2006 GMC Duramax Diesel maintenance

Discussion in 'The Choo-Choo shop' started by Rich Johns, May 27, 2008.

  1. Rich Johns

    Rich Johns Platinum Level Contributor

    I recently bought an 2006 GMC 2500 truck with 6.6 litre Duramax Diesel engine and Allison trans and was wondering what you guys use for engine oil /trans fluid.
    I have changed everything to start with Shell Rotella T 15/40 regular oil and for Allison trans with GM Dextron IV.
    Howevr I would like to use Synthetic engine oil and Trans fluid so what do you guys use?
    Do any of you guys have same truck and what are you using for oils?
    Thanks in advance
    Last edited: May 28, 2008
  2. Greg Schmelzer

    Greg Schmelzer What are you looking at?!

    Rich, I use exactly what you listed. I change engine oil every 5K and the fuek filter every 10K. The fuel filter is a lot cheaper than getting an injector pump rebuilt. I may be a bit paranoid, but we also have some crap diesel here and it seems to liven up every time I change the fuel filter.

    On a side note, have you thought about 'chipping' it yet. It only took me 3 weeks to order my Bully Dog Triple Dog Downloader and an outlook pod and an A-pillar mount for the Outlook pod. When I set it on 'extreme' and spool the turbo up on a brake stand in 4 Hi, I will spin all 6 tires when I release the brake. Fuel mileage has also increased dramatically. I now get 19 mpg towing the 23' flatbed with the 4k lb 73 Century on board. On the interstate, I regularly see 24 mpg unloaded when running in 'extreme.' Mileage goes down as the power level is lowered.

  3. Rich Johns

    Rich Johns Platinum Level Contributor

    Thanks Greg
    I have not bought a chip programmer yet although there is a big range in price.
    On a recent trip empty not towing I averaged 18.5 mpg.
    What programmer would you suggest would offer best fuel econonmy or most mpg?
    My truck cuurrently has 42 K on it and from what I am told these Duramax engines do not start getting good mileage until they hit 50K and max out mpg when they hit a 100K and beyond
    What are your thoughts?
    Last edited: May 28, 2008
  4. 70 gsconvt

    70 gsconvt Silver Level contributor

    I have a 2005 Chevy with the duramax/allison combo. I change my oil every 5K miles with Rotella 5W40 synthetic (I know). Then every 10K miles I change the oil, fuel filter, air filter, and trans external filter. You can get this stuff very reasonably priced online if you buy them by the case (6 in a case).

    Here's a great web site with tons of info on these trucks:

  5. Madmax69

    Madmax69 Well-Known Member

    I have an 05. I change the oil/filter with Mobil 1 diesel, 5w-40, and the Mobil 1 filter. It's a lil hard to find, but i use that. Rotella is good also. Ditto on the fuel filter as above, I change it every 10K, and use the factory filter. I also change the Allison filter every other oil change. Don't know if that's obsessive or not, but that's what I do. Don't buy it at a GM dealer, get it right from a large truck Allison shop. Save ya major $$.

    As far as the tranny goes, but Allison Transend in it. It's expensive, but it's a synthetic tranny fluid that Allison themself recommends. Just don't crap at the price, I forwarned ya!:cool:

    These trucks are incredible chipped. I have a Predator programmer on 65hp, and a 'boost stick', have the EGR blocked, and the cat removed. With this settup I could prob run high 14's in a 7200lb truck. Be VERY careful running over a 65hp setting, the tranny won't take much more than that for long towing. None of them improve mileage very much that I have seen, what they do is screw up the mileage calculator on your dash. A quick manual calculation the old fashioned way will show the same ol 17-20 mpg that everybody gets. Mine shows i'm getting 24mpg right now. Yeah right. If I sound like an A-hole on this, it's cause i'm tired of every Ford/Dodge/Chevy owner telling me how great their mileage is on their chipped truck. They all get the same except the old 12 valve Dodge cummins, they did amazingly well.
  6. Rich Johns

    Rich Johns Platinum Level Contributor

    Thanks for your feedback MadMax:TU:
  7. Poppaluv

    Poppaluv I CALL WINNERS!!!

    I thought you diesel guys had to change the oil every 2k for the soot build-up? :confused:
  8. Rich Johns

    Rich Johns Platinum Level Contributor

    Wow, Diesel guy, never been called that before:idea2:

Share This Page