Chevy and GMC Duramax Diesel Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1 (Edited)
Hi all, hoping to get some feedback , suggestions for peace of mind.
we are a family of 3 . Mom , dad and 11yo daughter getting ready to go full time.
done lots of research For rig and truck set ups , towing capacity and such but honestly all a bit confusing .

we are planning on mostly boondocking And having a 4 wheeler.
So We have settled On following set up

08 keystone Raptor 5th wheel toy hauler 3712ts with solar .
UVW 12750
GVWR 16,100

04 LLY DRW 4x4 3500
According to Vin specs it shows
curb weight 6100
Gvwr. 11,500
GCVWR 23,500

if any other info/spec needed just ask Please.

last owner of theRaptor was towing it with an 05 Ford F-350 SRW with air bags , so figured we would be safe with a Duelly , but more research I do more I get concerned and wonder wether it is a safe combo.
So asking for your help and guidance With this .
would you tow with this set up ? What mods can be done to help ? What should we be on the lookout for?

thank you all in advance , looking forward to your feedback
 

·
Registered
Joined
·
672 Posts
You're probably fine, but to be sure you should go to a CAT scale with everything loaded the way you will be travelling and get the numbers on everything. Someone posted this link on another thread or forum and I saved it for reference because it's great:


From what I've learned, your biggest concern pulling this much weight is the weight capacity of your rear wheels and axle. As long as that is in check, your truck won't have a problem pulling the weight you're looking at. The motor and transmission can handle it.

If I'm wrong someone will be along soon to point out where I've misspoken.
 

·
Registered
Joined
·
328 Posts
This video covers the same issue. It’s also a LLY/LBZ DRW. Short answer. They ended up with a F450

 
  • Like
Reactions: Froggymax

·
Registered
Joined
·
1,371 Posts
This video covers the same issue. It’s also a LLY/LBZ DRW. Short answer. They ended up with a F450

I never win friends in these threads but the fact is...the "expert" in the video, doesn't really know what he's talking about. GVWRs of individual pieces of rolling stock are not enforceable for combinations (truck + trailer). What's enforceable is the GCWR, which is defined below. Other things that are enforceable are individual GAWRs and tire load ratings (neither payload nor towing capacities are enforceable; they have no legal bearing on anything). But there's no reason to add a trailer's pin weight to the truck's weight and compare that to GVWR, or compare pin weight to payload, or any of this other nonsense that every internet trailer expert insists we all do. It has no basis in the laws of man or the laws of physics.

Note that for trucks without a GCWR on their sticker (this is almost everything up until very recently), what's enforceable is the sum of the truck and trailer GVWRs.

Bottom line: unless you're exceeding the GCWR (or, equivalently for older vehicles, the sum of individual GVWRs), GAWRs, or tire ratings, you're completely legal. Pretty sure the guy in the video got rid of his truck for no reason other than internet "fame".

Also, when I hear people saying an older dually "struggles" to pull something, this has nothing to do with weight capacity (which is a function of the vehicle's frame, suspension, and tires) and everything to do with power and gearing. For people who want the truck and trailer to maintain highway speeds on steep grades yeah, they're going to need the latest and greatest machine with the most horsepower. But an old dually with 300 HP is perfectly safe pulling these heavy trailers despite having to drop down to 50 mph when the newer truck is maintaining 65 or 70. Real big rigs maxed out at 80,000 lbs going up 10 percent grades with "only" 500 HP aren't doing 65 mph either; just the nature of towing big stuff. Everyone should practice expectation management.

§ 390.5 Definitions. * * * * * Gross combination weight rating (GCWR) is the greater of: (1) A value specified by the manufacturer of the power unit, if such value is displayed on the Federal Motor Vehicle Safety Standard (FMVSS) certification label required by the National Highway Traffic Safety Administration, or (2) The sum of the gross vehicle weight ratings (GVWRs) or the gross vehicle weights (GVWs) of the power unit and the towed unit(s), or any combination thereof, that produces the highest value. Exception: The GCWR of the power unit will not be used to define a commercial motor vehicle when the power unit is not towing another vehicle. * * * * *

 

·
Registered
Joined
·
11 Posts
Discussion Starter #5
Thanks for the feedback guys .
from my calculations looks like if I max out both vehicles GVWR
11500 for truck and 16100 for camper , that will give me a total weight of 27,600lbs which will exceed the trucks published GCVWR OF 23,500.
So thinking I should just make sure to no load too much stuff on the there .
 

·
Registered
Joined
·
1,371 Posts
Thanks for the feedback guys .
from my calculations looks like if I max out both vehicles GVWR
11500 for truck and 16100 for camper , that will give me a total weight of 27,600lbs which will exceed the trucks published GCVWR OF 23,500.
So thinking I should just make sure to no load too much stuff on the there .
Is the GCWR printed on the door sticker (I believe they only began doing this on the 2020 trucks)? If not, it's irrelevant and unenforceable; an unofficial manufacturer's recommendation. In such a case you're only subject to the sum of the GVWRs.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #7
Thanks jdwarren ,, what about actually being safe to tow with it ?
is this a set up you would tow with ? I’m more concerned about The truck actually Being able to handle the camper , stopping power , up hill etc ..
 

·
Registered
Joined
·
176 Posts
I have no experience towing that heavy. I think the LLY will tow up anywhere you want to go, but as another said, you might not be able to go as fast as others. What I am concerned about is overheating. LLYs tend to get too hot going up long grades, especially when towing, and especially in hot weather.

The 2004.5 LLY has quite a long list of problems but most of them can be headed off (wiring chafing, transfer case rub, injector connectors, overheating, etc.) A big ticket problem is head gaskets, which are weak to start with, and which I think are exasperated by overheating and tuners. If you have had the '04 LLY for awhile, maybe you've already taken care of these things?

I don't think the stock brakes are very good for stopping power. When my hydrobooster started leaking, I upgraded to a 2011 hydroboost and the brakes are much better (for stopping). It might also take a little modification (enlarging the eyelet in the rod just a tiny bit). Still, you'll find the trailer brakes have to help a lot.

(added on edit in this font)
 

·
Registered
Joined
·
1,371 Posts
Thanks jdwarren ,, what about actually being safe to tow with it ?
is this a set up you would tow with ? I’m more concerned about The truck actually Being able to handle the camper , stopping power , up hill etc ..
Yes, I would tow with that configuration. Would I prefer a 2020 with 50% more horsepower and all the fun gadgets? Yeah, but last time I looked under a rock I didn't find $75k, and I suspect the same is true of you. FWIW, my rig actually breaks the laws of man (I'm over my RAWR) but I believe is not in violation of the laws of physics, as I've taken measures to ensure its safety (the rear axle itself is rated at over 10k from AAM, and I've upgraded my tires/wheels such that their capacities far exceed the load). So I am probably a little more "adventurous" in my willingness to push the boundaries than the average weight police officer on RV.net. And I am just one more face on the internet regurgitating my interpretation of the laws and my understanding of vehicles' capabilities so I encourage you to consider others' input. I have a CDL but I am not a professional driver/hauler so there are likely many folks on here who can offer a more authoritative interpretation of the laws and even some insight into actual enforcement practices (which you'll almost certainly never encounter if you're just pulling a FW/TT for personal use).

I think the things most likely to create dangerous situations are 1) worn, under-inflated, or over-capacity tires, 2) poor load distribution (i.e., too much weight toward the rear of the trailer -- this is a bigger problem with bumper-pull trailers and RVs and toy haulers don't give too much flexibility on this point anyway so I probably wouldn't worry too much about it), and 3) poor electrical connections resulting in electric brake failure or inadequate stopping power. As long as you've gone over the rig and ensured it's up to par I don't see why you should have a problem. Keep in mind the foregoing is true of any tow vehicle.

There are some LLY-specific issues (overheating, head gaskets, etc) that I'll leave other forum members to address since I have no experience with them. Since there's no way to activate any sort of exhaust brake functionality in software (to my knowledge) I would recommend at least looking at aftermarket exhaust brakes, such as this one. I think they run about $1250 but I have no idea of installation complexity (or costs, if you farm out the job). Probably not the easiest thing to install since you'll have to deal with brittle exhaust fasteners which are likely not so easily accessed in the first place. I would put this mod in the "safety" category if you plan to tow in mountainous areas. My most feared "towing nightmare" is excessive brake fade leading to a runaway truck on a twisty descent.

Something to check out on older trailers is the leaf springs. This new forum software baffles me so I'm unable to find my old threads but I posted one describing an incident on I-80 near the IN/OH border in which I had a leaf spring pack snap in half. Well, I guess it was just the final leaf that failed there when the trailer collapsed onto the rear axle/tire leaving me with the exhilarating task of locating a new leaf spring pack and installing it on the side of the interstate in 35 deg F freezing rain. Load up the trailer and look at the spring packs; if they look really flattened out or if you see anything that even might be cracking I would replace all of the spring packs with new ones that have at least one more leaf than what you currently have.
 

·
Registered
Joined
·
28 Posts
Nothing beats the accuracy of actually weighing your rig on truck scales, but another resource I often use is the Trailer Life Towing Guides. My '05 3500 DRW is rated for 12,000 bumper pull and 16,700 fifth wheel. Although that Trailer Life guide may be a little tricky reading the 2004 version for your truck, since those 6.6L-TD numbers are probably for the LB7 and not the LLY. I'd imagine your 04.5 should be close to the same as mine with the LLY, putting a 16,100 max loaded trailer within spec (although near the upper limit) from a "truck can handle it" standpoint.

FWIW the PO of my truck pulled a GINORMOUS fifth wheel toy hauler that was 14k empty, so I'm sure it was pushing 17k-18k loaded with two Harleys in the back + all the other camping stuff. He went across mountains from the Midwest to the East Coast at least annually for 10 years. I'd imagine he was technically overloaded, and I wouldn't recommend that nor do I plan to pull that heavy... but the truck apparently did it without too much complaining!
 

·
Registered
Joined
·
11 Posts
Discussion Starter #11
Ok got it . Seems like it will be a good set up overall . Thank you all very much for your feedback
. Wife and I feel much better about it. 👍
 

·
Registered
Joined
·
1,371 Posts
Ok got it . Seems like it will be a good set up overall . Thank you all very much for your feedback
. Wife and I feel much better about it. 👍
+1 to the guys who mentioned the CAT scale. Download the "weigh my truck" app for your phone and if you set up a payment method you can roll right onto the scale and get a PDF weight ticket emailed to you pretty much instantly. That's the only way to truly know your weights and for any vehicle being pushed anywhere near its capacities it's an absolute necessity. Good luck.
 

·
Registered
Joined
·
163 Posts
Some states when closed leave the scales turned on. You can check weigh yourself. Weigh each axle . Oregon and Washington leave them on and I am sure other states probably leave them on.
 

·
Registered
Joined
·
28 Posts
Weigh station scales aren't open to non-commercial vehicles in Illinois, but here in the Midwest I've had good luck finding/using truck scales at grain elevators. Go at a slow time when there's no truck traffic obviously, and you can hook/unhook as needed to weigh just the truck, just the trailer, axle combos loaded and unloaded, etc. I like to have all that data, and it's useful to determine your pin weight (fifth wheel) or tongue weight and effectiveness of weight-distribution hitch (travel trailer).

Someone posted this link on another thread or forum and I saved it for reference because it's great:

That was me. Glad you like it! :)
 

·
Premium Member
Joined
·
3,372 Posts
I have been towing an Arctic Fox 29-5T, slightly lighter than your TH for over 10 years and over 45K miles without any issues with my sig truck. I have Ryde-Ryte air bags and an 8 year old Rob Coddens tune that includes 2 tow modes with turbo brake. I drive by EGT gauge and downshift before I start up a long 7%-8% grade, I don't let the truck decide. I have pulled the Ike, the Million Dollar numerous times and many, many other passes from the PNW to the East coast. Never had any issues. I keep the stack clean and change coolant a little more often than most. Don't win any races on 8% grades but I get there without blowing up. Common sense always prevails.
 

·
Registered
Joined
·
2,571 Posts
I would upgrade to stainless brake lines over the rubber hoses then change power steering and brake fluid at least yearly. I just did 3800 miles in 10 days with wife and 3 kids with 28 foot travel trailer. Knowing I can make the rig stop and not hope it stops is a huge piece of mind when out on the road.
 

·
Registered
Joined
·
76 Posts
I pull a huge, and insanely heavy 42’ toy hauler with my LLY dually, in the mountains where I go from sea level to 10,000 feet all the time.

Most important tips to you:
1) Make sure when you’re fully loaded your rear tires aren’t squishing down and touching each other. You don’t want to have a tire fire or blow out from the rear tires touching each other. If they do touch, even just a little then you’ll need to go to the stock tire size or do what I did, I put 2” centric wheel spacers between my rear rims. I got them from a US Wheel Adapters online and out of Texas. Others sell them a lot cheaper, mine were like $300 I think, but it was not the type of life or death thing I wanted to go cheap on.

2) Air Bags on the rear axle. I went with a set from Air Lift for this truck rated for 7500 pounds (most are rated at only 5000). I have a 3” lift on my truck and the factory told me to go with Air Lifts 4” bag spacers, I should have only went with the 2” spacer, the 4’s are too tall for a 3” lift. These will give you a better ride while towing and it’ll level your truck out making it safer.My main reason for going with them was after towing one night and having every single car coming at me flashing their brights. Now my headlights no longer point up under a load.

You don’t really need all the extra expense of an onboard air compressor, in cab or remote controls, the kit comes with air lines and valves, easy install, great instructions, glue/silicone the top plates on the bags the night before, thats the only hard part, keeping the bracket hole, top plate and bags lined up to thread the top 2 bolts in during install.

They take very little air pressure to work, a bicycle pump would work just fine, it’s not like you have to raise and lower them all the time.

3) Replace the wiring connector on left (drivers) front fuel injector and the right (passenger) rear fuel injector. It’s easy to do, cheap and something the LLY is notorious for every single truck having the problem. When one or both goes bad its with no warning and you’ll be stuck where ever you’re at when they go bad. I keep an extra set of 2 in my glove box, $8 on Amazon.

4) Lift pumps, larger exhaust and all the other little things just consider optional, you honestly aren’t going to see a human noticeable difference from any of it. I have it all on my truck and maybe if I went stock one day to all of it the next there may be a difference, but slowly adding it all on over time and there’s no perceivable difference from any of it, ignore the hype.

5) Make sure your brakes are good. Replace the bearings and seals on your drive shaft, stupid cheap and easy things to replace that will other wise fail at the worst possible time. Go with the sealed U joints, they last like 100 times longer than the ones with grease zerts on them, cost is about the same.

6) Pull the wheels off your trailer, pull off the brake hubs, pull out the wheel bearings, clean and inspect all of it, pack new grease into your bearings. Trailer wheel bearings are dirt cheap, I just replace mine once a year, its easier than cleaning them. YouTube videos show you how to do all of it. Remember, trailer tires don’t usually go bad from tread wear, they go bad from dry rot. Make sure you have good load range F or G trailer (ST) tires on.

7) A lot of people like to put battery disconnects on their RV batteries to shut them off when they aren’t in it. If you have one do not turn off or disconnect your 12 volt batteries in your RV while towing it. Your emergency break away cable system uses the RV batteries to engage the trailer brakes. If the batteries are disconnected or dead this safety feature will not work.

8) Good tires on everything, spec for the proper weight or higher. The biggest cause of accidents while pulling a trailer are from highway tire blow outs. Pay attention to the speed ratings on your tires and do not tow over that speed rating. A few years ago GoodYear made a cheap tire intended for delivery trucks that only drove in town at low speeds. People were buying them and using them on RV’s because they fit and were cheap, once they started hitting highway speeds with them they were causing blowouts and accidents. Take the time to fully research and understand your tires.
 

·
Registered
Joined
·
28 Posts
^^ Awesome advice above!! Also regarding tires, make sure they are properly inflated. On my 3/4 ton Suburban, I had it down to a science based on the scale weights of my truck and trailer, tongue weight, and type of tires and factory inflation charts. There was a significant difference in inflation when I was or wasn't towing. 35psi front and 55psi when not towing, 43psi front and 73psi rear when towing. Trailer tires you almost always want to keep at max rated inflation, 80psi for most tires on larger trailers. I agree to buy one "higher level" tire than you need when you replace the trailer tires (every 4-5 years recommended, regardless of tread or outside appearance). My trailer came with D-rated ST tires from the factory, and I put E-rated tires on it last time I replaced. One more level of comfort against overloaded tires.

If you underinflate, you risk overheating and blowing tires (truck or trailer, neither is fun!) and if you overinflate, the truck will ride and handle like crap. Don't make it guesswork, do the research and know you've got it right. Carry the appropriate psi gauges and check the tires during stops. A quicker tire check tool is a laser temperature gauge, which I point at each tire to read its exterior temp when stopped. A tire losing air will be hotter than the others. Best overall equipment would be a tire pressure monitoring system (TPMS) on the trailer, that constantly reads the psi and beeps a loud warning inside the truck if a tire starts to rapidly lose air -- so you can get pulled over hopefully before a catastrophic blowout. Many fulltime or part-time RVers swear by them, but I've never gone to that level yet.
 

·
Registered
Joined
·
76 Posts
By the way, you’re already over weight, don’t add anything to make it heavier, focus on making it lighter.

Load F trailer tires = 95psi
Load G trailer tires = 110psi

Bonus: Know how to use your brake controller.
 
1 - 19 of 19 Posts
Top