xcmark, I've seen those load ratings for the trucks themselves. But unless it something has changed completely since 2007, the hitches that come pre-installed on the trucks aren't usually rated for the max truck tow specs. That's always been an annoyance--a new truck rated to "bumper pull" 13k+ but the factory hitch rated at 7,000 or 7.500. It wouldn't cost $40 more for the OEM truck manufacturers include the full-spec hitch on the trucks. . . but if we want to change one, we essientially have to the throw down the OEM hitch and buy a new one from scratch, getting nothing for the one that we paid for that was on the truck when it left the factory. But as a study this topic for this post, I see some of the logic: The OEM hitch may in fact be closer to the true practical load limits for safe towing. There are dozens of factors to consider.
The tow weights are reduced for extended cab trucks, and even more for crew cab trucks. My GM book takes it a step further: "Maximum trailer weight is calculated assumiing only the driver is in the town vehicle and it has all the required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle must be subtracted from the maximum trailer weight." This includes the installed weight of everything, including any goose-neck or 5th wheel hitches, safety chains, etc. All of that must be subtracted from the "maxiumum" allowed trailer weight number.
The calculation gets to be more complicated, taking into the load ratings for the individual axles. GM specifications state that trailer tongue weight should be 10-15 percent of the total loaded trailer weight--but with a catch: For example, for the 2500 HD or 3500 series trucks, the maximum tongue weight is 750 lbs for a "weight carrying" hitch. Note that 10% --no, let's split the difference between 10 and 15 and use 12.5%--12.5% of my truck's "maximum" 14,200 trailer load is a whopping 1,775 lb suggested tongue weight. Even at the minimum 10% tongue weight, this is far more than the "weight carrying" ,method you see most commonly used. The trailer tongue weight maximum is increased to 1500 lb for a 2500HD or 3500 series truck. When was the last time you saw a contractor with the weight-distributing "lift bars" installed and adjusted correctly?
The challenge keeps on going: I actually have a Putnam, I believe, weight distributing set. But the gross trailer weight rating for the assembly is only 10,000 lb.
Also note that in addition to GVWR and "maximum trailering capacity", there are also specifications for individual axles, for example, the RGAWR (Rear Gross Axle Weight Rating). It is possible--actually more often likely--that the RGAWR rating is exceeded at loads less than the maximum trailering load rating. Due to the physics & geometry of how the load vectors are applied when trailering, GM indicates that a typical trailer tongue weight of 1,000 lb can easily put more than 1,500 lb of weight on the rear axle.
This all makes my head hurt. One thing is for sure: (I learned this "one thing" trick from an attorney lol)
1a) Without a weight distributing hitch, virtually every single skid-steer or excavator trailer you see is overloaded--by a substantial amount, in many cases.
1b) Weight distributing hardware and hitch components for trailer weights > 10,000 lbs in not widely available. When you find it, it will be expensive.
1c) Even with weight-distributing hitch components, in most cases the actual "maximum loaded trailer weight" is likely to be substantially less than the biggest number you see listed in the chart, due to additional equipment, passengers, and other "non-ideal" factors.
1d) Sure, a 5th wheel or goose-neck trailer helps resolve the axle-loading/tongue weight issues. . . but with another problem, i.e. the added structural weight of the goose-neck trailer. When you see these rigs fully loaded, the weight may be distributed better between the front and rear axles, but it is highly likely that they, too, are more often than not overloaded.
Buy an excavator and enjoy it. But pick a machine (and trailer) that meets most of your needs but can be towed safely by more than one of your company's trucks. Convenience and utility is the entire point of "compact" equipment. Some of the "compact" stuff we are seeing has outgrown that adjective.
{Note to Super-Moderators: Feel free to copy or move this post to a "trailering" thread as may be appropriate.**