Chevy/GMC Duramax

[SteveH]

There seems to be thread after thread about Ford Diesel trucks, some good (the new ones and the old 7.3L) and some not so good (the inbetween ones 6.0 and 6.4L). Time will be the absolute judge of the new ones.

Anyway, enough about Fords, last year I bought a used '08 GMC 3/4 ton Duramax with 50,000 miles on it, have put about 30,000 miles on it (about 16,000 towing), and the thing just keeps on keeping on. I've not had one bit of trouble out of it, save the time I ran it "low" on fuel. (My wife and co-pilot and I still don't agree to who exactly was the one to err on that one) If anyone needs to know the procedure for priming and starting a Duramax that has been run out of fuel, just PM me and I will tell you.

Personally, I really like the truck. It is relatively quiet, smooth, gets reasonable fuel mileage, great pulling power, I think it rides excellent for a 3/4 ton, and the interior, although mine is sort of spartan, is very comfortable, especially the seats.

Sort of after the fact for me, but anyway, I thought it would be good to hear from Duramax owners about their experiences, good and bad. Do you like the truck? Would you buy another? What would you change on the truck if you could? Let's hear from the GM Duramax owners out there.

Please, this is not meant as a "bash the other brand" thread, so let's not ingage in that activity.

[noreen&sal]

Looks like you lucked out. I searched for months for a used one, but they are as scarce as hens teeth. Finally ended up with a 2000 250 PS. I think the best thing you have is the Allison trans. I guess they are scarce because the guys that get them keep them.

[jdalrymple]

Bought mine new in December of 2002. It now has 100k. No major issues. I have replaced a few small items like a front bearing hub and an axle seal but no real issues. I love it. And, at $60k for a replacement, I'm gonna drive it a while longer.

I like the strong pulling power and comfortable ride.

[Roadtoaster]

I have about 80,000 miles on my 2006 Duramax with the LBZ engine. Only problem I have had is the "Duramax rattle" which is steering sector related. Depending on the terrain, I get 12 to 13.5 MPG driving 65 MPH. It pulls our 28' easily. If I have a complaint, it is the size of the tank. 26 gallons is a bit small.

[Soyboy]

My Dmax has treated me well so far. Mine is an earlier year that may yet need the injectors replaced. I think they have moved past that issue on the newer models and the engine is proving to be very durable/reliable. Of course the Allison is fantastic. I will say on the fit and finish of interior leaves much to be desired, but it looks like the are starting to overcome that on the current generation. Hopefully the next will be another step up. I dig towing my AS with this truck, it makes the trip much more relaxing than towing with my previous gasser.

[Wingeezer]

We bought ours new in 2008, our first diesel. Not to say I wouldn't have been equally happy with Ford or Dodge, but I just love the thing! We bought a loaded model off the lot so it is pretty comfy, leather, sunroof, etc. At the time we bought it, GM's future was in doubt so I was a bit leary about buying - resale value? warranty issues? etc. but we got such I good deal on it that I couldn't resist.

Probably main reason for choosing GMC was that we had also been very pleased with our previous 1/2 ton Sierra, our first truck. I particularly liked the cab layout, and features such as the tow/haul option.

In over two years of use, (already towed with it to California and Florida) our only problem has been that the LED cab clearance lights failed. Replaced under warrantee, I bout a 6 year bumper to bumper warr. for peace of mind, especially as I knew we would be towing a heavy trailer.


Certainly would buy again. Sort of joking, but the only thing I would like is a bit more diesel sound! as a retired railway employee of 34 year, diesel sounds and smells bring back memories! I think my wife prefers the sound just as it is though!


As our first diesel, I was very happy to see how easily it starts in our Canadian winters. The glow plug light goes out in just a couple of seconds.


Brian

[BillTex]

Very pleased with our 06'. I think this engine is proving itself as dependable as a Cummins...I have heard very few complaints and the economy is pretty darn close to Cummins.
The Alli tranny is just amazing, I look forward to towing/hauling like a kid waiting to get an amusment park ride...it is that much fun.

I have never heard of a single malfunction with the Allison and am curious if anyone else has ever heard of a reliable/documented issue with this tranny?

Roadtoaster; this is a well know GM truck issue on previous gens...I brought ours in a few years back and the service Mgr didn't even let me finish my sentence...they took care of the "front end knock" right away and it has not reappeared. Our 97 truck, 01 and 04 Burbs all had the same fix...tighten the steering knuckle.

I have a passenger door power lock that is not working at this time and will have that addressed next time I am at the dealer. So 2 issues to date; steering knock (fixed) and door lock.

This truck has been bullet proof and very economical. This is our first diesel.I would (and will) buy another when the time comes...many years from now!

Bill

[pmclemore]

I've got 140,000 on my '04. Probably 110k of that is towing, including a 13k round trip to Alaska in 06.

Mine is the crew cab, dressed up LT. I reliably get 13mpg towing and 19 otherwise. I believe a couple of mpg is due to the Bully Dog tuner, which I recommend to you. If I were going to add anything, it would be an exhaust brake.

Pat

[erock53]

I have an 06' with the LBZ motor. I am just about to turn the 100k mark and have to say that I absolutely love the truck. I have a 4x4 LT crew cab. Loaded with the exception of the sunroof and factory DVD. My 2 boys (8&5) love the truck. They have plenty of room. When they get older, I think they may complain, but I have plenty of time before that happens. The truck pulls my 78 as if it were not even back there. When I'm pulling the Airstream I never exceed 70 MPH, but I can never recall it ever dropping out of 6th gear. Even in the Hills of KY. I can get 20-22 with no load and if I'm pulling the Airstream and I get around 15. I have 2 complaints. First, and probably has to do with it being a diesel, is that it takes forever to start blowing heat in the winter. I have a 5 min drive to the highway and on cold days it does not start blowing heat until I'm on the highway for 10 minutes at 65! The winter engine cover helps a little. The other complaint is that I have some sort of buzzing around 1200 RPM. I have heard a few others talk about it over on dieselplace.com but I have not been able to pinpoint the problem.

Eric

[BillTex]

Originally Posted by erock53

I have an 06' with the LBZ motor. I am just about to turn the 100k mark and have to say that I absolutely love the truck. I have a 4x4 LT crew cab. Loaded with the exception of the sunroof and factory DVD. My 2 boys (8&5) love the truck. They have plenty of room. When they get older, I think they may complain, but I have plenty of time before that happens. The truck pulls my 78 as if it were not even back there. When I'm pulling the Airstream I never exceed 70 MPH, but I can never recall it ever dropping out of 6th gear. Even in the Hills of KY. I can get 20-22 with no load and if I'm pulling the Airstream and I get around 15. I have 2 complaints. First, and probably has to do with it being a diesel, is that it takes forever to start blowing heat in the winter. I have a 5 min drive to the highway and on cold days it does not start blowing heat until I'm on the highway for 10 minutes at 65! The winter engine cover helps a little. The other complaint is that I have some sort of buzzing around 1200 RPM. I have heard a few others talk about it over on dieselplace.com but I have not been able to pinpoint the problem.

Eric

Our mileage very much on par with yours...
Agree on heat...but that is a diesel! Much larger mass of cast iron (not alumm like gasser) takes longer to heat up that mass!
We must have same truck; LT 3 pkg, crew cab, sunroof, etc...
We keep our vehicles a long time (10 yrs min) so we buy what we like...

1200 rpm? barely above idle...
Does it come from engine, tranny, wind noise?

Bill

[Bluto]

I have a 2007 LBZ diesel, long bed, crew cab, 4x4, dually. It's powerful and very capable and all that stuff, but one of the main things people don't talk about much after engine, trany, etc. is comfort. The Chevy leather seats are the best in my book. They are great for those 12 hour plus extended drives.
Since my truck had a 34 gal diesel tank, I added a TransferFlow 30gal tank in the bed that I can fill using a cap and fill hose I installed permanently thru the ARE camper top to the tank. I still have 7 feet of useful bed for all my junk I carry when camping as the extra fuel tank only takes 1 foot off the length of the bed space, and now I can go for a long time between fill ups..
I do all my own preventive maintenance(pm) on the vehicle and find that the Chevy is easy to work on and once I changed all the fluids to the synthetic brand I like, I now only have to do the pm once a year.

[pmclemore]

Love those heated seats while we wait for the heater to fire up! They'll be a required option when it is time for the next one.

Pat

[AirsDream]

I have an '08 like yours (crew cab, standard bed) ... with every available option. It's my third diesel. I find they keep improving on mileage until about 60k-75k on the clock. This one has only about 36k on it. I currently average about 12.7 towing a 23; '99 Safari ... best trip ever was 15.6 for over 500 miles. I like to tow at about 70. Solo, I average about 19, with occasional long trips over 20 mpg. ... and I'm very gentle on the throttle.

I like it fine, and yes, the heated seats are a boon in the winter. It has lots of power, obviously ... more than I need ... a couple of times with damp pavement, I've gotten a bit of rear wheelspin even fully loaded, when I got overenthusiastic on the throttle at stoplights - until the rear locker axle kicked in! So I would gladly give up some of the power and torque for better mileage, but what're ya' gonna' do?

I actually wanted to buy a Ford (I get "A Plan" pricing) but the Fords are too tall to fit under a standard 7' garage doo, so couldn't get it in my garage. That was a deal breaker.

Gripes: I'd like a larger fuel tank; I've got the standard bed, so it's got the small tank. I'd like a softer ride, and I suppose the Airstream would also, but so far no rivet / seam issues on the trailer. Exhaust brake would be useful in the mtns. And an idle-before-shutdown feature such as I've seen on some Cummins models would potentially be hepful.

[Pahaska]

Originally Posted by Roadtoaster

I have about 80,000 miles on my 2006 Duramax with the LBZ engine. Only problem I have had is the "Duramax rattle" which is steering sector related. Depending on the terrain, I get 12 to 13.5 MPG driving 65 MPH. It pulls our 28' easily. If I have a complaint, it is the size of the tank. 26 gallons is a bit small.

I have a 2007 extended cab LTX with 30,000 miles and I get about the same fuel mileage. High was 16 from Springfield, IL to St Louis. Low is about 11.5 in the short ups and downs of the Texas Hill Country.

I solved the small tank by installing a Transfer Flow 40-gallon tank in the bed.
When the main tank gets down to about 1/3, it automatically refills it to about 2/3. I put a LED on the dash to tell me when it is filling since the process is fairly slow since I am using fuel while the small pump is putting more in. I figure I have about 60 gallons usable which is good for about 2 days of 300-mile towing.

Transfer Flow also has a replacement for the OEM tank that gives a lot more range.

I have never felt the need for an exhaust brake. The Allison downshifts and holds speed down nicely in the mountains.

[Cracker]

2003 3500 GMC Crew cab, 4wd, with long bed and loaded. Injectors replaced around 50,000 under warranty. Currently about 85,000 miles on the odometer. I love the beast and it makes every trip enjoyable - towing or solo. Mostly highway miles and garaged between trips. It still looks and smells new!!!

[JBinKC]

We towed our Airstream with our '09 Silverado from Oklahomo City to Austin in a fierce 40-MPH crosswind last spring. The next week, we returned to Oklahoma City in a torrential rain. My wife's take on the two 350-mile trips: "I don't think we could've been any more comfortable." My neighbor, riding with me as I towed the Airstream back to storage, said, "Do you wish you'd bought the Duramax with the Allison?" "I did," I said.

[skykingpilot]

I just purchased a 2006 used a couple of months ago. Duramax with the Allison tranny - 4X4 loaded - dually - Crew cab. Our Company used it for towing a fifth wheel show trailer. Now has 166,000 on it and runs great. Had the injectors done right at 100K a couple of years ago. I've only put 3,000 on it so far, but looking forward to towing with it. If this is anything like your trucks... You guys have a lot of good miles ahead of you before you have anything to worry about! Have it in the body shop to have it detailed.

Have a very good buddy of mine with a new 2011 F250 Crew with the new Ford diesel. Gotta admit... if I had the dough, i would be very tempted. That has to be the nicest truck I have ever seen. Just can't stomach the thought of $50K into a truck right now... It is amazing though...

Any of you guys remember when a vehicle with 60,000 meant having a valve job - or not getting it started in the winter?

Wow, vehicles have sure improved over the years! Fun to read about all of these trucks pulling all of these amazing rigs all of those miles... Had a blast in Jackson Center a couple of years ago looking at the old trailers. Nothing like what we all enjoy today! We are all very blessed to be enjoying vehicles and rigs of this caliber!

Looking forward to a great summer of traveling and camping this year!!! Can't wait!

[Pat Conway]

Ours is a 2007 Sierra Classic (2006 Body style and LBZ engine). It's the WT model with vinyl floor and cloth seats, no power door locks and crank up windows. The dealer threw in cruise control (took off the turn signal arm and put on one that had cruise control on it and plugged it in to the steering column computer port). My wife was "honking" about the radio not having a CD player, so I replaced it recently with one I bought at a junk yard that came from a GMC Colorado that fit right into the receptacle on the dash and cannot be told from new.

The truck cost $31,000 brand new after an end of the year $5000 discount. This was the most I have ever paid for a vehicle, but it also is the best vehicle we have ever owned. It just keeps pulling, cruise control on and generally doesn't down shift out of 6th gear unless it is a really steep grade. We pull a 1988 25ft A/S TT with it that really seemed big and heavy on grades when we towed it with our 1999 Suburban 1500 with 3.73 rear end. With the Duramax we just throw in pretty much what ever we feel like. We have pulled our trailer with a generator, motorcycle, extra water, all camping supplies in the bed and loaded with antique furniture in the backseat of the cab. Duamax just kept pulling it up one hill and down the next.

It's powerful, but quiet, low enough to get into parking garages, have gotten 48,000 miles so far on the original tires.

My two cents, Pat

[Lucky Dog]

We have a 2006 Silverado shortbed crewcab with the LBZ motor and LT3 package; sunroof, leather, heated seats, etc. It is my first diesel and replaced a 2007 F150 small V8 that I thought was marginal for our AS. I love this truck. It rides a little stiffer than the 1/2 ton Ford but it was exactly what I was looking for. After doing the research I decided specifically on the Duramax/Allison combo. Didn't really need the leather, etc but couldn't pass it up when I found the truck and now am really glad it has all the extras as I intend to keep this one for a long time. Definitely a "cowboy cadillac". Doesn't have factory extended mirrors (added the slip on type that look pretty good and work OK) or roof lights. Wish it had a larger fuel tank. Can't put a tank in the bed as it has a Pace JackRabbit rollup tonneau cover. Anybody have any experience with the larger replacement tanks from Titan or Transfer Flow? Would love to have a 40+ gal tank. Had the front differential resealed because of small leak, trans cooling lines were also replaced under warranty for same reason. Dealer had "certified" the vehicle so got an additional 1 yr/12000 miles on the warranty. Currently has about 69,000 miles. Looking forward to a trip to Nashville in the spring; our first long trip with the AS. Also, the DieselPlace website is a great place for doing research on these vehicles. You can give them the VIN # of a truck you are looking at and they will get you the build sheet with specs and options the truck came with, service records, etc. I think I knew more about the truck than the salesman did (to my advantage!) when I went to check it out in person at the dealership. Great website/resource if you are shopping for a Duramax.
Rich

[SSChanger]

Bought an '03 in June 2009, absolutely love it. Got it with the LT, and the 6.6L Isuzu diesel has the Bully Dog chipset with 4 1/2" aftermarket exhaust. 130,000 miles and running strong. 14-15 mpg pulling our 30' AS at 60 mph, 22-25 without. Plenty of power, and yes, the heater seats are terrific. Wish I'd known about this truck years ago--like it better than our Lexus LS430.

Would buy another one--used, of course. Found mine 300+ miles away at Brell Auto Sales in Rogersville, MO. Bill Brell is a great guy with great trucks.

Here's the best part: This truck is actually worth $1,000 more in both retail and trade-in than it was last year. That says something!