LBZ reliability and capability questions

[GM Guy]

My boss hates not having a cab and chassis with an 11 ft flatbed and toolboxes, so that means he is not pleased with the pile of stuff bungie corded against the headache rack of the 8ft flatbed on his 2003 Dodge QCLB DRW Cummins 6spd. The truck pulls well, but is going to need a clutch, and maybe a tranny overhaul, so he is in a shopping mood. So he is starting to wonder about getting into a Duramax cab and chassis.

He is wondering how well a D/A pulls when pulling way over mfg suggested ratings. He hauls tractors, and many are pretty decent sized, such as today we hauled a JD 4650 with a 240 JD front end loader, and the stock 03 6 spd pulls that pretty well.

I told him my opinion on what he should get. My opinion was that he should get an 06 or 07 LBZ Duramax w/ the 6 spd allison in a 3500 DRW Reg. Cab 11ft Flatbed capable chassis cab.

The reason I recommended this is that he relies on his gooseneck pulling truck heavily, so I dont want him to deal with overheating LLYs or injectors dieing on LB7s. plus, with the heavy loads, I though a six speed ally would hold up better than the 5 speed.

Does anyone here haul heavy with their LBZ? total weight would be about 25K tops tractor and trailer, no truck, something over 30K total combination.

So, the main question I am asking, would a 06 or 07 LBZ Duramax 3500 Cab and chassis meet or exceed the expectations currently met by his 03 HPCR?

any input appreciated, thanks!

 

[THEFERMANATOR]

I'm pretty sure that an 06-07 calssic with a LBZ will be MORE than capable compared to an 03 DODGE with 305HP.

 

[GM Guy]

IMHO, horsepower doesnt matter, useable horsepower matters. Thats why I like d-max way more that 6.0 PSD. for whatever reason, even though it is a v-8, the duramax pulls pretty well as good as a HPCR.

 

[RI Chevy Silveradoman]

GM Guy:

Your right on with your suggestions. Your boss will not be unhappy with a good DMax!

 

[BoostN]

It's one of the best motors of the Duramax Generation. It would serve him well.

 

[btfarm]

The LBZ will more than meet the requirements and in most LBZ owners opinions it will do that in a "trouble free" mode. At 25k behind the truck, you're starting to top out on the chassis towing rating though so that should be looked into. You might ask about the towing issue in the towing forum here and see if those heavy haul guys pick up on it. Most I pull with my bumper hitch is around 15k and the drivetrain has more than enough omph.

 

[GM Guy]

thanks for all the input so far.

Did the LBZ have any problems or quirks that need to be watched out for?

 

[GM Guy]

I was wondering one more thing:

Sure the hp/tq levels are much higher LBZ vs 03 HPCR, but what about usable down low HP and TQ? With a big tractor on, can it maintain 65 in top OD? If it can, is it ok to run it that way, or should it be ran in the first OD (5th) when towing? if it is to be ran in the first od, what RPMS would that be running at?

 

[BoostN]

thanks for all the input so far.

Did the LBZ have any problems or quirks that need to be watched out for?

The Glow Plug controller needed reflashed, that's been a few years ago so it should be taken care of on most models.

Heaviest I've ever towed was about 9K - 10K, no problem holding hills.

 

[Unit453]

Holding 65 mph? Is that a serious question?

 

[GM Guy]

Holding 65 mph? Is that a serious question?

Well, when truck, trailer, and load total over 30K lbs, Id still wonder. but yes, a fairly dumb question. ):h

 

[BigDogYJ]

I was wondering one more thing:

Sure the hp/tq levels are much higher LBZ vs 03 HPCR, but what about usable down low HP and TQ? With a big tractor on, can it maintain 65 in top OD? If it can, is it ok to run it that way, or should it be ran in the first OD (5th) when towing? if it is to be ran in the first od, what RPMS would that be running at?

I am on 265's on stock PYO's and when GCW is at 24k I can pull level at 65 and when using T/H mode it hardly every shifted to 6th. Mainly stayed in 5th. Pulled just fine. RPM's in 5th at 65 were mid to high 1800. at 65MPH.

 

[GM Guy]

I am on 265's on stock PYO's and when GCW is at 24k I can pull level at 65 and when using T/H mode it hardly every shifted to 6th. Mainly stayed in 5th. Pulled just fine. RPM's in 5th at 65 were mid to high 1800. at 65MPH.

Thank you very much, just what i was looking for. Looks like still nice low rpms in the first OD, so running in 5th doesnt look like it would ever be an issue.

Thanks again!

 

[saratoga]

I pulled my brother's pathfinder on a trailer up to ATL several years ago now... set the cruise at about 68 and it did just fine. Downshifted a couple of times, once on the I-475 bypass in Macon and then a couple of times in the racetrack through downtown ATL. Other than that it stayed in 6th the entire trip. It averaged 14 IIRC.

 

[Coghlin]

I had an '03 and I have an '06 and also a '98 3500HD they have all been loaded to over 25,000lbs on a daily basis. The biggest thing was upgrading the tires on the 2500HDs to wider heavier load rated tires. I ran a Quadzilla chip with a 70HP tune when pulling on the 03. The 06 has an evolution programmer but I am not too impressed with this chip for pulling. It is not as smooth and gets a bit hot. Level 1 works okay. You can easily hold 60 mph pulling these weights with the Duramax. Now my 3500HD is much more capable of handling the weight but it is a dually with the 15,000GVW. Its brakes are much better than the Duramax brakes. But the 98 is not capable of holding highway speed on hills.

All of these trucks have over 250,000 kms without any injector issues or anything whatsoever. None have been to a shop for repairs except for a yearly safety check. Brakes, tires and fuel and let her rip. My Dad bought my '03 and it is over 300,000 kms and still no injector issues so I think that is a bit of a misconception of the '03s. The '03 is by far the best on fuel as well. I miss my '03 although the '06 is a bit stronger in the low end torque department and the tranny I think is better as well.

 

[Ed HD]

Our 05 LLY has pulled some enormous loads without breaking a sweat. We regularly pull a 20k water trailer with surge brakes and the truck can get it up to speed fine and stop it just as well, and this is just a 2500HD.

I saw a later 90's 454 3500 dually pulling a 4440 at our local gas station last summer. I think a duramax dually should handle a 4650 or whatever else.