRITEUP by iRV2.com member Ken Lenger. It covers just about everything you need to know regarding towing calculations. At the bottom of the writeup is a link to an Excel spreadsheet that you can use to make your own calculations given the weights and ratings of your particular truck and the RV you're interested in.

Rusty

[TXiceman]

Check out the article suggested by Rusty. A 34'' 5er loaded will be closer to 12500# and a pin weight of about 2500# which is probably going to put you over the GVWR for your 3/4 ton truck.

Many people find out that the short coming of the 3/4 ton truck is the ability to carry the pin weight where a 1 ton dually will do it without problems. To stay within your truck ratings, you will need to weigh the rig loaded for travel and work through Mr. Lenger's spreadsheet.

Ken

[450Donn]

Please, please remember that "dry' or "shipping" weights are totally useless. Lacking actual scaled ready to camp weights please only consider a trailers GVWR for all calculations.
Now, is this a TT or a fiver? If it is a fiver again you need to take your truck loaded ready to camp to the scales and get accurate weight numbers. Anything else is only a guess.
But I will tell you that if this is a fiver what will kill you will likely be the pin weight which can approach 20% of the trailers GVWR. And that weight is directly over the rear axles of the truck.

[Vulcangw]

Scottiv,

I have a short bed crew cab Chevy Silverado 2500HD with Duramax/Allison. I have pulled two fivers with it, a Forest River Wildcat weighing about 10,500 loaded, and now a Newmar Cypress weighing over 14,000 loaded. When I recently weighed the truck with Cypress, I was under my GCWR by several hundred pounds, slightly over my rear GAWR (by under 150 pounds) and WAY over my truck's GVWR (GVWR = 9,200, actual weight = 10,500).

If you read my posts under the thread "How to stop rear axle bounce" you will see that the Cypress caused my rear axle to oscillate excessively (in my view) when traveling over highway bridge abutments. I corrected this by installing Rancho 9000XL adjustable shocks. Some have referred to this fix as a "bandaid". I disagree. I have also added air bags and 10 ply rated tires with a maximum load rating of 3,450 pounds apiece.

With my truck equipped as described above, the truck and trailer handles in a manner very similar to the setup with the Wildcat that was more than 3,500 pounds lighter. In fact, the setup rides much more comfortably, I presume because of the Moreryde RE suspension on the Cypress

Your concern is what you can haul "safely". Certainly, one element of an analysis of "safe" towing is a review of a manufacturer's load ratings. However, I disagree with the proposition that a person cannot haul "safely" if they are close to or exceed one or more of the manufacturer's ratings. Look at the GAWR for example. As I noted under the thread "How to stop rear axle bounce", my 06 Silverado has a rear GAWR of 6,084, which is exactly twice the rating of the original tires that were rated at 3,042 apiece. If you research federal transportation regulations you will find that these regulations prohibit a manufacturer from selling a truck with tires rated any lower than the GAWR. Two Chevy dealer truck managers have told me that the 2500 and the 3500 have the same rear axle, rated at 6,900 pounds. Assuming these gentlemen know what they are talking about, logic tells me that Chevy issued a GAWR of 6,084 on the 2500HD simply because Chevy did not want to spend money on higher rated tires for the 2500 model. Bottom line, after replacing the OEM tires with 10ply rated tires that together can carry 6,900 pounds, I feel perfectly safe traveling with a rear axle weight of 6,200 pounds.

I also feel very safe braking the almost 22,000 combined load I am hauling. This feeling of safety comes from having an Allison 6 speed transmission that allows me to down shift manually as I descend steep hills. I have not considered any aftermarket braking system because I have found that shifting the Allison to third gear provides very good downhill braking on even the steepest of grades. On my recent trip coming over the mountains of Montana on I-90, I needed to use my brakes very sparingly due to the engine braking.

In my opinion, when a person is considering traveling with a setup that is close to the manufacturer's load ratings, beyond insuring properly sized and maintained tires and adequate braking capability, the most important safety factors involve driver safety, not equipment.

One more thing, when you read comments/articles that state it is "illegal" to exceed manufacturer load ratings, you might want to ask the author for the source of their conclusion. I have as of yet been unable to find any law or regulation that makes it "illegal" to exceed these load ratings. If there is such a law, I certainly would like to read it, but I have yet to find it.

[RustyJC]

By extension, the same arguments could be used to justify towing a 20,000+ lb Teton Homes 5th wheel with a Ford Ranger. Where exactly does one draw the line?

The OP has a fundamental decision to make. Does he want to tow within his ratings or not? If so, we've provided the information to enable him to make the required calculations. If not, then it really doesn't matter, does it? It's just a matter of self-justification.

Rusty

[Vulcangw]

Dear Community Moderator,

It is not a matter of "self justification." It is a matter of individuals doing their own research, relying on personal responsibility, and obeying the law. To the best of my knowledge I have done so. I have never been one to blindly listen to anonymous writers on a forum. I do my research, considering all input and its sources, and make my own decisions.

And, like I have indicated several times, I have not been able to find any law that prohibits exceeding manufacturer's load limits. Trust me, if there is such a law I really want to know about it. But, notwithstanding continuous exclamations of how it is "illegal" to exceed these limits, no one can point me to the source of "illegality". I am not saying there is no such law. I am just saying that if there is one I really want to know about it, and I would hope those on this forum who are familiar with it would point everyone to it so that everyone can be best informed of all legal requirements rather than just anonymous opinions.

[RustyJC]

Like many 3/4 ton trucks towing a heavy 5th wheel, you're over your GVWR and you're over your rear axle GAWR but have made a decision (an informed one, in your own mind) to justify operation in that regime. That, by definition, is self-justification - you've justified it to yourself.

So, to my question - where does one draw the line? How many ratings is it OK to exceed, and by how much? If there are no lines, then one winds up with the Ranger towing the Teton.

Rusty

[TXiceman]

Where Rusty and I are coming from is that we are both engineers with a lot of years of design experience behind us. We routinely design and operate equipment that has operating limits which are imposed by others or limits that we set during the design. Limits will have some degree of safety factor built into them, many of which are required by laws, codes or standards. The safety factor is not meant as an area that it is OK to operate the equipment for any extended periods of time. It is meant to be used to take you into an off-design condition which may take you slightly beyond the normal conditions and still not harm the equipment. Continued operation over the limits is often detrimental to the equipment as well as can endanger the safety of people around the equipment.

I cannot tell any one to knowingly operate any equipment beyond it's limits. Here on iRV2 we provide the necessary information to people and help them evaluate the situation. Beyond that, it is up to the individual to justify to himself, if he wants to operate equipment beyond it's rated duty.

Ken

[450Donn]

To TX and Rusty,
While we try to provide factual information or information from personal experiences like everyone has mentioned it is up to the individual to determine what is safe and prudent. Sadly there are far too many in the RV community that have no design/engineering experience but feel that they are smarter or more educated than the people who design a product. Is it stupidity? or Ignorance? I don't know and am not going to call people that publicly. However it is in their best interest to stop the self justification process and look at the purely logic standpoint. If they do not know for sure, then common sense should dictate to err on the side of caution. And there is at least one place where you will be cited for towing over the manufacturers GVWR numbers. BC Canada! So it has started, and surely will continue to grow across Canada and probably the USA in the future. So why fight it?

[ISLAPP]

Truck manufacturers spend alot of money on advertising showing how their truck is better than the other guys. They talk about horse power, fuel mileage, resale value, maintenance and PAYLOAD and TOWING ratings, among other things.
When trying to justify being over weight, why does a person even bother stating what the trucks rating is versus the actual weight? If one is so sure that they are being safe with their set up, why even bother to look at the trucks advertised numbers. After all, isnt what is being said is that the manufacture either doesnt know what a safe number is or is being too conservative for some reason and so we will just ignore them and do what we think is right and safe.

Now, I dont know if there is a "law" or not forbidding one to exceed those numbers. There is one for commercial trucks so I would not be surprised if there isnt one for us. Get in an accident and get a smart lawyer for the other guy and I guess you see. But, quite frankly, I dont care if there is or isnt a law. I'm just glad that most of use prefer to make our decisions based on the numbers that are provided by those manufacturers.

At the end of day, each person decides what is best for them. In the weight of the truck, the speed they drive, or whatever.
And this argument has gone on for years and will continue to do so.
Mike

[Vulcangw]

Here is an interesting twist. Chevy's website for its 2009 model 2500 shows a "spring capacity - rear" of 6,084 pounds, but an "axle capacity - rear" of 6,900 pounds. Since in my case with my 06 model the stock tires were rated at 3,042 apiece, I presume that the GAWR of the 09 model is, like mine, 6,084.

http://www.chevrolet.com/vehicles/2009/silverado2500hd/features.do?styleIds=301077^301078^301079&tab=tabH ighlights

Here is a question from an engineer and attorney to two design engineers - If only "stupidity" and/or "negligence" (as Donn seems to suggest) would lead someone to modify a truck's suspension, what is the point of Chevy informing the consumer/operator of the capacity of the axle?

[450Donn]

General Motors or any manufacturer for that matter will never tell anybody to exceed any capacity. when they talk about axle ratings, tire ratings, spring ratings or any other rating it is intended for that component ONLY. Just like the door post sticker rating. That is for the entire vehicle. While in most places that number is meaningless, the manufacturers are mandated by the federal government to afix that sticker which in essence certifies that the vehicle in question will meet all federal safety/handling/braking standards up to that weight. The truck divisions are so market driven, and if as most people want to believe the numbers are meaningless why not simply do away with the "3/4 ton" rating all together and simply sell a truck that is rated to carry 9900 pounds only? In other words sell one product which is what today would be called a 1 ton SRW. If as most want to try and claim the trucks are identical it makes no market sense to sell two different ratings for the same product does it?
This debate has raged for as long as I have been a member of these boards. And I at one time was one of those that towed overloaded. After towing the exact same trailer with a properly equipped and designed truck I finally understood how stupid I was towing what I did. If you think I am blowing smoke, here are the numbers I towed with a 2500HD Chevy
Truck ready to camp 7500 pounds minus trailer
Truck hitched 10,500 pounds
Trailer hitched 10,350 on the axles
People are free to do what they want, This is after all still a semi free country. However common sense needs to prevail over pride at some point.

[Vulcangw]

Donn, maybe I am stupid (as you have suggested) because I sure as heck didn't understand your last post. The question (I thought) was simple. Stated another way - If Chevy says its rear axle as a capacity of 6,900, but it's rear springs have a capacity of only 6,084, what is wrong with modifying the springs (and changing to stronger tires) in order to increase their capacity as long as one does not exceed the rear axle capacity when loaded? I am not expecting an answer at this point, although I certainly would appreciate a good one. If I am truly missing something of importance I honestly want to know it.

I recall when my Dad had a 1959 Ford that squatted too much for his tastes when he loaded it. I am sure this is way before there were any federal requirements to post weight limits. His solution to the squat was to take off his leaf springs, and take them into a local spring shop to have an additional leaf added. Worked like a charm. Does the advent of federal posting requirements all of the sudden turn such a seemingly intelligent action into a stupid one?