Anyone towing 17k GVWR 5er with 2004 GMC Sierra 3500?

[ToddD]

Dually, crew cab, 4x4, LLY Duramax engine, Alison trans.

Very difficult to determine what tow capacity is and permissible pin weight for this model.

Can anyone comment on specs and if this generation TV is up to the task of pulling a 16.7k GVWR 5er?

Thanks.

[ToddD]

Got it, thanks for the explanation.

The more I research, the more I may be leaning towards a new 1 ton purchase. I'm most concerned over steep grade braking and being technically over weight, regarding insurance exposure.

My 04 SLE 3500 Sierra Crew Cab 4x4 is in good condition, with 64k miles on it. Now I just need to find out what real market value is. I'm in SE PA. Anyone have any idea?

[BBworkdog]

On the LLY, GM tried to improve emissions by raising EGT's (exhaust gas temperatures)the cheapest way they could. That was to reduce intake/turbo inlet diameters from 3 inches to 2.5. This raised EGT"S and reduced emissions but under significant loads these caused overheating of the engine and transmission. They also ran the diesel fuel through the engine to help cooling and added a fuel cooler into the system to try and control overheating. Every rig combination and their trip locations are going to have different problems and raise issues. When I was in California, I really got a kick out of passing Ford's and Dodges on the hills at 55 mph. It was when I went through Utah on the way to Illinois that the problems occurred, many continuous steep grades in the Rockies. As I said in my previous post, I added the AFE turbo inlet manifold and larger Banks inlet tube. I think it added 25 horsepower! The Earl's trans oil cooler was easy to install if you are a fair mechanic. Fabricating mounting brackets from aluminum stock is the hardest part, but was fairly easy. Any automatic trans used in towing can benefit by a larger cooler. The weakest link in your rig is the five speed auto, but its an Allison. Treat it right and it will serve you. Happy trails!

[ToddD]

BBworkdog wrote:
I had a 2004 2500HD crew cab shortbox and pulled a 36.5 Landmark 5er. It did much better after adding the Ride-rite air bag package which leveled it up. Handled much better. The LLY can pull it if you have fixed the LLY overheating problem. More on this on the Duramax forum if you look up LLY overheating issues. I added an AFE turbo inlet manifold, 3" Banks inlet tube and an Earl's trans oil cooler. Read the Allison owners manual on transmission operation. Its online somewhere if you didn't get one. I can understand keeping your truck if its paid for.

I added the S&B inlet, it is an LLY.. All else is stock, I suppose timbrens could be added. Hesitant to invest too heavily in it if it turns out to be struggling, at that point I'll pony up for a new 1 ton.

Never saw high trans temps hauling my 13k loaded gooseneck race trailer, is the trans cooler a weak point, too?

[BBworkdog]

I had a 2004 2500HD crew cab shortbox and pulled a 36.5 Landmark 5er. It did much better after adding the Ride-rite air bag package which leveled it up. Handled much better. The LLY can pull it if you have fixed the LLY overheating problem. More on this on the Duramax forum if you look up LLY overheating issues. I added an AFE turbo inlet manifold, 3" Banks inlet tube and an Earl's trans oil cooler. Read the Allison owners manual on transmission operation. Its online somewhere if you didn't get one. I can understand keeping your truck if its paid for.

[larry_barnhart]

ToddD wrote:
Interesting, various sources online state 23500 GCVR for dually.

Do you happen to know curb weight for this truck (not GVWR)?

Thanks.

We have the 05 3500 2wd crew cab and tow a 35 ft alpenlite. Total combined weight is 22920 lbs. Our truck has never overheating and doesn't get to the normal temp of 210. Towing up long mountains as I just did the highest engine temp was 207. I have the bigger turbo inlet and use the scanguage11. Never had to get to 5000 rpms ever going down a mountain. 3500 rpms or + a little. Our fifth is 14380 lbs . I feel your will be overloaded as we are matched for our truck and fifth. Almost 100,000 miles on the 05.
chevman

[4x4ord]

I towed a couple different rvs through BC with my 2003. The first one was a 1999 Citation double slide that weighed around 10,000 lbs. It pulled that trailer absolutely great. The next was an 03 Citation triple slide weighing in at 13000 lbs. It pulled it fine but the extra 3000 lbs proved to be too much for it on the down hills. I would put the transmission in low gear and the Duramax would rev to 5000 rpm in order to hold back the weight on 8% grades.

[burningman]

There's no way you'll be over the actual load limit of your rear axle.
It's the exact same axle as used in other trucks with higher numbers.
The truck manufacturers de-rate components like that.
Truck-camper guys run all over the country in trucks like yours with 4000+ pound campers that put nearly all their weight on the rear axle.

Brakes? Ha! Go look up the part numbers. The later ones use the exact same ones.
Your truck will work.
Go on the Duramax forums where guys really know your truck and you'll learn what the weak points are and how to upgrade them.

[wantabe351]

Yes the 5er is too heavy for your truck, but ask yourself where you plan on going and how many times a year your travels take you on camping trips of 200 miles or more. If your doing Cross Country trips or going into the Rockies, even into the mountains of VT,NH this will be hard on the truck and driver too. When your over your max weight besides the legal stuff there is the Brakes, which take longer to stop VS a 10K load.. Then pulling a 7% mountain pass thats 2miles long But heres the kicker it sets at 7,000 to 8,000 feet, wow the EGT runs very high and you see the Black smoke coming out the tail pipe and you need to drop down into the lower gears and hang out in the slow lane with the 18Wheeler..Why turbo can only pull in so much air, at that altitude the air is thinner. Theses are some issues I find, but brakes scare me, for when that car pulls out in front of you or the traffic light at the bottom of the hill turns Red....Next time out after driving for like a hour try the panic stop, the real hard stop..well did you run them over? See you can build up our trucks but its the unseen things we don't think of until it happens....So if you ride local and take a easy but be careful..So go to the scales on your next trip ALL loaded and see what you have and where your heavy-axle weight also means tire limit too.Pin weight runs around 20-25% of the 5er gross so a 17k gross is about 4,250lb pin weight plus whats in you bed of the truck( hitch,Gen,firewood,extra fuel,stuff) adds up fast now a pin of 4,600#..

[JIMNLIN]

My sticker says 8550lbs GAWR. And the truck rides quite hard at proper tire pressure, interesting. Given that the actual axle is up to the task, would the addition of Timbrens or airbags serve as the equivalent of a spring upgrade?

3500 is the mix pin weight according to the manual, if GVWR of trailer is 16,700, that would put pin weight in the mid 3000lbs range using a 20% estimate. Is there a way to measure pin weight directly? Jayco quotes 2820, which sounds low.

Bags or Timbrens will work for what your trying to accomplish although I wouldn't add anything till your actually hooked up with a road ready trailer .....then decide if the rear suspension needs help.
Actual pin weight on the rear axle can only be measured with the trailer hooked and then a re-weigh un hooked.
I doubt the DRW will have any issues carrying the dry or wet pin weight.

[lee_worsdell]

i had 04 dually with a edge chip in it towed fine. trailer was about 14500 I think back then,only issue was over heating going up the bigger hills. Rad just wasn't large enough back then temps would rise a bit.

[ToddD]

JIMNLIN wrote:
GM did have overheating issues with the Dmax LLY (??) engine . Check out some of the GM diesel websites for input on these trucks and what the fix was.....or any issue you might think of.

That's what I've learned recently. I've never seen high gauge temps, even pulling my fully loaded 40' enclosed gooseneck race trailer on a hot day, and I'd assume if EGTs were surging that high I would have seen some evidence of it. Have had the truck since new and all it does is tow duty.

Either way, I just ordered an aftermarket turbo inlet hose replacement which apparently solves this and adds some power, too. $200 is cheap insurance.

[ToddD]

JIMNLIN wrote:

Anyway, so far what I am seeing here is that as long as I am at or under 22,000lbs GCVR with a max 3500lbs pin weight, I am within spec and technically legal. I guess a trip to the scales to tell me my "regular" truck weight is next so I can see what I have left over for the trailer out of the 22k total.

Be sure and get separate front and rear axle weights. A gross weight doesn't tell you much....if your over axle/tire load limits.
Sometime in the mid '00 GM shot themselves in the foot with the DRW truck. They actually lower RAWR down to 8200-8400 lb range by using lower rated rear spring packs for a softer ride. They admitted the mistake and upgraded the whole truck in the late '00s and went with a 9375 rawr with the same AAM 11.5" rear axle. AAM give the axle a 10xxx lb rating...one tough axle.
Upgrade the rear spring packs would fix that issue.

GM did have overheating issues with the Dmax LLY (??) engine . Check out some of the GM diesel websites for input on these trucks and what the fix was.....or any issue you might think of.

My sticker says 8550lbs GAWR. And the truck rides quite hard at proper tire pressure, interesting. Given that the actual axle is up to the task, would the addition of Timbrens or airbags serve as the equivalent of a spring upgrade?

3500 is the mix pin weight according to the manual, if GVWR of trailer is 16,700, that would put pin weight in the mid 3000lbs range using a 20% estimate. Is there a way to measure pin weight directly? Jayco quotes 2820, which sounds low.

[JIMNLIN]

Anyway, so far what I am seeing here is that as long as I am at or under 22,000lbs GCVR with a max 3500lbs pin weight, I am within spec and technically legal. I guess a trip to the scales to tell me my "regular" truck weight is next so I can see what I have left over for the trailer out of the 22k total.

Be sure and get separate front and rear axle weights. A gross weight doesn't tell you much....if your over axle/tire load limits.
Sometime in the mid '00 GM shot themselves in the foot with the DRW truck. They actually lower RAWR down to 8200-8400 lb range by using lower rated rear spring packs for a softer ride. They admitted the mistake and upgraded the whole truck in the late '00s and went with a 9375 rawr with the same AAM 11.5" rear axle. AAM give the axle a 10xxx lb rating...one tough axle.
Upgrade the rear spring packs would fix that issue.

GM did have overheating issues with the Dmax LLY (??) engine . Check out some of the GM diesel websites for input on these trucks and what the fix was.....or any issue you might think of.

[topjimmy]

My 2007 LBZ per my Manual for my Dually 4WD Automatic Crew cab long bed is 16K MAX 5th wheel towing and 23.5 GCWR and remember this is with the LBZ Duramax with the new(as of 2006) 6 speed Allison and about 100 lbs more torque than your 2004 LLY, my fully Loaded 2015 40 ft Montana comes in at 15.7K so I am barely squeeking by ,if I had just had a Extended cab 2WD Dually It would be rated at 16.6K but anyway that is why I traded my 2004 Duramax Dually for a 2007 LBZ Dually to tow my 15.7K 5er but like I said my 2004 did it just fine and so would yours I was just a little overloaded and a little short on power on the bigger pulls