Does anyone have experience with truck campers and know what suspension upgrades are required, if any, to carry an additional 500-600 lbs over payload capacity for trucks equipped with the factory air suspension? I know the rule is you should never go over payload capacity, but I'd like to know your experience, if anyone has tried it.
My situation is I've ordered a Four Wheel truck camper. Four Wheel is recommending Air Bags for the rear suspension, however my RAM 1500 has an air suspension, and for the leveling to work properly if the system is tripped from being over capacity, I've been advised that I should replace the factory springs with CRMs (Coil Replacement Mounts -
https://timbergroveenterprises.com/shop/09-20-ram-1500-factory-rake-stainless-sq6027994). The CRM springs hold more cubic inches of air than the factory springs. This effectively lowers the PSI required to support the truck and the truck camper load. If I didn't go with the CRMs, I run the risk of the factory air system shutting down when the PSI limit is reached. I estimate I'll be pretty close to the PSI limit fully loaded.
Hmm.
Just being REALLLLY honest? I wouldn't do it.
I had a Gen1 Rebel (4th Gen Ram 1500), and a Gen 2 Rebel.
The 5.7 Hemi is more than enough pulling power for loads - after all the 5.7 Truck powerplant was the engine of choice in the 3/4tons for many many years (albeit with different specs).
The 8speed ZF transmission is a seriously robust unit.
The E rated tires of the rebel are, again, the territory of the HD trucks, granted at lower pressures.
But it comes down to things like the cooling, axle strength, the brakes, and the stiffness of the suspension in handling the loads, as well as the weight of the truck vs the weight of what's being hauled/towed.
The Factory air suspension, while we aren't always sure about how it will fare vs cold weather? In warm weather? Is absolutely amazing. I won't repost the pictures but I've seen photos of eye-watering loads that can be levelled with the factory air suspension. But they were driving with that cargo, one way, one time. Home. Blowing a bag because of overload? Woof. Wouldn't want to pay for that repair bill, assuming the driver even kept control of the vehicle.
The braking component is not insignificant. IIRC the primary reason Ram went from the 17in to the 18in wheels, was to accommodate the bigger braking system. The problem is, when hauling heavy over spec over longer periods of time, you're asking the brakes to stop more than they're really rated to stop. That means as they get hot they're taking longer and more distance to stop. This is how you end up rear-ending some braindead millennial with a phone, because they stopped short, and your stopping distance was longer than it should have been.
PLANNING on being 500-600lbs over payload?
Stuff like that seems to quickly get rationalized in the 750 territory, as campers and trailers are notorious for weighing more than promised when delivered. It's the first thing the old timers tell the new guys, "weigh it. Do. Not. Trust. The. Estimate." It's almost always over, and that's BEFORE anything gets added to it.
Running it well over its rating for years is how you get to pre-mature parts wear and it's a safety issue dice roll on every drive.
I think halftons are pretty capable, I do think there's safety margin built into their ratings, BUT.
You can't really just add more payload to them.
They tend to be "OR" vehicles. Run them at their payload. OR if you're going over, stay under the axle ratings and bring that payload home.
OR tow at the max you figure out with the GCWR numbers and how your truck is loaded out.
Don't get me wrong, I love mine.
But with a 1,308lb payload? With me in that's like 1,100lbs.
Just as an example, I would probably trust 1,200lbs in the back with the falcon shocks in a "10 miles back home and taking the load out" environment. I would be over the door sticker, under the axle's rating, under the tires, etc. Would I do that as Plan A, and drive hundreds of mines home and to campsites with that? Honestly I wouldn't want to.
But, and I'm not sure this is precisely what you suggested but I'm using this as an example - taking that 1,300lb payload, THEN putting 500-600+lbs over the sticker right over the rear axle alone?
A ~1,950lb camper in the back?
Plus me? Plus filling it up? We just went from 1,300lbs on the sticker to +2,200lbs loaded.
Then driven a good distance back and forth. And over bumps.
Many times over the years.
No F'in way, I wouldn't do that.
A properly equipped 3/4ton HD truck would probably accommodate it just fine. No worries, headaches, drama, etc.