It is really easy to determine how much trailer you can tow. First load up the kids, dog, full fuel and head down to the scales. Get a total weight and each axle weight. If you do not have a 5th wheel hitch installed, add 150# to your truck weight. Some hitches weight more. My Trailer Saver air ride hitch weights 432#.
Now on your door jamb sticker you will find a GVWR (total) weight which is the most your truck can weigh, full loaded with the passengers, cargo, pin weight etc. Typically a 5er will have a pin weight between 17% up to about 25%. Smaller 5ers are typically to the lower end and larger 5ers can go well over 20% of the trailer GVWR.
While in the truck, get the owners manual and in the towing section or the spec pages, look for the GCWR for you specific cab, engine and axle ratio.
GVWR - loaded truck = maximum loaded trailer pin weight.
GCWR - loaded truck = Maximum loaded trailer weight.
Per the small print on all manufactures and their Towing limits, you are not to exceed any of the ratings, GVWR, GCWR and GAWR.
The manufacturers tow ratings are based on stripped model trucks, a 150# driver, partial fuel, no cargo, no options and no hitch. Every pound over this theoretical base weight reduces payload and towing limits by the same amount.
Speaking in a very general manner, a properly equipped 3/4 ton truck will hit the GVWR limit long before it reaches the GCWR limit and is limited to about a 32' 5er on the upper limit. You may find a few 34' 5ers that can be towed by a 3/4 ton truck.
Another issue to watch is the tire ratings on the truck. Make sure they are rated to carry the load on the rear axle. Trailer tires are another issue. Many (most) manufacturers will put on the absolute minimum tire that will barely cover the trailer weight on the axles. If you are given the choice, upgrade the tires to a higher load rating.
As for all of the 3/4 ton trucks towing 34' plus 5ers, most of them have never bother to check their weights. Then you have the group that feel there is safety in numbers. As long as more people are doing something wrong, that must make it right.
So I will not tell you that you can or cannot pull a certain sized trailer, I will explain the load ratings and how to check if you are over or under the trucks ratings. I do suggest you get the truck weighed and make your own educated decision on whether you want to tow over weight if you are over weight.
Having the right sized truck makes RVing much more fun.
Have fun with the math.
Ken
