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-   -   Why the big payload difference between 3/4 & 1 ton (https://www.airforums.com/forums/f463/why-the-big-payload-difference-between-3-4-and-1-ton-149736.html)

Wanna EB 04-23-2016 06:57 AM

Why the big payload difference between 3/4 & 1 ton
 
Based on the need to increase my payload capacity, i have begun shopping for a HD pickup. Thus far I have mostly looked at the GM trucks and am puzzled trying to understand the difference between the 2500 and 3500. I have driven both and cannot detect a difference in ride (not a full and thorough comparison though). I have carefully looked at the rear suspension and the only difference I can see is the the 3500 has an extra leaf which is "out of service" until a very heavy load is applied. The salesman says the ride is "identical". It seems strange that an extra leaf would add 1500 pounds of payload over a 3/4 ton. And, it is impossible to find detailed specs which itemize the differences. Also, the price is essentially the same. Does anyone know what the real differences are on the current model trucks?

CaptMac 04-23-2016 08:25 AM

Yes, I noticed the same thing extra leaf and stronger rims and tires
There is a couple of expert GM guys on this site maybe they will chime in

ROBERT CROSS 04-23-2016 08:31 AM

Welcome Aboard....
 
IMHO.....more important than an 'extra' spring would be the axle,(GAWR), & tire ratings.


Check the sticker & tire sidewall....our 2500 Burb.

https://i68.tinypic.com/29xcg2u.jpghttps://i64.tinypic.com/30k3c0p.jpg

Bob
:flowers:

switz 04-23-2016 08:39 AM

A careful search of the parts list may show up a different axle part number on the one ton than on the ton. Also, there are possibly different frame rails used on the 1 ton.

We installed a Kelderman level ride air bag suspension system front and rear. The rear got a pair of 5,000 pound rated air bags which were attached to the original 6,010 pound rated rear axle. That is also the rating for two of the factory installed 17" Load E Michelin LT265/70R17E tires at 70 psi. I have the tires inflated to 80 psi when towing, both front and rear.

The weak link is the rating of the axle and the tires. At 80 psi, the tires are rated for 3,195 pounds each.

While the GVW on the door label is listed as 9,600 pounds, the two axle ratings are 5,500 pounds front and 6,010 pounds rear for a total of 11,510 pounds. The loaded truck is usually around 10,500 pounds with no axle ratings exceeded. That complies with the DOT regulations, which many believe do not apply to POV use. However, if I were towing commercially, those axle limits are the regulations I would need to comply with.

overlander63 04-23-2016 09:24 AM

While I can't definitively comment on GM, I do know the sum of different parts, other than possibly tire selection, between the F250 and F350 models is the height of the spacer blocks under the rear springs. The F350 has taller spacer blocks. That's it. Any other part you can order for them is the same.

Wanna EB 04-23-2016 09:26 AM

Thanks. I will check out the axle differences on my next visit...good point.

graysailor 04-23-2016 11:32 AM

Typically the only real difference is the addition of 1 leaf spring.

amaier7771 04-23-2016 11:49 AM

I have two Silverado 2500HD's (2003 & 2007Classic), and I wanted to use it for a relatively heavy LANCE slide in truck camper, for which I was told I needed a 3500HD 1 TON pickup by numerous "experts".

I then talked to my local Chevy service department and Parts department, and was shown that the GM 2500HD and the 3500 HD have identical part numbered drive trains, same axels, differentials, brake systems and suspension(except for the extra leaf in the springs you mentioned), and different shocks. Even the SRW and DRW versions have the same floating axels, and brake parts. I only was concerned with the Duramax versions of these GM trucks. So my research and confirmation from GM only relates to the GM Duramax trucks series from about 1998 through the 2007Classic old body style.

** I have no idea if this applies to GM trucks from the new 2007 versions through present, but I am sure that a discussion with a GM service and parts department should be able to help you get the straight scoop. I am sure your sales person would arrange for you to seriously talk to the service and parts departments in order to make a sale.**

(I was also told that a Silverado 1500 and a Silverado 2500(NOT THE HD version) share the same drive train suspension parts.)

I subsequently changed out the shocks, added rear suspension adjustable Airbags, and a heavy duty rear sway bar, and the setup worked beautifully.

I sold the Truck Camper, but now haul a Polaris RZR in the bed of the 2500HD, pulling our Airstream as you can see on my Avatar.

Have fun!!!

heitkergm 04-23-2016 11:58 AM

1 ton srw (single rear wheel) trucks will have about 500 or more lbs of payload.

This is due to a different spring pack, and possibly some frame/tire/axle difference. On the GMs, anyway.

The 1 ton srw might ride stiffer unloaded. They're also harder to find. Most 1 ton pickups are duallies, with huge increase in payload (at the expense of the wider rear stance). Most GM dealers will have mostly duallies in the 1ton. All GM duallies are long beds (8 ft). The 1 ton srw are either short (6.5) or long beds.

Unless you really need the extra payload, a 3/4 ton should do. There's a much bigger selection of them on the lot - cab config, trim level, and bed length.

mykytiukr 04-23-2016 12:03 PM

3/4 vs 1 ton
 
This question has come up frequently in different forums. The answer I have read that makes the most sense came from a dealer!!! On GM the only difference is that rear spring has one extra leaf and a wee bit bigger tire size. Same axle! Same frame! Realistically not much difference in payload. Should really only matter if pulling heavily loaded 5th wheel equipment trailers.

ROBERT CROSS 04-23-2016 12:09 PM

Remember.....add on bags only do squat, they do nothing to increase load carry capacity.
Axle and wheel/tire specs determine load. :wally:

Bob
:flowers:

TomKirk 04-23-2016 12:20 PM

In addition to rear differential, springs, brakes, tires & wheels, I believe the frame is also different. Have your local Chevy parts guy look in group 7.000 to give you specifics.

Tom

BoldAdventure 04-23-2016 12:23 PM

Believe me, when I say that spring rates can and do make an impact on the payload.

My 2500 Ram Power Wagon Laramie is the perfect example of this. The truck should have the same identical payload to a similar equipped 2500 Ram Laramie. But it doesn't because of the PW option group. The truck comes with springs that are much softer than the standard HD springs. The spring rate on the truck is great for articulation which is what you want for off-roading, but not so much for carrying heavy loads.

The regular 2500 Ram Laramie's springs are stiffer and don't' offer the same articulation offroad as the Power Wagon's softer springs.

According to one of Ram's engineers on the Power Wagon Registry, this results in them having to derate the payload of the truck by 500lbs. But if you were to swap the springs, you'd get it back instantly.

The same may be true of GM's spring rates and the additional leaf. For example, trucks with the Z71 package receive a stiffer progressive rate rear spring along with different shocks, and should have a slightly higher payload than a comparable non z71 truck.

There are a lot of variables that go into payload and towing capacity. Trucks aren't static, and various changes can alter the entire setup.

NWRVR 04-23-2016 12:27 PM

Don't know about GM but FMC F350 has the extra spring and 4" spacer blocks rather than the 2" on the F250. Also, if you are not spec ordering you will most likely find that the existing inventory for a 1 ton usually has extra options as mine did with a heavy duty service front suspension. The extra spring is noticeable by coming into play preventing rear sag as you may have on the 3/4 ton.

ROBERT CROSS 04-23-2016 01:12 PM

"Believe me, when I say that spring rates can and do make an impact on the payload."

They may make an impact....but they won't change the axle or tire/wheel capacity.

Bob
:flowers:

BoldAdventure 04-23-2016 01:34 PM

Quote:

Originally Posted by ROBERT CROSS (Post 1780796)
Remember.....add on bags only do squat, they do nothing to increase load carry capacity.
Axle and wheel/tire specs determine load. :wally:

Quote:

Originally Posted by ROBERT CROSS (Post 1780832)
They may make an impact....but they won't change the axle or tire/wheel capacity.

Pretty sure I'm saying the same thing. I'm just implying it's dynamic and that they account for the weakest link.

That's why I usually concern myself with axle and tires. The PW gets a 1 ton rear axle 11.5 AAM while the standard 2500 has the 10.5 AAM. But I get softer D rated AT tires from the factory. ;)

Take the Ram 1500, front and rear axles are rated at 3900lbs for 7800lbs total, but the truck itself is setup as GVWR 6800 - there is a 1000lbs margin built into that truck. Truck gets softer P rated passenger tires and that's the weak spot.

Wanna EB 04-23-2016 05:08 PM

Very helpful...thank you. I will do some digging at the dealership.

rostam 04-23-2016 08:10 PM

My understanding is that the sum of load capacity of front and rear axles is more than vehicle payload as the load can be unevenly distributed front and rear; similarly the sum of right and left tire load capacity is more than axle capacity as the load can be unevenly distributed right and left.

jcanavera 04-23-2016 08:58 PM

I haven't looked at pickups so I can't comment about them, but from my experience with 3/4 ton vans, I've found that back when I was looking, Ford and GM one ton vans had lower towing capacities than 3/4 ton models with the same axle and engine configurations. So it seems that the purchase of a one ton tow vehicle will require a larger engine or betterment in axle ratio to offset the additional weight of the one ton vehicle components.

When I bought my 3/4 ton van, the 6.0 liter gas and 4.10 axle has the best towing capacity for any GM van. Going to 1 ton with the same combo dropped towing capacity by 300-600 lbs. GM had no bigger engine nor anything better than the 4.10 axle at the time so a one ton was definitely a step down. Ford had a larger gas engine available at the time but mileage would definitely suffer.

As noted the only advantage I can see in going to one ton is the need for more cargo capacity or your ability to access a larger engine and better axle ratio.

Jack

dkottum 04-23-2016 09:40 PM

Quote:

Originally Posted by rostam (Post 1780992)
My understanding is that the sum of load capacity of front and rear axles is more than vehicle payload as the load can be unevenly distributed front and rear; similarly the sum of right and left tire load capacity is more than axle capacity as the load can be unevenly distributed right and left.

That would mean if we loaded our truck evenly, using a scale to ensure, it is fine to exceed GVWR as long as we don't exceed GAWR or tire load rating.. Which is what many of us believe.

It should also be noted we could overload an axle GAWR without exceeding GVWR.

I don't believe your explanation for determining GVWR is correct. Decent guess though as most people have no idea how GVWR, or the difference between factory vehicle weight and GVWR obliquely known as "payload", are determined.

Our method when Airstreaming is to load evenly, heavy stuff in front of the bed, and scale to ensure axle and tire limits are not exceeded. If it's a load of dirt for the garden, load it and drive home with extra care.


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