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Discussion Starter · #1 ·
I have a 12’ in great shape. Blackstone says my oil looks amazing at 10k mile intervals. I deleted over a year ago. Got nearly 200k on her and it runs like a sewing machine. Currently running a 30hp tow tune.

However, I feel like it’s missing some oomph when I pull even a tandem axle enclosed trailer around 5k lbs. CTS shows normal vane travel and pressures are great and holding. But I just feel trailers manhandle the truck a bit. Even an empty 20’ flat BigTex trailer.

Could it be a suspension thing? I just feel like the truck should be taking advantage of the trailer and not the other way around. Does this make sense?
 

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I have a 12’ in great shape. Blackstone says my oil looks amazing at 10k mile intervals. I deleted over a year ago. Got nearly 200k on her and it runs like a sewing machine. Currently running a 30hp tow tune.

However, I feel like it’s missing some oomph when I pull even a tandem axle enclosed trailer around 5k lbs. CTS shows normal vane travel and pressures are great and holding. But I just feel trailers manhandle the truck a bit. Even an empty 20’ flat BigTex trailer.

Could it be a suspension thing? I just feel like the truck should be taking advantage of the trailer and not the other way around. Does this make sense?
Is it a lack of power or a problem with handling? If the latter, are you running your tires at maximum pressure (at least the rear truck tires and all trailer tires)? I find running maximum pressure improves handling, and it also makes blowouts less likely.

As for suspension, it's possible that if the rear shocks are shot it would make the rear end act like a springboard. As load on the rear axle increases the natural frequency of oscillation will get lower and the amplitude will get bigger, which will make it feel like you're boating on rough water if the surface of the road has rises/dips that match that frequency at the speed you're traveling.
 

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I had a 2011 GMC 2500 company truck that the rear springs got weak on after a few years of hauling rig stuff and pulling heavy loads. Pulling a bobcat or mini-excavator got to the point of being almost scary. You may not need to go this extreme but we made my truck a 3500. Spring pack for a 1-ton is a direct bolt in and the holes are already there for the overload stops to bolt onto the frame. Handling and ride was better than I remember it when the truck was new. Look at your rear spring packs, mine went completely flat before we upgraded to the 1 ton parts.
 

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Discussion Starter · #4 ·
I’m ready for airbags for sure. With my 1700lb pin weight 5th wheel the bed squats 3”. I think the springs are a bit tired.
 

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Where does one order said 3500 springs?
The springs for my truck came from the dealer, along with the bracket thingys that bolt onto the frame for the overloads to rest on. Don’t remember what it cost, didn’t really care cause somebody else was payin for it >:)

Air bags or just a fresh set of 2500 springs may be the best answer for the OP. The truck I had was carrying a 100 gallon diesel tank, an in-house fabricated headache rack/bed rails/rear rack made out of 2” angle and square tubing, a toolbox full of heavy stuff, chains, sledge hammers, well heads, frac valves, rig parts and whatever else I could throw in it. On top of that it spent a lot of time bouncing around off-road so the more I think about it the more I think they should have just bought me a 1-ton to begin with 'dunno;haha.
 

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My rear spring pack is getting tired. I was into the overloads running empty. I installed some airlift bags and have been pleased with the results. Less squat, seems to bounce less (chucking). Cornering is much better while towing. When unloaded I run 5psi in the bags as per the manual. This keeps me out of the overloads. That along with 60psi in the rear tires makes the ride quality very comfortable. I only tow about 12k on a bumper pull toyhauler so in the big picture not much weight though.
 
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