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

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.

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.

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 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

topjimmy wrote:
Yes you will be overweight I had a 2004 LB7 (basically the same as the 2005 LLY specs) 3500 Dually and the max as I remember was 14.5K and it did O.K. but struggled going up the bigger hills and overheated some so went and traded for a 2007 LBZ Dually and they the are rated for 16.5K and have more power and the 6 speed Allison Also do not forget LLY's had a Overheating problem because of a restricted turbo mouthpiece which can be solved pretty easy but anyway yes you can do it but you will be overloaded do yourself a favor and a least step up to a 2006-2007 LBZ Dually they are much better choice for what you are looking at

Interesting, my manual states my trailer limit is 16,500lbs. I also have the Alison trans.

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.

Whether or not I like how quickly it pulls is another topic, but it sounds like I would be ok, but with no reserve.

Yes you will be overweight I had a 2004 LB7 (basically the same as the 2005 LLY specs) 3500 Dually and the max as I remember was 14.5K and it did O.K. but struggled going up the bigger hills and overheated some so went and traded for a 2007 LBZ Dually and they the are rated for 16.3K and have more power and the 6 speed Allison Also do not forget LLY's had a Overheating problem because of a restricted turbo mouthpiece which can be solved pretty easy but anyway yes you can do it but you will be overloaded do yourself a favor and a least step up to a 2006-2007 LBZ Dually they are much better choice for what you are looking at

Thanks, everyone.

Dug up my original owners manual, and found the following within:

Max trailer weight for 6.6 Diesel Dually is 16,500lbs
GCWR is 22,000lbs
Max pin weight is 3,500lbs

GVWR for the truck is 11,400lbs, 4,800lbs front axle, 8,550lbs rear axle.

So, if max trailer weight is 16,500 and GCWR is 22,000, does that mean my truck weighs 5,500 "dry"? Seems light to me.

And I assume that GCWR would include people on board, so how can anyone even be in the truck with a 16,500 trailer attached? That would mean the truck is even lighter than 5,500lbs, right?

Confused.

Certification/Tire Load Label Information on pg. 8

12,000# MAX Tow rating------22,000# GCVWR (Pg. 33)

Pages 1-50 good info
fifthwheelst.com/documents/gmc/2004_gmc_sierra_owners.pdf2004 GMC Sierra 3500


MAX Tow Rating is derived using a BASE Model with 150# driver and 20# cargo

Actual weight of truck loaded up camp ready (passengers, stuff in truck, stuff in truck bed, hitch and pin weight) deducted from GCVWR is what the actual max tow is....provided you do not exceed trucks RAWR/Rear Tire Max Load Ratings

Wet pin weight is at minimum 20% of actual trailer weight.


Example:
My 07 3500 SRW is rated at MAX Tow of 16,300 with GCVWR 23K
I tow a 14K 5vr (Scaled weight 13,873#) which puts truck right at RAWR, under Rear Tire Max Load Rating and under GCVW

Any heavier 5vr and I would exceed RAWR
My GCVWR 23,000 minus GVWR 7980 ==== max tow 15020 but I am AT RAWR with just under 14K 5vr.

Our 08 in Sig is rated at 15500 FW towing. I'm at 14600 lbs and it tows great.

Sad to say your 2004 is maxed at 14,900 pounds but none of the other truck makers were any better. If you were to upgrade to a newer truck you'r be towing more. My 2013 dually Duramax is rated for a 22,500 5th wheel and it's payload is 5,000 pounds. My 19,000 pound toy hauler puts 3500 pounds on the pin.