Center of Gravity Question

[Cannon_George]

I enjoy driving my 2004.5 Dodge Ram 2500 Quad Cab SRW Diesel 4x4 shortbox to many offroad (remote) places. The truck is equipped with airbags as well as super-springs. Stock lift.

Sold my 2,000# pop-up, now looking at a 2,600# 8'-11 hardside (non-slide) camper. The published CG (center of Gravity) for this camper is 37.5". Unfortunately, (based upon straight-edge and string lines) the distance from the rear of top front bed flange to the axle is 34". I suspect published CG is based upon dry weight but honestly don't know. Camper dealer of course says no problem.

For those with experience, how much of a detriment is this? Suggested mitigation, if any?

Thanks

[Cannon_George]

gbw, woodhog, dadwolf2, and others: Thanks for your valuable comments! It gives me more confidence. The camper I am looking at is a Northern Lite 8'-11" Queen Classic Special, not many around where I am so trying to vet this application "sight unseen." My truck has stock aluminum 17" wheels, and 285/70R 17 E-range tires.

I plan installing "smart" tire pressure sensors (with Bluetooth) to provide monitoring of air pressure.

I've read elsewhere front axle has issues. I've replaced the OEM front ball joints (upper and lower) at ~95K miles; and added grease nipples to allow better grease servicing and so far they (~75K miles) are OK. Also added Timbrens to the front spring stops. The stabilizer link bushings are shot and that is another upgrade yet to come. I've never had the "death wobble" experience but certainly aware of it.

Thanks, RV.NET for facilitating this opportunity to share experiences with others!

[dadwolf2]

I have the virtually the same truck and agree with the last two posters. With my 8' 6" camper I was near the limit of the stock tires and went with 19.5's for the extra safety margin. The only time I have ever noticed "funny" steering is when I put too much air in my air bags. Reduced air pressure so load was "in" the leaf spring and it handles like a dream.

[woodhog]

Your rear axle is rated for around 10,000 pounds, the 6000 is the tire ratings they mounted on the wheels...
We have the same truck in a 3500.. same axle.. SRW..

[gbw]

How strict do you want to follow stickers on your truck? I have the exact same truck - you can carry much more weight.

Your rear axle is rated for over 9000lbs. The limiting factor right now is your rear tires. Assuming you have the stock Dodge/Ram tires and rims at 265/70/17 and 3195lbs each. Your rear axle is now tire limited to 6390lbs. 6390lbs (two tires) - 2980lbs (rear truck weight) = 3410lbs. At this point your suspension will be a bit of a weak point but you've addressed this. You can carry 3410lbs. I'm waiting for a GVWR proponent to come out of the woods here but many will agree with me. You can probably carry a little more as the front axle will take a little weight but I really wouldn't count on that. Safe assumption is that all the camper weight will go on the rear axle.

I agree completely with your weights, my truck was within 40lbs.

If you upgrade tires and rims, you can carry much more.

Get the camper. It will carry fine. I like my similar Bigfoot.

[Cannon_George]

All: Weighed the truck. My unloaded truck scale weight is 7,280#s, with front axle 4,300# rear axle 2,980#s.

BTW the truck-camper info sheet inside my glove box said "NOT RECCOMENDED FOR SLIDE-IN CAMPERS.":(

The door stickers say this truck has GVWR of 9,000#; GAWR (Front) 5,200# and GAWR (Rear) 6,000#. If I believe the numbers then this truck has a dry payload capacity of only 1,720#s!

I am looking at a good deal on a Northen Lite, dry weight ~2,600#.

I've added supersprings, which theoretically provide rear leaf capacity equal or better than a 3500 truck capacity, which in 2004 was 3,005#s but also assumed curb weight of 6,895.

I am still concerned, is this too much camper for this truck?

Anyone out there running similar camper weights? Experience?

Thanks

[billtex]

What is the bed lg?
What does sticker in glove box read?

Ultimately a trip to the scales is in order. If you unweight the front axle...this could be an issue.

Be careful.

Bill

[bjbear]

Cannon George wrote:
Thanks all for your comments, I did not consider this in terms of percentages but it is more encouraging. With the 5.9 diesel there is already a fair amount of weight up front. I will visit scales this week and weigh unloaded front and rear axles to see what I have to work with.

You can use this calculator to get a reasonable estimate of what your rig will weigh and what your axle weights will be. http://www.visualsc.com/tc_calc.htm

[Cannon_George]

Thanks all for your comments, I did not consider this in terms of percentages but it is more encouraging. With the 5.9 diesel there is already a fair amount of weight up front. I will visit scales this week and weigh unloaded front and rear axles to see what I have to work with.

[gbsb]

I have a F 450 Ford with a Aluminum Flatbed and a 990 Arctic Fox. My CG is right over the axle, but I still have a problem with the steering and it sets high in the front. I was told that air bags would give me a lot of side to side movement. I also have hitch extension with the spare tire mounted on it and pull a 5 x 10 trailer with a Harley Tri Glide on it. I am going to try and move the spare to the front of the truck and put some batteries between the front of camper and the cab of the truck for more weight in front of the axles.

[gbsb]

I have a F 450 Ford with a Aluminum Flatbed and a 990 Arctic Fox. My CG is right over the axle, but I still have a problem with the steering and it sets high in the front. I was told that air bags would give me a lot of side to side movement. I also have hitch extension with the spare tire mounted on it and pull a 5 x 10 trailer with a Harley Tri Glide on it. I am going to try and move the spare to the front of the truck and put some batteries between the front of camper and the cab of the truck for more weight in front of the axles.

[RamTC]

I did not like the COG behind the rear axle on my 98, made for odd steering characteristics. Filling the FW tank helped as the tank was forward in my Lance 1110. Lived with the issue for years while not knowing better. When I put my AF990 on the same truck with cog forward of axle, Wow, big difference, pleasure to drive even with a 1k+ lbs. heavier Arctic Fox.

[garryk6]

I carry my 10 ft Avion on my 6.75 ft bed F350. I remodeled to move heavier items forward. With yours being only 8-9ft, on a 6 ft bed, the difference is as if you added the tongue weight of a trailer or less. If the overall weight, and axle weights are good, just pay attention to how you load, and enjoy!

Good luck!
Garry in Kodiak, AK

[wnjj]

3.5" is only 2.5% of the 138" wheelbase. This means 2.5% of the camper's weight will be removed from the front axle and added to the rear. For the 2600 lbs you listed, that's only 66 lbs. If that's dry weight you can calculate using the 2.5%, assuming the camper COG doesn't change significantly when loaded.

Many on here will say the camper COG must be at or in front of the rear axle which just isn't true. I've even posted GM's camper loading guide in the past where the COG can as far back as the tailgate so long as the relative loading of front and rear axles met a certain ratio. I think the principles would apply to any make.

Personally, I'd have no problem with it.

If you're still concerned, add a front receiver hitch for cargo and pack your heaviest stuff toward the front.