Chevy/GMC Duramax

[txhippiefish]

@rednax - you've given me lots to research, starting with some acronyms. I appreciate it!

@dscluchfc - I knew about that relationship before I did the larger wheels and tires. I underestimated the impact it would have on the economy. The Duramax has plenty of torque to turn 'em, it's just costly at the pump.

[dscluchfc]

one of my fav sayings is:
"Speed costs money, how fast do you want to go?"

Modifications cost money.....

[pmclemore]

Man, those are big-a$$ tires. Not sure they are compatible with rv'ing. But they must be great for whatever your high ground clearance activities are.

Happy trails - Pat

[dznf0g]

There are some additional calibrations for fuel, trans shift, speedo, etc. available to the dealer for changed wheel/tire sizes. They may not have one for tires as tall as yours, but ask them for the largest available. They may have to call their factory Tech Assist to get the calibration downloaded to their tool.

[TIMEMACHINE]

It has been some time since I posted here, I want to chime in on my satisfaction of my 2011 GMC Denali 2500HD with the Duramax/Allison. As many will say, all of the new diesels are good trucks, they can pull a freight train. The truck has power to spare and it is a beast with luxury.

[BillTex]

Hey time...how goes it?

I don't hang here much any more either but happened to see your post...good to see your still travelin'!

We just returned from a 6k mile trip throughout the West...beautiful!

Bill

[fman88]

My current(2008)and last truck(2003)have both been the Duramax crewcab dually 4x4. Awesome trucks. But with any truck comes problems. You expect it, you deal with it, you laugh at it and move on. My 03's warranty had just expired at 70K. Around 90K the truck started to play havoc. The motor dropped a glow plug and was playing pingpong for who knows how long. The truck started to smoke and finally ended up on the side of the road. We towed it back to my shop. I found a used engine with about 100K on it. I wasn't going to pay 7K for a reman. We swapped it over the weekend and took it camping the next with our then 87 excella 32 footer. The truck ran like a champ until we got to town. We pulled into a Walmart to stock up when all of a sudden the engine stopped running. Huh? I tried to restart but no go. Finally I got a local tow company to bring out two flatbeds. Good thing for AAA roadside assistance. We were close enough to the campground to get free towing. So up went the dually onto one flatbed and hooked up the Airstream to the other tow truck. I went online to Alldata DIY and finally troubleshooted the problem. Bad fuel filter adapter. It was leaking and wasn't keeping the fuel pressure. Got home replaced the unit and all was good. Drove the truck for another 30K until I upgraded to the 08. I bought the 08 used with about 110K on the speedo. It needed a lot of major work being that I found out later it was a ranch truck out of Texas. I went through the entire drivetrain to freshen it up. Serviced all the fluids and filters, replaced all the ebrake cables, ebrake shoes, trans cooler lines, rear discs, rear calipers, pads, axle seals, wheels studs, front discs, calipers, pads, wheel studs, tie rod ends, ball joints, swaybar bushings, powersteering pump and box and hose. Wowie Zowie what a difference. The truck drives like new. The interior is LTZ minus the DVD player and sunroof. The best feature I love is the manual 6 speed shift. As in the 03 and 08 if I put the truck into the tow mode it never fails that the truck downshifts when I don't need it. Especially on a downhill run. I was constantly punching the pedal to upshift. Now I turn off the tow mode and control the speed with the manual shift. I love it. We are now pulling an 03 safari with a slideout. What a fantastic set up. Life is good.

[TIMEMACHINE]

Originally Posted by BillTex

Hey time...how goes it?

I don't hang here much any more either but happened to see your post...good to see your still travelin'!

We just returned from a 6k mile trip throughout the West...beautiful!

Bill

Bill,

Thanks for the howdy. How was the trip? Maybe in the future we can make it to the same rally or just connect ourselves. Safe traveling!

Time (John)

[JBinKC]

Friends: My local Chevy dealer has two new nearly identical ’11 Silverados, both in LTZ trim level, both black. The first has the 6.0 V-8 for $45,900. The second has the Duramax/Allison for $50,800. I was surprised that there’s just $4,900 separating the two. That’s a sizeable amount but less than conventional wisdom has it.

[BillTex]

That was our experience also...and I am quite sure that difference could be negotiated further...When we came down to final $ for our DA...there was ~$1800 difference between diesel and 8.1l (no longer available) gasser.
The "huge" cost difference some Folks like to talk about is another "deezul myth" from Folks that haven't "been there/done that".
Kind of like the "increased cost of maintanence"...that one always leaves me puzzled...

Timemachine, yeah the trip was awesome; RMNP, Tetons, Cody, Badlands, Custer, MT Rushmore...we had a ball...then returned home to a hurricane, and spent another week living in the camper!

Bill

[Silver Otter]

Love our 08 d-max 6.6. Pulls our 30-footer fully loaded without a bit of pain, big improvement over the gasser.

[gsmithii]

Love my Duramax. Will love it more when the engine is replaced. Although that seems ominous this note is to pass along our recent experience.

Last week as we were leaving a great weekend on Skyline Drive the engine shuddered and quit.

The blow-by-blow is too long but in summary we bought our '06 Chevy in January 2010 with 57,000 miles on it. Last week we just turned 70,000. Since early in the year the dealer had been chasing a low oil pressure warning. Lots of trips to the shop where we were unable to duplicate the problem. Techs called GM Tech Central and were told that they had never seen a problem like this before. We were, of course, very interested in whether this was a warning problem or an oil pressure problem. Electrical? or oil pickup? Console? or pressure relief valve? All involved were baffled - a great reason to check the oil quantity before moving the vehicle - always! A little rpm always corrected the problem as I hovered over killing the engine if the pressure didn't recover.

We learned yesterday that we answered the question - false warning? Low oil pressure? After pulling the pan - which required pulling the engine - sheesh! - it was found that the crankshaft was cracked. Crankshaft cracked? Huh? Those hummers are bulletproof - except when they don't have oil.

We are now about to learn whether GM will honor the extended warrantee that I uncharacteristically bought.

On another note, I rented a 3/4 ton gasser to bring the trailer home. I'll sure love my Duramax with its new engine.

[Mike Leary]

As I posted earlier, the 2006 Dura seems like a bad kitty. Good luck.

[slowmover]

Very sorry to hear it, gsmithii, and I hope the resolution is quick and in your favor.

[nvestysly]

For all the folks who are fond of the Duramax and Allison combination I've created a thread for the DuraBurb. DuraBurb is a combination of Suburban (Yukon XL) along with a truck engine and drivetrain. I only wish I had an extra $50k or so - I'd buy one!

Maybe the DuraBurb and other customized, one-off rigs will gain some attention at GM and the factory will start producing a product like this. Until then, the DuraBurb looks like a good way to combine the beloved engine/tranny with the ever-popular Suburban.

Check it out on this thread.

Lucius

[AL’ UM- MONEY]

I am still weighing if this engine is worth the cost.If I towed a lot it would but occasionlly I don't know. Two questions that may have been addressed. Do the new engines have to use def fluid. When you first start one do they smoke until they warm up. This will become a difficult decision for me.

[phbarnhart]

Originally Posted by GAT

I am still weighing if this engine is worth the cost.If I towed a lot it would but occasionlly I don't know. Two questions that may have been addressed. Do the new engines have to use def fluid. When you first start one do they smoke until they warm up. This will become a difficult decision for me.

2011 on use DEF; I'm pretty sure that the 2010 was the last non-DEF year. I'm not sure about the smoking while warming up because I don't own one, but I would be shocked if they do.

[tinearpaul]

Hi:

We own a 2011 GMC Sierra Denali 3500HD SRW crew cab 4x4 and there is no smoke at start-up or operation. That's one of the bummers about these vehicles that use SCR (catalytic converters) today, the exhaust does not even smell like a diesel. After owning three Mercedes diesels from the 1970's to 1980's, I loved that smell!

As for Diesel Exhaust Fluid, the GM trucks carry around five gallons of DEF fluid. O'Reilly auto parts carries 2.5 gallons of the DEF for $12. GM's DEF is about $12 a gallon. As for use, hard to tell for "normal" driving because we mostly use the truck for towing our 04 30 ft. Classic (about 8,000 lbs. ready to go) and we get 13-14 towing up to OR and WA from Sacramento area to visit our son in Redmond, WA. With the trailer we get about 1,000 miles to gallon of DEF, probably more if we weren't towing so much. When is Seattle we went through a half tank of diesel, not towing, and got exactly 20 MPG.

Power and control is the big thing with this truck. Going up I-5 it rarely shifts out of sixth gear down into fifth. There were a few spots when it went into fourth but still better than our 02 GMC Yukon XL with the 8.1 and 4.10 rear end that frequently dropped down into third and screamed at 4,000 rpm. The mpg on those trips was never over 8 for an average.

Downhill with this truck is also great with the quiet exhaust brake. Just set the cruise at 60 and relax.

[r carl]

Kinda long but interesting.
Chevy Silverado HD2HD | Pickup Truck Comparison | Chevrolet.com

[moosetags]

We have a 2011 Silverado 3500 Duramax which uses the DEF. Wal-Mart is now carrying the 2.5 gallon bottle of Peak brand DEF for $11.50. We have bought it several times at different Wal-Marts all over the country.

Brian