New truck, same engine & Tranny, more or less?

[Colossus]

Howdy Folks-

 

a week and a half ago I traded in my 2013 Impala and got me a 2012 Silverado LT 2500 crew cab long bed 4X4 (non-Z71) Duramax. 67,000 miles. I had a 2008 GMC Sierra SLT Z71 crew cab long bed before the impala so essentially this is the same thing, just without the nice perks of the SLT/LTZ package, and does not have the Z71. Does have the DEF system where as the 08 LMM only had the DPF. Aside from the DEF system, is the 2012 LML D-Max essentially the same engine as the LMM? It does seem to have just a bit more power to her, although the 2012 seems to have more turbo lag (or torque management?) from a stop or downshifting vs what my 08 had.

Regardless, It is nice to be back into a truck again and I got a fair deal on it I think, and they gave me more than my Impala was worth on the trade in. Overall, I am very pleased with my buying experience from Automotive Avenues here in Lakewood Colorado.

 

Sadly though- this past Friday, the Service DEF system message came up along with the check engine light. That combination right there I knew was not good. (Check engine light should not come on unless there is an issue) I went ahead and put 2 gallons of good quality DEF in, (did not top it off) just to be on the safe side, but lights still stayed on and I had a "100 miles until 65 MPH max speed" message permanently on my DIC, and counted down. Then on Saturday, I stopped by Auto Zone and borrowed their scanner and got the code. P208B9 Redundant heather A Control Circuit/Open. Oi. Came home and researched it a bit. Appears to be the heater or control mechanism inside the DEF tank. After reading about the factory warranty in the owners manual, I called my local Chev dealer up to inquire as to if it would still fall under some sort of warranty, and was very please to hear that it would and that GM had extended the warranty in some cases for the exhaust/DEF system on these trucks. First I have ever heard about it. Made an appointment for today to drop it off to be looked at. They called me an hour or two later and said Yup, she's gonna get a new DEF tank. (which probably means all the goodies that go with it too) Had to order it from Michigan and it could take a few days. They set me up with a rental car @ Enterprise, got me into a fully loaded 2015/2016 Traverse, as some person came in earlier in the day and rented out the 4 trucks they had at that small branch location for a special event. No big deal to me, I won't need to tow or haul anything for awhile. Anyway, nice to know that I still have some warranty left with GM on this thing. I have an extended warranty also purchased from the place I got it from (it was a good deal and in researching it, it covers the things I am most worried about, and I can use it at places I want to) so I feel confident I got me a good truck over all.

 

I got my own car fax report and was pleased to see that the previous owner seemed to take very good care of her, took her to places/mostly dealerships that reported the work being done, oil changes, maintenance items, and what not. Looks like the previous owner spent a lot of time with it up in Wyoming and Colorado, lots of highway miles, but also obviously drove it off road for work, so guessing oil/gas industry, perhaps based upon how dusty/dirty the cloth seats are and the amount of dirt still on the underside even after several washes. Rust is to a minimum though, which is important to me because I know just what kind of torture you can get on Wyoming Highways from their rocks and pebbles and who knows what else they use to treat their roads in the winter. I swear I can never drive thru Wyoming in the wintertime without getting rock chips on the windshield and body of the vehicle. There are some minor things like small fluid leaks I need to address this year, and she'll need new tires, and I want to replace some worn weather stripping on the drivers door. Other than that, other mods will include getting a top/shell of some sort for the bed, some aftermarket lighting (need to upgrade the interior lights to LEDs, the regular incandescent overhead lights are way too dim!) Need to maybe see about getting the instrument cluster relit with LEDs as well, they are too dim. I'm guessing the previous owner did mostly night driving/work if the lights are as dim/worn down as they are. Also need to pick me up a few new FOBs with the remote start feature as this truck does have remote start, but the FOB provided to me by the dealer does not have the remote start button. (they gave me 1 FOB and 2 keys)

 

So as it stands now, my truck is over at the Chevy dealer waiting for the DEF tank to arrive, and then I should be in good running shape.

 

Anything else for me to look out for on the LMLs ? (I'm assuming the 2012 are LMLs? Can't remember) I'll also have the tranny serviced (with filter) and fluids all flushed/changed out this year too. I like to have a baseline.

 

Last question- What exactly does the Z71 package offer vs the stock 4X4 on the 2012?

 

Thanks

 

 

[newdude]

New 6.6L Duramax diesel and Allison 1000 six-speed combination

Supporting the new 2011 Silverado HD trucks’ greater capabilities is a new version of the workhorse Duramax 6.6L diesel and Allison 1000 six-speed automatic transmission powertrain combination. The Duramax 6.6L is more powerful and durable and the Allison 1000 is stronger and helps enable new features, including the exhaust brake system.

The Duramax 6.6L’s new and improved features include:

• 397 horsepower (296 kW) at 3,000 rpm and 765 lb.-ft. of torque (1,037 Nm) at 1,600 rpm

• NOx emissions reduced at least 63 percent over 2010 models
• Quieter operation
• High-pressure (30,000 psi/2,000 bar) Piezo-actuated fuel system for greater fuel efficiency, improved performance and reduced emissions
• Exhaust brake system that enables controlled vehicle slowdown on downhill grades without actuating the brakes
• Selective catalytic reduction after-treatment system using diesel exhaust fluid (DEF) injection to provide the best overall diesel characteristics and performance – with a range of about 5,000 miles (8,000 km) between DEF refills
• Combustion and after-treatment have been optimized to provide about 700 miles (1,125 km) between diesel particulate filter regenerations – a 75-percent improvement over the previous system and significant contributor to improved fuel efficiency, as the regeneration process requires additional fuel
• B20 biodiesel capability for an alternative fueling option
• Internal revisions that improve durability.

With nearly 1.3 million Duramax 6.6L engines produced since 2000, they have proven exceptionally durable and dependable. The internal elements that helped build its reputation are enhanced for 2011, including:

• Main bearings’ profiles changed to enhance oil film thickness
• Oil pump flow increased for increased pressure at low speeds
• The turbocharger’s oil circuit is changed to provide increased pressure at the turbo and faster oil delivery
• The connecting rods’ pin ends are modified to provide increased piston support
• New, higher-strength piston design that eliminates bushings to provide lower reciprocating weight
• An EGR cooler bypass reduces high-mileage soot deposits in the cooler and EGR circuit.

The enhanced Allison 1000 for 2011 is strengthened to handle the higher torque capability of the new 6.6L Duramax engine, while also helping improve fuel economy and providing seamless assistance with a new exhaust brake system. Greater efficiency is delivered through reduced “spin loss” – meaning, the transmission channels more of the engine’s power to the axles, allowing it to do more with less fuel.

The Allison 1000 also features driver shift control with tap up/tap down shifting and a patented elevated idle mode cab warm-up feature. Also, the tow/haul mode reduces shift cycling for better control and improved cooling when towing or hauling heavy loads. The six-speed configuration retains its two overdrive gears for optimal efficiency.

Performance with the Duramax/Allison combination is also improved over previous models, with preliminary testing showing 0-60 mph times of less than 9 seconds and quarter-mile times of less than 16 seconds in 2500HD models. That’s about 0.3-second and 0.5-second quicker, respectively, than previous models.

 

 

All the juicy details are bolded for the differences between LML and LMM. Just like LBZ to LMM, a big majority of the changes revolve around emissions regulations. The biggest mechanical changes were from the LLY/LBZ era.

 

As for what to look for? DEF. DEF system is probably the only gripe to them. Engine wise, there was some exhaust alignment issues with the downpipe.

[Colossus]

Thanks. Off the top of your head what does the Z71 package include? Also, how can I figure out what my gear ratio is?

[doverarjim]

Unless someone knows something different on a Pickup the only gear with the DMax is 3.73's. The Z71 gets different shocks and skid plates (plastic???) and a few other things that I just can't remember right now!!

[newdude]

Thanks. Off the top of your head what does the Z71 package include? Also, how can I figure out what my gear ratio is?

 

Z71 on 2007-2014 HD trucks gets 35mm deflective disk twin tube shocks, off road jounce bumpers, 33mm front stabilizer bar (smaller than Z85), skid plates (metal plates for engine and t-case), all terrain tires and Z71 decals. All HD trucks get the K47 high capacity air cleaner, Z71 or not. From 2012-2014, you could option up to the WEA Z71 appearance package which mirrored the 1500 Z71 appearance package (body colored front, handles and mirrors, chrome grille, Rancho shocks, Z71 cluster and sill plates, fog lamps and unique Z71 sticker).

 

Doverarjim is on the money for gears, 3.73 only with Duramax.