center of gravity question

On a typical 160" WB truck, moving a 4000# camper back 6" will take about 150# off the front axle and put it on the rear. A non-issue I would think, on a 4500 truck.

But I am curious about the statement that the bed on the 4500 is a foot longer than the 3500. Are these both pickup beds? Was the 3500 a short bed? Usually the extra bed length in pickup beds is ahead of the axle?

Have you ever put the 1150 on a scale ?
My 860 was just a few lbs shy of 4k empty as i weighed it at the dealers lot. I think a loaded ready to rock n roll 1150 is a tad more than 4k . Will 4500 - 5000 lbs make a difference if the COG is behind the rear axle , even on a 450 ?

it is probably cab and chassis they are 9 foot beds. at least my dads 550 is. unless it is a pickup.

hammer21661 wrote:
it is probably cab and chassis they are 9 foot beds. at least my dads 550 is. unless it is a pickup.

When going to a cab/chassis...most Folks would be putting the TC on top of the bed...so length would not be an issue...

Do you have wings you need to remove?
I think we need a pic to sort this out...

B

It's an unusual truck.

It's a 2008 Sterling, essentially a 4500 Ram, with a different tranny and nameplate. This has the 6 speed Aisin transmission (to give you an idea of how durable this is, it comes with a 180,000 mile, zero deductible warranty). It's 4 wheel drive, and the transmission even has a PTO if you want to drive an implement.
What makes it unusual is that the previous owner had it built with a custom Warner Truck body.
Normally they come with just 2 rails, and you upfit it to whatever you want: a wrecker, dump truck, ambulance, etc.
This is is cool because it looks like a 4500 on steroids. (I'll try to post some pics soon)
BUT... the bed is a 9 foot, which, frankly I didn't notice till I got it home.
Also unique is that the bed is above the rails which means there are no wheel wells. The box is a perfect rectangle, 5x9 feet, makes loading easier.
AND, the bed is a solid 7 gauge steel deck and wall system, not sheet metal. I couldn't believe it. VERY strong.
Anyway, I figure some 6inch block spacers will be fine, and I'll have an extra storage area between the cab and the TC.
Again, any input is appreciated and I will try to post some pics when I get back tonight.
I actually weighed the truck on a cat scale and it's about 9000 lbs, with 52 gallons of diesel.
The GCWR is 16,400 !!!
Even with the fully loaded AF1150 coming in at about 5k, I've still got a TON of capacity.

here's a review of the truck, which really explains a lot.

http://www.allpar.com/trucks/chassis-cab.html

I have to say, they were right, it actually drives SOFTER than my 3500, turns sharper, and is truly a pleasure to drive, even empty.

Just from a quick look and limited knowlege, since it is only 12" longer, I think if you measure you will find the distance from the rear of the truck to the axle is the same as a standard pickup (short or long, the distance is the same). If so, then no issue except the weight transfered to the front axle will be less due to the additional leverage (length between axles).

It is possible the extra space is behine the axle, however, since when loading material on the truck, the extra lenght would tend to put the material's cog behind the axle also.

Extra space when you have lots of extra capacity is always a nice thing. I see some custom doors being made into the sides to gain access under the camper winds. May not be water proof, but will be theft resistance.

With those big 11500 lb rear axle/springs on the 4500 I doubt the truck will know the difference. With a custom haul bed the rear axles weigh in the 3500-3700 lb range which leaves 7800-8000 lbs for a payload. Make sure you get separate front and rear axle weights. That way you will know how much you unloaded the front axle... if any.

5000lbs at 6" behind the axle has the same effect as 750lbs on the hitch ball at 48" behind the axle.

750lbs is still within the weight-carrying limit of most OEM receivers on 2500 and 3500 trucks.

If the manufacturers don't think it's an issue on smaller trucks, then it's not an issue on your 4500.

According to the Dodge truck specs the 4500/5500 wheel base is only 1" longer than a 3500 , so I would say that your custom bed is extended 11" more in back of the axle than a standard pickup bed . That is not to say it is a problem just something to be aware of , which evidently
you are or you would not have posted the question . Take some measurements of truck and TC and get it weighed then you'll know whats going on . Sounds like a great rig .

The space in front of the camper sounds like a good place to put an extra water tank.