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Discussion Starter · #1 ·
So I have a 2004 Silverado 3500 Dmax CCLB dually with all the cool kid mods and a built trans.

I installed a six inch lift on just the front of the truck so I could crank it down and make it level with the rear. I haul a 42ft fifth wheel with a second trailer behind it and installed 7k air bags on the truck to keep it level. Now I need new tires soon and want to go to a 35 and crank the front up some but this will make the back sit low.

With towing I don't think it would be smart to run blocks in the rear that came with the kit. Does anyone have a idea on springs to use for the rear? Could I use some lift springs for a 2500HD on the rear to help with the ride when unloaded? I assume I don't need the overloads because I have the airbags. I just figured if I was going to upgrade the springs, Id love to put something in it that would give it a little better ride when unloaded. Or am I over thinking it and a 3-4 inch block would be fine? Hitch weight on the fifth wheel is around 2800 on the high side.

I know what I "can" do but I'm huge stickler for safety and don't want to put anyone else on the road in danger so looking at all options aside from a 4 link lol

Any help or insight is appreciated.
Tire Wheel Automotive parking light Land vehicle Vehicle
 

· I'm not old, honest...
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For me, I don't know why anyone wants to fuck with an OEM suspension on a dually. They are dialed in so well from the factory and handle heavy loads with ease. Why change the COG and put a taller sidewall on a rig that is meant to tow your load safely?

I got nothin for you.
 

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Discussion Starter · #4 ·
Clearly, thanks for the input..
 

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These guys are being way to nice.

An officer, and especially an attorney won't be nearly as nice. I am going to be nice though and hope the following is not to much reading for you.


Lets start with GCVW. This number is fixed by the manufacture. It does not increase if you make more power or make suspension/frame modifications or even put 5 ton axles under the thing. The GCVW is fixed by the manufacture.

Your tires are rated for a weight by there manufacture. Normally the tires and axles are far within the limits of the GCVW. But you should run tires rated for towing and regularly check them.



The front tires and lift.
So your pulling doubles and have uneven tire wear because your camber has changed because you lifted the pile. You blow a tire, the rim hits the ground on your higher then normal COG pile, and if your lucky you don't roll from all that weight pushing you or have your doubles swing into biker or soccer mom or throw one of the trailers on it's side making the news.
Someone's going to get pictures of the idiot on the side of the road pulling doubles even if you do get very lucky and just need a new tire.

Lets say you do check your properly rated tires on a regular basis every couple of hours and while filling up. That heavy front bumper is there for a reason and I imagine it has to do with more then looks. Having front tire traction loss at times even with the bags? Changed the shocks valving and that helped maybe? At least your not running super bright LED's with your lights doing the wave over bumps to distract oncoming traffic.

Now just cause you can get away running around the thumb with doubles does not mean a officer won't love you pull you over before you get to I-80 or along US-20. I am not going to tell you the ways to avoid issues. But will say Indiana will have some fun with someone smart enough to go into their state over length. I seriously doubt it will simply be a ticket.





Not all criticism here though. Just making an attempt to wake you up with some light slapping around before you hurt someone else.

I would remove the front lift and return the suspension back to stock or slightly upgraded stock(no lift). Toss that front bumper to someone not towing. Run a factory/ish bumper with a light weight bull bar to catch the deer. Run tires designed for towing. Seriously consider downsizing your living quarters for a single toy hauler with living quarters or simply sleep in the truck/hotel pulling several piles on a flatbed. Someone on here took a 3 place. Built the front with living quarters using a old camper and still had room for 2 toys comfortably behind it. Once again watch your weights and measurements. I am sure you will pass several Cat scales in your travels. Better to find your overweight on your own 20 or so miles from the house then sitting in the back of a weigh station a couple hundred miles later.
 

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Discussion Starter · #8 ·
I appreciate the advice. For what its worth,

I have the double R license required to pull doubles and could easily get a CDL if needed.

I know Michigan is much more relaxed on triple towing. I have triple towed out of state all the way down to Georgia and was a little nervous as not all states are as relaxed on it.

Michigan law says no more than 75 feet. Im roughly 63.5 feet from truck bumper to trailer bumper so depending on which trailer I use. Im about 75-77 feet. So im right there.

GCVWR is 22k for the truck. Truck is 7200ish and camper is 12,500 dry. Add 1,000 for people and gear. Still plenty of weight for a second trailer with a golf cart, quad, etc.

The lift is a 6 inch cranked down to about a 3 inch with Bilstein 5150 and air bags in the rear. Its maybe a 3.5 inch lift above stock ride height. I would go up maybe another inch.

As for tires, any E rated or even a D rated tire would be rated for well more than I need with four tires in the rear.

The COG is raised but this is also a DRW truck with a wide track width and does not sway what so ever. Another 1-1.5 inches is not going to compromise safety imo. A srw truck is a different story.

I do agree with the tire blow out as I dont run the big bro rims. Blow outs are something I will have to take into play.

Also the lights are not bright at all and are aimed just right. The brightness in the picture is the DRL camera glare. Even the cab lights look ridiculously bright lol.

None of this matters now! Truck snapped the the crank over the weekend in Traverse City 3+ hours from home pulling the fifth wheel so its down for the winter while I save my pennies.
 

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Discussion Starter · #11 ·
From what i've read its a common issue with the Duramax. They're designed to fire cylinder 1 and 2 simultaneously putting a lot of stress on the crank, more so under heavy load. They make an cam that changes the fire order (with additional tuning and pcm pinning) that will fix that issue. I haven't torn into it yet. To much going on at work and with the kids. But hoping to pull it apart and find its just a couple broke rocker arms. I just went through the top end my self about 20k miles ago and did studs, head gaskets, etc. Praying its not the crank but setting my self up ahead of time for it. I'll be sure to post some pics here when I tear into it.
 

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I’ve added a leaf an run a smaller block before with no issues in some of my 3/4tons. My last ford have a factory rear block an so does my current dodge. I wouldn’t get stupid huge blocks but most factory owns gotta be around 4” as it is (no idea on gm drws). Could always just get a beefier rear leafs too.
my current dodge 3500 drw, has some aftermarket Dayton HD rear leafs, the Heaviest ones they make for it, it doesn’t squat for nothing! Sucks daily driving empty but doesn’t mind a heavy load. I bet the rear of the truck looks like it’s gotta 4” lift in it. I had 5 big block chevys on theback, my kid looked over an said it still rides rougher than moms truck (ram2500)
 

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Discussion Starter · #14 ·
I'm guessing you have a toooner on your duramax?
Truck has more than a "toooner" lol

Mark at Danville tuned it when I did the head gaskets, studs, 65mm turbo, 45% injectors, etc last year. The truck was built to pull. They have an issue with shearing off the pin for the harmonic balancer and causing issues with crank fractures. I'm sure the tune did not help the issue. I was pushing it pretty hard up a hill and didn't realize I had the level turned up. Had I not been towing it may have been fine. I really have no clue what happened to it but im assuming the crank. Haven't had time to touch it.
 
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