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2018GMC

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Posts posted by 2018GMC

  1.  

     

    On 1/19/2023 at 8:08 AM, Alex Olsen said:

    I have a 2014 Sierra slt z71 with the stock rancheros. 
     

    right now I have a 2 inch level spacer and the ride height  looks perfect. However it rides pretty bad. I’m assuming it’s a lot to do with my stock shocks being at 100k but whenever I am off-road and I hit many consecutive small bumps my front end starts to bounce uncontrollably. Feels like the front end bottoms out and wheels leave the ground. Not sure if I need more travel or just better shocks. 


    sounds like the 5100s are the way to go. If I wanted best ride possible should I ditch the spacer and max the 5100s lift.

    have the 5100 stock height with spacer. Or even somewhere in the middle and have like a 1 inch spacer on a middle lift setting on shocks. Not sure if this is a travel issue or a shock issue so would like some input on this. 

    I run the 5100's at max height and gained 2.25" of front lift. Do not run a spacer with the 5100's. Rides firmer than stock but still comfortable and very controlled.

    Your frontend is bouncing uncontrollably because you have no down travel. AKA when the wheels need to travel down after the suspension is compressed, they can't because you have the frontend maxed at maximum expansion.

    • Like 1
  2. I used to get service stabilitrak on startup every few months. I don't offroad much but our highways around here are rough enough to qualify. Never gotten the message driving. Have you checked for any codes and checked all your grounds?

     

    G218 ground shouldn't be an issue on a 2018. I would occasionally get service stabillitrack on startup but thats it. Check and clean all your grounds, especially the engine ground to body.
    There are 3 frame grounds:
    1. under driver seat on frame 
    2. behind front passenger wheel well
    3. on top of spare tire by trailer tow package.

    Your negative battery cable may have high resistance and need replaced. Dealer replaced mine and it didn't really change anything but they said it was out of spec for resistance.
     

    Here is the official Technical Service Bulletin TSB 
    https://static.nhtsa.gov/odi/tsbs/2019/MC-10168185-9999.pdf

  3. Anyone know If I can plug these into my factory radio and get the functionality or is there some interface module thats needed?

    I have a 2018 GMC sierra with max tow package that came with the large towing mirrors

    Echomaster mirror cameras
    2015-2019 GM Silverado/Sierra Factory matched mirror caps blind spot cameras ! | eBay

    Echomaster Front camera
    https://www.ebay.com/itm/134161439353

  4. I considered upgrading to the GM Big brake kit offered on K2xx trucks. I recall you can run 18” wheels from T1XX truck /suv or a 20” wheel from K2xx truck. GM still puts a 17” steel spare tire on vehicles with big brakes from factory so if you get a flat on the front you need to move a wheel from the rear to front then put the 17” spare on the rear because it won’t clear the front big rotor / caliper. 
     

    Stock wheels on t1xx trucks have different offset to clear the larger calipers. 

  5. 6.2 L92 VS 6.2 L9H. 
    L92 2007-2008

    L9H 2009-2013

    https://help.summitracing.com/app/answers/detail/a_id/4851/~/intro-to-the-l92%2C-l9h%2C-and-l94

     

    Isn’t the L92 rated lower hp and torque vs the L9H? Thought the L92 was 380hp and L9H was 403hp. Main differences were cam and vvt phaser. L9H was flex fuel compatible. L92 not. 

     

    I’ve been looking for a 2009 Tahoe 4x4 with the 6.2 L9H but they are kinda rare since 6.2 was only offered that one year in Tahoe LTZ trim only. This one year config also came with larger rear axle and 6-speed auto. 


    http://www.automobilegt.com/Brochures/Chevrolet/2009_Chevrolet_Tahoe.pdf

     

    GMT900  Suburban never got the 6.2. Of course 2007-2013 Yukon and Yukon XL Denali and Escalade came standard with the 6.2 but they were AWD, no selectable 2wd, auto 4hi, 4lo transfer case. 
     

    Odd the brochure lists 6.0 available in half ton suburban. Don’t think it ever was except in the hybrid versions and the 2500. 
     

    These are getting cheap-ish as the years and miles pile on…

     

    What years had valve spring failures or is it any year 6.2?

  6. If there was a dealership that had a service department that’s worth a $hit near me, I’d do the TSB but I’ve been to both the GMC and Chevrolet dealer and they both suck. Several hours for a oil change, they don’t call when it’s done. One of the dealers smashed my Evap canister using it as a jack point. Didn’t find out about that until weeks later when I got a check engine Evap small leak. Of course both denied responsibility.

     

    So here I am doing it myself 🙂

     

    The filter will get changed when I do the work and the pan cleaned since the dealer just hooks up the flush machine and then they’re done. 

  7. 21 hours ago, newdude said:

     

     

    Get the right stuff.  Do NOT use the multi-vehicle which when clearly looking at the compatibility chart for it covers Dexron 2, 3 and 6 only, NOT HP.  


    Only other compatible fluid I can find is Amsoil Signature Fuel Efficient ATF which is the most expensive at $18.69 per qt, $14.39 per qt if you buy the gallon and you are preferred customer. https://www.amsoil.com/p/signature-series-fuel-efficient-synthetic-automatic-transmission-fluid-atl/?code=ATLPK-EA

    Looks like I'll prob be going with Mobil 1 LV Blue label 124715 for &7.36 per quart when you buy the 6 pack

  8. Looks like the Mobil 1 LV Blue label 124715 is $46 for a 6 pack on the jungle website. They have a pic of the old black label but several reviews say it is actually the Blue label 124715
    Amazon.com: Mobil 1 Full Synthetic LV Automatic Transmission Fluid HP, 6-Pack of 1 quarts : Automotive

    What about using Valvoline Multi-vehicle 773775?
    Valvoline MaxLife Multi-Vehicle Full Synthetic Automatic Transmission Fluid (ATF) 1 GA - Walmart.com

  9. I'm thinking of doing a DIY at home flush on my 2018 6.2 with 8l90. Only has 20k on it and shifts great but have heard that the OEM fluid is hydroscopic and slowly absorbs water over time which causes shudder and shifting issues.

    I'm betting I need 12 quarts to do the flush at home, possibly more if I want to change transfer case atf as well which holds 3 pints.

    Looks like I could do this at home DIY flush in the driveway by:
    1. Drop pan, remove old fluid and clean pan, replace filter.
    2. Install pan and add 4 quarts of fluid.
    3. Remove the cooler block, inserting some poly line in the cooler port on side of transmission towards front of vehicle.
    4. Fill transmission with 4 quarts of new fluid.
    5. Run engine for 45 - 30 seconds to flush torque converter. Repeat until fluid is clean coming out of poly line.
    6. Blow cooler lines out with compressed air
    7. Replace cooler lines onto side of transmission.
    8. Fill with new fluid and check level.
     

    8L90 flushing proceedure.pdf 8 Speed Fluid Level Check.pdf 8 Speed Fluid Fill Procedure.pdf 8 Speed Fluid Change.pdf

  10. On 10/6/2022 at 6:20 PM, Miguel Olea said:

    Update!  I've only driven the truck 5K miles since I had the service done.  My buddy and I dropped the pan changed the filter and did a flush with 20 quarts of the new blue label Mobil 1 fluid.  I also added 1 10oz bottle of the lubegard platinum to further protect against any shudder although I've never had that problem.  The truck drives and shifts so much better which leads me to believe that GM had THE WRONG fluid in that flush machine.  It probably had Dexron 6.


    I'm thinking of doing a DIY at home flush on my 2018 6.2 with 8l90. Only has 20k on it and shifts great but have heard that the OEM fluid is hydroscopic and slowly absorbs water over time which causes shudder and shifting issues.

    Looks like the Mobil 1 LV Blue label 124715 is $45 for a 6 pack on the jungle website.
    I'm betting I need 12 quarts to do the flush at home, possibly more if i want to change transfer case atf as well which holds 3 pints.

    After how many quarts did you notice the fluid coming out of the return line get cleaner?

    Looks like I could do this at home DIY flush in the driveway by:
    1. Drop pan, remove old fluid and clean pan, replace filter.
    2. Install pan and add 4 quarts of fluid.
    3. Remove the cooler block, inserting some poly line in the cooler port on side of transmission towards front of vehicle.
    4. Fill transmission with 4 quarts of new fluid.
    5. Run engine for 45 - 30 seconds to flush torque converter. Repeat until fluid is clean coming out of poly line.
    6. Blow cooler lines out with compressed air
    7. Replace cooler lines onto side of transmission.
    8. Fill with new fluid and check level.

  11. On 5/31/2022 at 12:51 PM, Gangly said:

    Attached in PDF format is how they flush the fluid.  A simple drain and refill is a different procedure.

     

    8L90 flushing proceedure.pdf 779.03 kB · 28 downloads


    Looks like I could do this at home DIY flush in the driveway by:
    1. Drop pan, remove old fluid and clean pan, replace filter.
    2. Install pan and add 4 quarts of fluid.
    3. Remove the cooler block, inserting some poly line in the cooler port on side of transmission towards front of vehicle.
    4. Fill transmission with 4 quarts of new fluid.
    5. Run engine for 45 - 30 seconds to flush torque converter. Repeat until fluid is clean coming out of poly line.
    6. Blow cooler lines out with compressed air
    7. Replace cooler lines onto side of transmission.
    8. Fill with new fluid and check level.
     

    • Like 1
  12. 21 hours ago, Sal2018 z71 said:

    Hello did you ever figure it out? I’m having the same issues on my 2018 Silverado 1500

    G218 ground shouldn't be an issue on a 2018. I would occasionally get service stabillitrack on startup but thats it. Check and clean all your grounds, especially the engine ground to body.
    There are 3 frame grounds:
    1. under driver seat on frame 
    2. behind front passenger wheel well
    3. on top of spare tire by trailer tow package.

    Your negative battery cable may have high resistance and need replaced. Dealer replaced mine and it didn't really change anything but they said it was out of spec for resistance.

    Here is the official Technical Service Bulletin TSB
    18-NA-161 1..7 (nhtsa.gov)

  13. My 2018 6.2L L86 just rolled over 20k miles. I change oil every year and usually only put 4 - 5k miles on in that time. I've been running mobil 1 Full Syn and Pennzoil platinum. Recently joined the Amsoil club and will probably run the OE oil since I am changing with low mileage intervals. Not sure if the XL would benefit me much unless I start putting on more miles between changes.

    Walmart online has a 2pk of Mobil 1 212a filters for $18 which seems pretty good. I have run the Fram Ultra XG10575 after the mobil 1 m212a and oil looks the same at 4500 miles. Rockauto has cheapest price on fram before shipping but they limit order to 1 which kills the low price.

    Here's a youtube video comparison of m1-212a vs Fram XG10575. 

     

  14. 23 hours ago, Chadious80 said:

    There is only two sub wires from the Bose system right? Did you put a jumper wire on the input to the LC2I then run a pair of RCAs to the amp? I can’t find a definitive answer online anywhere. 
    Thanks


    Yes. I used the two wires from the Bose sub plug as the speaker level inputs on the lc2i. That’s the thick black speaker wire I ran from Bose sub plug into LC2i left speaker input. Since there was only one speaker level input from sub I ran it to the left input on the LC2i then just used some short wire to jump the left to right input on lc2i. Not sure if that even mattered. My JL XD300/1v2 turns on when it senses audio from the rca input so no remote wire needed. 

    3B843335-7A93-4056-9740-0C16CB986345.jpeg

    3F8DF5D3-81E9-4F8D-8CBA-E722E373F593.jpeg

    404C8160-1D9A-46CD-9C5C-6BCB20C2E076.jpeg

  15. On 8/10/2022 at 8:12 PM, Chadious80 said:

    I have that same Stealthbox and amp on order now for my truck. Where did you mount the amp? Is the audio control LC2I required? I want to get it done right the first time and not have to redo a bunch of stuff

    I used the LC2I and one of the wires off the factory Bose subwoofer plug for the amp power signal. Still rocking my JL stealthbox in center console. Has been good except had to reseal stealthbox box where woofer mates to box there was an air leak. 
    I mounted amp an lc2i under the rear seat. Ran all the wires along the passenger side under door sill covers. 

     

  16. Hi all,

     Anyone else have a small oil weep on front of engine above crank pulley? I think it’s the VVT cam phaser. I removed my air box and tube. Noticed a small oil weep. It just surrounds the sensor but not running down timing chain cover. Cleaned it off with carb cleaner. 
     

    My 2018 6.2L just turned 20k miles. I’m out of bumper to bumper but still have a few months of power train left. My dealer sucks so if it continues to weep may try replacing gasket myself? Has anyone done this? 
     

    Any other known leak areas on this generation of engines?

    C929490A-407A-4B2C-B66E-1B0709A47F2F.jpeg

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