Still can't decide between DRW or SRW?

tinner12002 wrote:

Bedlam wrote:
My F250 started with the 18" F350 rated wheels and camper package giving me the rear upper overload spring of the F350 plus a stablizer bar. Adding upper and lower StableLoads allowed it to carry 7000 lbs on the rear axle without excessive sag and still very good empty handling.

The additional 1000 lbs on the rear to get to 8000 lbs required more upgrades. 19.5" tires and rims (my setup had 4805 lb rated tires and 4500 lb rated rims), heavier dampening shocks (these 19.5" commercial wheels are heavier and need better dampening control) and air bags (the springs were too at their limits). Adding the heavier tires made the ride harder than stock, but my shocks were the adjustable Rancho's so dampening could be adjusted for heavy or light loads.

I'm sure the 4-link air suspension will make the ride better loaded and unloaded. I didn't go this route because I plan on upgrading to a 6000 lb truck camper that would have overloaded the Sterling 10.5's 9750 lb rating.

I'm sure if you wanted to you could throw some semi springs on it and haul a 48ft semi trailer but have you given any thought to what the axle is rated for...sure it can probably be overloaded for a while but sooner not later you'll be looking at a bearing or housing failure.

Not the person you were addressing, but he addressed that in his last paragraph (as he pointed out).

But for me, I have the same running gear as a 3500HD on my 2500HD. Same engine, brakes, and axle. Same cooling components. The suspension is a little different but I'm getting rid of the stock suspension altogether and installing suspension that is designed as a serious upgrade over the stock 1T system. And even with the 3/4T, I'm only missing a single overload leaf. With my current setup, air bags and stable loads, and only 7500 RAW, I don't think I'm exceeding the suspension capability by any stretch. That being said, I'll have completely replaced the rear suspension in a couple weeks. I'm running about 1300# over the GM RAW on my truck, which conveniently happened to be just about the capacity of 2x stock tires. My tires support 9880# per axle, so those are no longer the weakest link. My wheels support 9000# per axle, so they are a limiting factor, but still probably not the weakest link. My stock suspension is arguably still the weakest link, but as mentioned, 7500# is probably safe on it. Not wanting to take any chances, that was one of a few factors that went into me buying a replacement rear suspension rated for 12000#. The axle on my truck is rated by AAM for 10800#. So now.. I've gone from:

- Stock tire limit: 6200#
- Stock wheel limit: 6200#
- Stock suspension limit: 6200#
- Stock axle limit: 10800#

To now:

- New tire limit: 9880#
- New wheel limit: 9000#
- New suspension limit: 12000#
- Same axle limit: 10800#

Are you saying that it would be unreasonable to use 9000# as the new limit? Again, there are no other components in play that make my truck any less capable than a 3500HD SRW at this point, which has a RAWR of 7050#. And the only step from there to a dually there is the dual rear wheels, which adds tire capacity.

If you don't think it's safe to run a RAWR of 7500# on that, please provide a technical explain why. I'd really love to know. I'm under all other weights - including GCVWR - and only over the GVWR and RAWR provided by GM for a stock truck. The dually RAWR is 9375#, which is going to be whatever the lowest rated component is. With my knowledge of those components, I believe that to be the suspension. But regardless of that, I'm using an even lower figure as my maximum. That just shows that GM has enough faith in the engine, transmission, axle (I even have the same gear ratio), etc to run 9375# on it. So my 9000# (and especially 7500#) should be safe.

I do believe duallys have their place and if my trailer were much heavier I would have gone that route. Even with 19.5" tires you don't get the full capability of a dually, but within their capacities, you should get very similar performance.

For example, the dually tires on my generation of truck would be LT235/80R17/E. As a dually set, they have a total rating of 11340#. Even if I had stronger wheels, I max out at 9880#. But my sidewalls are steel belted and probably 60% thicker, and I can run at higher pressures, so I should be nearly as stable if not as stable as dual tires when running within my limits.

The requirement to spread the load over more tires seems to me that it would be exponential. It probably isn't a big deal with adding 4-5K to the rear axle, which spreads a reasonable 2-2.5K of additional weight to each of the tires. But it's going to be a huge deal with a 48' trailer with axles near the tail end that is pushing 20K+ down onto the truck. Now we're talking about adding 10000# per tire, which is much less feasible with current tire technology. Thus spreading the load either over much larger tires or many more of them. That reference is a ridiculous apples to oranges one.