Best years for used Duramax?

[obie311]

Wife is interested in a Arctic Fox 29.5K. I think the all up GVWR is 16,600. I want something with enough torque and tow rating to not be over-stressed.

I started looking for regular 3500 DRW extended cab used trucks but they are in short supply and when you find them, they are jacked up and over-tired and inevitably owned by "Big Foot" wannabees. These trucks have so much invested in "cool mods" they cost more than a new truck.

Then I started seeing some pretty interesting deals on C4500 Kodiaks and Top Kicks w/ the Duramax/Allson combo. Relatively low mileage (60-150K) between $32-55K depending on age, trim and mileage.

Is there a best year or bracket of years for reliability in the Duramax/Allison equipment? I've read a lot on the various forums about LBY's and LBZ's but I couldn't sort out any consensus.

Appreciate any real-world advice from Duramax haulers pro or con.

Thanks,

[dennis1]

I have a LBZ, DRW, Crew Cab. Last year CHECK ENGINE light came on. Turbo was bad. Replaced turbo $2500. Mileage was 60K. No other problems. Original battery still being used. May change out just because of age. Average MPG 13 with camper and 20 without.

[502monte]

I have a 2007 LBZ with 53K on it. And no its not for sale. Only had to change the trans lines.

[RollandB]

I'm with BigSkyFamily except my LB7 is an 02. Knock on wood, no injector issues yet with the stock ones. Even knowing I'll put some $$ in the injectors one of these days, it's a great truck and just getting broke in with 104,000 on her.

[boshog]

LBZ, engine code D (eighth character in the vehicle's VIN number) is the best.

[bama2]

ditto on the lbz. 160,000 miles and still going strong. NOT FOR SALE !!!!!

[downtheroad]

I'll pile on.
We have an LBZ Duramax.

I have been approached numerous times in parking lots and campgrounds. "Is that an LBZ? What to sell it?"
Also, EVERY time I have taken it in to a shop for maintenance (any shop anywhere) I have been asked, "What to sell it?"

8th digit in the VIN is a "D" then it's an LBZ

[edatlanta]

MinnCamper wrote:
I have the 2006 LBZ and WOULD NOT give it up. I've had many offer's To sell. I have 164,000 miles and have done normal stuff and glow plugs. Good Luck!

The same here that I bought new. No offer for mine would even be considered.

[edatlanta]

MainerBob wrote:
We tow with a 2006 2500HD LBZ and love it. When we bought it from a private owner we were told, not by her, that it was the best they ever made. We bought it 3 years ago with 32K on it and it is now almost to 90K, most of it towing our Keystone Everest back and forth across the country, up and down both coasts and into the Canadian Maritimes. We've only had one annoyance, the turbo crossover pipe came apart several times and it has now been fixed thanks to a TSB from GM. We run Michelin LTX MS2 tires and are on our second set. Did I say we love it?

Good luck! Bob

I have the same truck as you and there isn't anything better IMHO. Mine is bone stock and going to stay that way. 160,000 on the clock and no issues more than normal maintenance. Today it will get a new fuel filter.

[BigSkyFamily]

"Best year" is a relative term and depends on your personal views. I have an 03. Yes it's the dreaded LB7 with the injector problems. But it's also the only generation that doesn't have a bunch of EPA mandated emissions bullcrap on it.
To some of you that might not mean anything. To me it means that in the process of turning it into a fire breathing dragon I didn't have to spend a bunch of money eliminating EGR and DPF garbage. My truck looks like a grandpa truck from the outside. Bone stock, not even aftermarket wheels, no lift, nothing. The only clue to it's performance would be the 5" tailpipe.

For my purpose the LB7 is the best generation. The injector problem doesn't matter to me, first thing I did was yank the stock injectors in favor of 30% overs anyway. The injector problems were largely blamed on poor fuel filtering and lack of sulfer for lubrication in todays diesel fuel. I've added an Air Dog fuel preperator/lift pump that filters down to 2 microns instead of the stock filter's 7 micron. I also double filter my fuel by running a 2 micron CAT filter in (the CAT filters cost half the price of the stock ones and are a better filter) the stock location. I use an additive in my fuel to gain lubricity.

270K miles on it making big power and still running strong and pulling our 5th wheel around the mountains of Montana. I'm up against the limitations of the stock bottom end. If I turn it up much more it's just a matter of time before the connecting rods spontaneously disassemble themselves. I'll wait till I feel it's tired before I go into the engine to upgrade. Which I will do long before I buy a newer truck. This one is long paid for.

These are fun trucks. Research, pick the best generation for your intended use, then order up EFI-Live for some performance/economy gains. You won't be disappointed.

[ol_Bombero-JC]

Whether it's Chevy/GMC, Ford, or Dodge diesels - the best source for info is one of the (brand) dedicated forums.

Good replies, but lots *more* info available (than on a 5th wheel forum) - by engines and years, etc......

For Chevy/GMC - go here

😉

[BobsYourUncle]

I tow with an 07 Classic LBZ and 6 speed Allison. Bought it new in August 2006.
I wouldn't give it up for any other one.
It has 297,500 Kilometers on it and the only thing I have done to the engine is one glow plug. I do however have an issue with the check engine light that I haven't fixed yet. Fuel rail low pressure code hits me when I tow in hot weather. Gotta fix that one of these days.
I have researched the best Dmax years and model and the consensus has always been the same. The one I'm driving.
It tows like a champ and no matter what I hang off the back, it pulls and handles like a dream. Mines a dually.

[greatwhitenort1]

Having had both an 05 LLY, & an 07 LBZ I would say the LBZ is superior to the LLY in that it has more torque & HP, is a quieter motor, and has the 6 speed tranny. Some of the 05's had some headgasket issues that was a screwup from GM, which was rectified with a upgraded gasket.
I now have a 15.5 LML and it is the best pulling truck, & most comfortable out of the 3 I've had, but has the emissions **** on it. I am in the process of deleting & doing a CP3 conversion which should make it bullet proof.

[laknox]

clotus wrote:
05-07 (before the body change) is the best. The 05 can be tuned to an 06, but the 06/07 had some stronger internals. I believe the 05 will yield a little better fuel mileage because of the less aggressive tune, but give up a little power. In the end 05-07 is the best Duramax, but good luck finding one for a good price, they are highly coveted. Can probably pick up a newer truck for the same price. Good luck, I wanted an 05-07 Dmax, but could not find what I was looking for and ended up with the Dodge in my sig and have been very happy with it (minus the fuel mileage).

In some states, like AZ, if you find a good early model body, you can =build= whatever engine you want and only have to meet the mfr plate's model year requirements on equipment =and= emissions. Find an '02-03 and drop an LBZ in it! 🙂 This is what I'd =love= to do!

Lyle

[laknox]

obie311 wrote:
Wife is interested in a Arctic Fox 29.5K. I think the all up GVWR is 16,600. I want something with enough torque and tow rating to not be over-stressed.

I started looking for regular 3500 DRW extended cab used trucks but they are in short supply and when you find them, they are jacked up and over-tired and inevitably owned by "Big Foot" wannabees. These trucks have so much invested in "cool mods" they cost more than a new truck.

Then I started seeing some pretty interesting deals on C4500 Kodiaks and Top Kicks w/ the Duramax/Allson combo. Relatively low mileage (60-150K) between $32-55K depending on age, trim and mileage.

Is there a best year or bracket of years for reliability in the Duramax/Allison equipment? I've read a lot on the various forums about LBY's and LBZ's but I couldn't sort out any consensus.

Appreciate any real-world advice from Duramax haulers pro or con.

Thanks,

I agree, the LBZ, 2006 and =early= 2007, are probably the best ones. I just missed an early '07 for an absolute steal and am still sick about it.

Lyle

[chiefneon]

Howdy!

We had a 2005 Chevrolet 5500 hauler. It was a great hauler for our 5er up until the time GM stopped make the MDT's. We traded ours in on a 4400 international hauler. The GM MDT truck began have problem with parts after they quit making them. The LLY was a good engine just would not have one in a MDT for those reasons.

"Happy Trails"
Chiefneon