Coil vs leaf springs for off-road.

On the pre-coil sprung rear Dodge, er Ram, the 2500 would flex better than the 3500 simply because of the lack of upper overload springs. On the current design, I would still expect the 2500 to flex better than the 3500 because of the same reason.

For better durability, I would choose the 3500 with the leaf pack. Less moving parts, less bushings.

I disconnected the front on my '05 and was surprised at how much the stock 4-link will articulate (we're planning a family truck trip to Moab in April, vs our typical biannual dirt bike trip of just the guys). At 7900lbs and open differentials, I'm going to need all the help I can get.

I had a lengthy discussion with a person from the Northwood factory at an RV about trucks, at an RV show last weekend. Coil spring trucks were at the bottom of his list for a truck camper hauler.

Are you keeping the truck long term or just for this trip?

I'm quite sure that the coil springs will provide more articulation if neither truck is equipped with sway bars.

The leaf sprung truck will be better for hauling a camper.

If all you're going to buy is a lighter popup I'd consider a 1500 with leaf springs.

^What he said. Apples to apples spring rate, coils will help it articulate smoother and possibly with more travel.
But everything you do to haul a camper competently, is opposite of what you do to make a vehicle have greater suspension articulation.
Use coils for off road ing, leafs for hauling a TC. Tow a jeep if you want a real off roader.
Your limitation for off road with the camper won't be the springs, it will be the camper on top.
If you're thinking unload the camper for wheelin, that's great, but without an (expensive) seriously adjustable suspension like sway bar disconnects and somethin like air ride to adjust the spring rate significantly, you won't gain much. And then, you're wheelin a HD pickup which is a big tank.
And If you're not thinking extreme off road then the trucks suspension won't be a limiting factor anyway.

A rear coil spring might make sense for a light weight half ton pickup used as a grocery hauler. I would never want them for a truck that is going to haul heavy loads. There is no good way to beef up the suspension if needed. An extra leaf or supersprings might be needed, or at least timbrins or equivalent.

JimK-NY wrote:
A rear coil spring might make sense for a light weight half ton pickup used as a grocery hauler. I would never want them for a truck that is going to haul heavy loads. There is no good way to beef up the suspension if needed. An extra leaf or supersprings might be needed, or at least timbrins or equivalent.

I used to own a motorhome who was "overbuild" on delivery van chassis with front coil springs.
To compensate the overweight, the converter installed air bags, that would fit inside coil springs.
That was thing done in 1980's and I have not seen it on newer models.

All good information, thanks.

The leaf spring 3500 has the springs located outboard to the frame. The coil spring 2500 has the coil springs mounted inside the frame. Since the supporting member has a much wider stance with the leaf spring, it is going to be more stable but provide less articulation than the narrower coil spring. Problem is, while articulation is great for off-roading it isn't so great for carrying a high COG item like a truck camper. I have yet to find a place where my 3500 will go with the camper on board that I need that much articulation.

kohidad hit a good point about location of the springs, this especially applies if you add air bags too. The suspension should be under the frame, or outside of it. Never put airbags inside of the frame as this will support the truck in a more narrow stance and make it more likely to sway and lean.

The leaf springs are preferred because they are robust and stout side-to-side, where coils springs give no lateral stability. Leaf springs are an attachment point, but coils require linkage to hold the truck to the axles.
In 4Low you might get "axle wrap" where the leaf springs allow the axle* to rotate, pushing the leaf down in front of the axle, up behind the axle, but otherwise the leafs do a good job connecting the truck to the axle all by themselves. Your leaf truck still might have some linkage to help, but that is for help and not a primary support.
Thus, is a big reason to use leafs for TC.

* when I say "axle" rotate, I am really meaning the housing the axle is in, the part you can see attached to the differential; the axle itself always rotates of course ;)

For a stock truck I doubt it matters enough to really tell.
Mine has torsion bars front, leaf in the rear and does fine.

A good limited slip or locker would probably be of more use (front & rear)