Do I have this math/ understanding right?

[gattorgetter]

Got a new 2020 GMC 2500 with DMax.

Door sticker says just over 3300 for payload. Tires are 3750.

So... manufacture's say hitch weight for xx toyhauler is.... let's say 3500lbs... im guessing that is empty... now if I load 2000lb in garage... the 3500lbs hitch weight could/should be less?

[JIMNLIN]

The 2020 2500 Dmax has a 6390 rawr with 17" wheels and 6600 rawr with the 18/20" wheels.
I would say your truck has the 6600 rawr which is the lessor of a axle assy/wheel/tire or rear spring pack. On newer trucks the rear spring pack is usually the weak link.

GM specs shows the new and very high GVWR is 11550 lbs for the 2500 Dmax/18/20" wheels. This is where the higher GVWR based payload packages are overloading some 1/2 ton....3/4 ton....one ton SRW trucks low RAWR numbers on certain models when the payload is used in the bed/over the rear axles.
I wouldn't go over a 3400 lb load on the rear suspension...in the bed.
You can always upgrade the wheels or spring pack to match your tires 3700 lb capacity. The rear axle is a 11.5" AAM who rates it in the 10xxx range so the axle assy is no problem.

One thing I learned from loading several hundred long flatdeck trailers with wheeled equipment and pallets/etc...... and dozens of long GN stock trailers is there is no center point like a teeter totter for weight calculation simply because one end sits on the truck. Generally we load calves and first year lighter weight stock in the trailers front....then heavy stock (bulls or cows) over and aft of the trailers axles. Its surprising how little weight is taken off the hitch when 4k-6k lbs of bulls are placed back there.

[rhagfo]

rhagfo wrote:

gattorgetter wrote:
Got a new 2020 GMC 2500 with DMax.

Door sticker says just over 3300 for payload. Tires are 3750.

So... manufacture's say hitch weight for xx toyhauler is.... let's say 3500lbs... im guessing that is empty... now if I load 2000lb in garage... the 3500lbs hitch weight could/should be less?

Well the listed Payload is 3,300# and tires are rated at 3,750# ea.

How about the GVWR, and the rear axle rating.

That and scaled weights of the Truck with a hitch and your family.

I ask the GVWR, as GM seems to be playing games with the GVWR of their 2500's and going beyond the 10,000# max for Class2.

Once a TH is loaded for travel with toys and food, cook ware, stuff, and clothing. the pin will likely a bit more than the dry weight depending on how much stuff you carry.

So even going by tires at 3,750# you could put 7,500# on that axles if ready to tow it scales 3,500# that is only 4,000# for a dry pin of 3,500# you are very close.

I guess my big question is WHY NOT buy at least a 3500 SRW to tow a larger TH.

I need to add that when scaling the TV needs to be ready to hitch to 5er. It needs to be loaded with all passengers, full tank of fuel, all gear you carry in the TV and hitch. We lost about 1,300# off our yellow sticker payload. We went from 5,411# to 4,000# once we had the TV loaded. The sticker payload only includes a full tank of fuel & DRF and 150# driver, everything else reduces the payload!

[valhalla360]

dedmiston wrote:
That's not really such an unlikely thing. Not the theft part, but traveling without the SxS. We take trips all the time without the car in the garage. You definitely want your setup to work whether you're loaded up or not.

I'm still curious to know whether the OP is talking about a 5er or a bumper pull.

Yeah, the stolen was just to head off the excuse that "We never don't take the toys". Theoretically, you could load dirt in the back but will you remember.

I have to believe with a 3500lb hitch weight we are talking about a 5th wheel. At 15% hitch weight that would translate to a 23,500lb bumper pull.

[dedmiston]

That's not really such an unlikely thing. Not the theft part, but traveling without the SxS. We take trips all the time without the car in the garage. You definitely want your setup to work whether you're loaded up or not.

I'm still curious to know whether the OP is talking about a 5er or a bumper pull.

[Huntindog]

valhalla360 wrote:
One other issue you may run into is will you ever travel without the toys? Maybe not planned but let's say your side by side gets stolen...now you are driving back with an otherwise fully stocked trailer but nothing in the back.

If the garage is empty, now you have the empty hitch weight plus any weight from household gear stored ahead of the axles. Your empty 3500lb hitch weight jumps to 4000-4500lb.

That would be a bad thing..... But in the unlikely event it were to happen, one could always move weight to the now empty garage.
Depending on the tank layout, some shifting of weight may be possible there as well.

[valhalla360]

One other issue you may run into is will you ever travel without the toys? Maybe not planned but let's say your side by side gets stolen...now you are driving back with an otherwise fully stocked trailer but nothing in the back.

If the garage is empty, now you have the empty hitch weight plus any weight from household gear stored ahead of the axles. Your empty 3500lb hitch weight jumps to 4000-4500lb.

[rhagfo]

gattorgetter wrote:
Got a new 2020 GMC 2500 with DMax.

Door sticker says just over 3300 for payload. Tires are 3750.

So... manufacture's say hitch weight for xx toyhauler is.... let's say 3500lbs... im guessing that is empty... now if I load 2000lb in garage... the 3500lbs hitch weight could/should be less?

Well the listed Payload is 3,300# and tires are rated at 3,750# ea.

How about the GVWR, and the rear axle rating.

That and scaled weights of the Truck with a hitch and your family.

I ask the GVWR, as GM seems to be playing games with the GVWR of their 2500's and going beyond the 10,000# max for Class2.

Once a TH is loaded for travel with toys and food, cook ware, stuff, and clothing. the pin will likely a bit more than the dry weight depending on how much stuff you carry.

So even going by tires at 3,750# you could put 7,500# on that axles if ready to tow it scales 3,500# that is only 4,000# for a dry pin of 3,500# you are very close.

I guess my big question is WHY NOT buy at least a 3500 SRW to tow a larger TH.

[azdryheat]

If I did the math right, the 3500 pounds on my trailer hitch is reduced by 330 pounds if I put my 1000 pound Harley in the garage. If I put in my 1300 pound RZR the weight is reduced by 440 pounds.

Of course this was just a basic calculation that didn't figure in adding food and personal items, and other stuff.

Still, I wouldn't carry a huge toy hauler on a 2500 truck.

[noteven]

You figger this out using lever math with the center of the trailer axle group as the fulcrum for cargo behind the trailer axles. The distance from the king pin to the cargo center of gravity is the length of the lever.
Use beam or bridge math for cargo between the king pin and the trailer axles. The cargo weight is distributed to the king pin and axle group center in proportion to its distance from each.

It is possible to calculate weight distribution very accurately this way, even with a pencil and paper.

[dedmiston]

gattorgetter wrote:
Got a new 2020 GMC 2500 with DMax.

Door sticker says just over 3300 for payload. Tires are 3750.

So... manufacture's say hitch weight for xx toyhauler is.... let's say 3500lbs... im guessing that is empty... now if I load 2000lb in garage... the 3500lbs hitch weight could/should be less?

Are you looking at fifth-wheels (pin weight) or bumper pulls (hitch/tongue weight)?

[valhalla360]

If your goal is to stay within all the specs, the tires aren't really relevant (assuming they are not lower rated replacements from OEM). The manufacturer already accounted for them with the playload figure.

Yes, loading the garage will reduce the pin weight but probably not as much as you might hope.

As mentioned, if the pin is 21ft ahead of the axles and the CG of the toys is 7ft behind the axles, your 2000lb of toys will only take around 660lb off the pin weight...except anything you load ahead of the axles will add weight back onto the pin. So unless you run empty except the toys, don't expect the pin weight to go down by any appreciable amount.

Another issue...Unless you are a 150lb driver in an otherwise empty truck, you already used some of your payload. Wife, kids, dog, firewood, tool box, hitch, etc..all count against the payload...So you could be looking at a remaining payload of maybe only 2500lb if you have a family of 4 and pack like normal people.

Fully loaded (with toys) you should be looking at 20-25% of the GVW of the trailer on the pin. Only way to tell for sure is to take it down to the scales fully loaded with family aboard and get the real weights.

[gattorgetter]

No toyhauler yet... starting to shop again..

[jdc1]

Yep. By the time you add 4 people, firewood, a cooler full of beer, exta gas for the toys....you MIGHT have 2500 pounds of payload left. What's your tongue weight again?

[fj12ryder]

gattorgetter wrote:
Got a new 2020 GMC 2500 with DMax.

Door sticker says just over 3300 for payload. Tires are 3750.

So... manufacture's say hitch weight for xx toyhauler is.... let's say 3500lbs... im guessing that is empty... now if I load 2000lb in garage... the 3500lbs hitch weight could/should be less?

Yes, it will be less, sometimes a lot less. It depends on what you're hauling in the garage. Some people have had their hitch/tongue weight drop too much and resulted in poor handling.

[nayther]

I never noticed much difference with my toy hauler loaded or empty. Remember you have to add anything in the truck to that max payload, people, gear, dogs, firewood, etc.