2018 ..6.2 AND 8 SPD..ISSUES or???

[ajensen383]

So I bought my 2018 Sierra 6.2L max tow in Feb and I Just turned 6000 miles....My previous truck was a 2011 Silverado 6.2, 6spd and 3.73 ( due to the max tow) ...Am I crazy since it seems that my old truck would run circles around this new one??

FIrst off.. I love the the truck as a whole, the  interior and the way this truck looks, is sooo much better than the GMT-900...My biggest complaint is this 6.2L feels like a 5.3 or even 4.3L compared to my L9H ...Is there something Im missing??...Even past the "click" its still not as fast as my 11 was ...

 

The other thing is this 8speed... Now I don't have any of the shuttering or clunking issues that others have topics about, but this trans sometimes feels like a CVT when at light throttle (cant even tell its shifting and it feels like the converter is slipping until I give it more gas, then it seems to "couple together" and go)....When its on the highway its fine, but driving around back roads , it gets kind of annoying as well , sometimes it upshifts fast other times it will upshift later , and yet other times it will go into v4 mode for a bit then upshift ..I thought V4 mode was only available in the higher gears?? It seems to me that it puts it in V4 at times somewhere in gears 3-5 as well...ITs a pretty frustrating transmission... The 6spd in the 2011 had nice firm upshift and you pretty much knew what gear you were in..

[Pearl2017]

How is your fuel mileage from old to new truck? Reason I ask is that the entire reason IMO that the trans is mushy and like a CVT is to squeeze every last drop of mileage from the vehicle to meet federal law. taller diff gear lower cruise RPMs and a TC/TCC that slips constantly while cruising is the strategy that gets them that. If you want to get more performance read some posts about CAI's and getting a tune. Performance can/will go up and mileage will go down.

[SSchup]

Like you I sold my 2013 GMC Sierra SLT 6.2 back in July and bought a 2018 Silverado LTZ with the 6.2 Max Tow. The 2013 didn't have the NHT package, so just the 3.42 axle ratio. I was actually impressed with the performance of the 2018 6.2 over the 2013. It's possible that is due to the 2013 having a 4" lift with 20x10 wheels and 295/55/20 Toyo MT's, a pretty heavy tire over the stock 275/55/20 Goodyear Eagle LS's.

 

I've also been pretty happy with the 8 spd and how it shifts, especially after reading of others problems with them. The V4 mode has been pretty seamless also. I just bought a Manaflow MF cat back exhaust so I plan to pick up the Range devise to just eliminate V4. Seems as though most people complain about the V4 sound on the after market exhaust.

[2018GMC]

Like you I sold my 2013 GMC Sierra SLT 6.2 back in July and bought a 2018 Silverado LTZ with the 6.2 Max Tow. The 2013 didn't have the NHT package, so just the 3.42 axle ratio. I was actually impressed with the performance of the 2018 6.2 over the 2013. It's possible that is due to the 2013 having a 4" lift with 20x10 wheels and 295/55/20 Toyo MT's, a pretty heavy tire over the stock 275/55/20 Goodyear Eagle LS's.
 
I've also been pretty happy with the 8 spd and how it shifts, especially after reading of others problems with them. The V4 mode has been pretty seamless also. I just bought a Manaflow MF cat back exhaust so I plan to pick up the Range devise to just eliminate V4. Seems as though most people complain about the V4 sound on the after market exhaust.

FYI range device is on clearance woot.com $78

[2018GMC]

19 hours ago, ajensen383 said:

So I bought my 2018 Sierra 6.2L max tow in Feb and I Just turned 6000 miles....My previous truck was a 2011 Silverado 6.2, 6spd and 3.73 ( due to the max tow) ...Am I crazy since it seems that my old truck would run circles around this new one??
FIrst off.. I love the the truck as a whole, the  interior and the way this truck looks, is sooo much better than the GMT-900...My biggest complaint is this 6.2L feels like a 5.3 or even 4.3L compared to my L9H ...Is there something Im missing??...Even past the "click" its still not as fast as my 11 was ...
 
The other thing is this 8speed... Now I don't have any of the shuttering or clunking issues that others have topics about, but this trans sometimes feels like a CVT when at light throttle (cant even tell its shifting and it feels like the converter is slipping until I give it more gas, then it seems to "couple together" and go)....When its on the highway its fine, but driving around back roads , it gets kind of annoying as well , sometimes it upshifts fast other times it will upshift later , and yet other times it will go into v4 mode for a bit then upshift ..I thought V4 mode was only available in the higher gears?? It seems to me that it puts it in V4 at times somewhere in gears 3-5 as well...ITs a pretty frustrating transmission... The 6spd in the 2011 had nice firm upshift and you pretty much knew what gear you were in..

 

I have an 2018 6.2 NHT with just under 5k miles. I completely agree with your description of the 8 speed and constant slipping during light throttle. I’ve read several posts that the L86 6.2 really comes alive after 10k miles. Supposedly it’s in a defined break in mode until then. As far as the 8 speed goes I hope we got good ones in 2018 that don’t need replacement or torque converters.

Remember starting 2016+ we have shorter powertrain warranty. 3yr 36k bumper to bumper and 5yr 60k powertrain. Starts the day you take delivery.

 

[SSchup]

9 hours ago, 2009GMC said:

 

FYI range device is on clearance woot.com $78

 

I sure couldn't find it.

[ajensen383]

15 hours ago, Pearl2017 said:

How is your fuel mileage from old to new truck? Reason I ask is that the entire reason IMO that the trans is mushy and like a CVT is to squeeze every last drop of mileage from the vehicle to meet federal law. taller diff gear lower cruise RPMs and a TC/TCC that slips constantly while cruising is the strategy that gets them that. If you want to get more performance read some posts about CAI's and getting a tune. Performance can/will go up and mileage will go down.

Actually my fuel mileage has been great with this truck compared to the old one...I can easily get 20-22 mpg on the highway mostly due to V4 mode,and my daily commute im getting high 17s-low 18....My 2011 was about 18mpg max highway and high15s -low 17s on my daily commute

[ajensen383]

11 hours ago, SSchup said:

Like you I sold my 2013 GMC Sierra SLT 6.2 back in July and bought a 2018 Silverado LTZ with the 6.2 Max Tow. The 2013 didn't have the NHT package, so just the 3.42 axle ratio. I was actually impressed with the performance of the 2018 6.2 over the 2013. It's possible that is due to the 2013 having a 4" lift with 20x10 wheels and 295/55/20 Toyo MT's, a pretty heavy tire over the stock 275/55/20 Goodyear Eagle LS's.

 

I've also been pretty happy with the 8 spd and how it shifts, especially after reading of others problems with them. The V4 mode has been pretty seamless also. I just bought a Manaflow MF cat back exhaust so I plan to pick up the Range devise to just eliminate V4. Seems as though most people complain about the V4 sound on the after market exhaust.

Yeah having the heavy wheels and tires definitely would kill some of the performance on your 2013. I did notice when I put my stock tires and wheels back on to sell my 2011 it felt like I gained another 50hp...

 

Im happy with the way my 8spd shifts , yes, it shifts early but it can pull it easily. I have no issues so far with any clunking or shuttering like many people have , it just doesn't feel hooked up as it should at light throttle, that's my biggest complain... I agree the V4 has been fairly seamless and I actually like the v4 mode, especially on the highway. I don't feel a need for it on my daily commute and it is constantly in and out of v4 and I don't feel it does a lot, but if im taking a highway trip, I think its definitely worthwhile for fuel mileage. I have a Corsa exhaust on mine and have no issues with it in V4, most of the time while cruising, I cant even hear it, Corsa does a super job of eliminating any drone..

[ajensen383]

9 hours ago, 2009GMC said:

 

 

I have an 2018 6.2 NHT with just under 5k miles. I completely agree with your description of the 8 speed and constant slipping during light throttle. I’ve read several posts that the L86 6.2 really comes alive after 10k miles. Supposedly it’s in a defined break in mode until then. As far as the 8 speed goes I hope we got good ones in 2018 that done need replacement or torque converters.

Remember starting 2016+ we have shorter powertrain warranty. 3yr 36k bumper to bumper and 5yr 60k powertrain. Starts the day you take delivery.

 

At least Im not alone thinking that my tranny feels like its always slipping at light throttle....Im hoping it gets better after 10k miles, its just a little disappointing to me right now, knowing what I had. I thought this truck would be night and day difference since it has more gear and torque than what I had.

 

I don't seem to have any of the other issues I read about on here with the tranny. No clunking or shuttering , just a strange disconnected feeling at light throttle

 

Im ok on the warrany, as I will be out of the 5year warranty faster than the mileage, I only put on about 10k a year. My 2011 had the 5/100 and I was at 7 years 72k miles when I got rid of it

[2018GMC]

1 hour ago, SSchup said:

I sure couldn't find it.

https://sellout.woot.com/offers/range-technology-active-fuel-management?ref=w_cnt_lnd_cat_tool_4_2

[Roscopcoletrain]

of course no Canada love lol

[Lgetz]

Ajensen try these 3 things and see if your throttle response, V4 issue, and laggy feel don't improve.   First you may need to perform the "paint stick fix" to your gas pedal.  Others have reported that this helped improved gas pedal feel and response.  2nd try running your truck in M7(7th gear max) around town.  This locks out both 8th gear and V4/AFM mode.  I run this way and only shift to 8th gear at 68+ mph on the highway.  Don't really notice any difference fuel mileage wise.  Lastly try disabling the grade braking on your truck.  Push the tow/haul button down for 7 seconds or so and once you release a message appears on the DIC screen saying it was disabled.   When letting off gas approaching a stop sign/light I notice my truck is not as laggy.  Never noticed this much until once my older brother was driving on one occasion.   He was turning left on a green light and accelerated to beat a car going opposite direction.  He let off gas mid turn and the truck seemed to literally stop.  Made things hairier than necessary.  

From reading on this forum I picked up on these techniques and feel it makes a noticeable difference.

[SSchup]

10 hours ago, 2009GMC said:

https://sellout.woot.com/offers/range-technology-active-fuel-management?ref=w_cnt_lnd_cat_tool_4_2

Guess I'm a little late, shows sold out.

[2018GMC]

On 9/25/2018 at 3:48 AM, ajensen383 said:

Yeah having the heavy wheels and tires definitely would kill some of the performance on your 2013. I did notice when I put my stock tires and wheels back on to sell my 2011 it felt like I gained another 50hp...

 

Im happy with the way my 8spd shifts , yes, it shifts early but it can pull it easily. I have no issues so far with any clunking or shuttering like many people have , it just doesn't feel hooked up as it should at light throttle, that's my biggest complain... I agree the V4 has been fairly seamless and I actually like the v4 mode, especially on the highway. I don't feel a need for it on my daily commute and it is constantly in and out of v4 and I don't feel it does a lot, but if im taking a highway trip, I think its definitely worthwhile for fuel mileage. I have a Corsa exhaust on mine and have no issues with it in V4, most of the time while cruising, I cant even hear it, Corsa does a super job of eliminating any drone..

Did you buy the GM corsa that has the flapper or directly from corsa with no flapper? Corsa only makes one exhaust for the 6.2 correct?

 

no power gains but 404% increased flow is advertised lol

 

https://www.corsaperformance.com/collections/2018-gmc-sierra-denali-1500-crew-cab-standard-bed-6-2l-v8/products/3-0-cat-back-14866

[ajensen383]

12 hours ago, 2009GMC said:

Did you buy the GM corsa that has the flapper or directly from corsa with no flapper? Corsa only makes one exhaust for the 6.2 correct?

 

no power gains but 404% increased flow is advertised lol

 

https://www.corsaperformance.com/collections/2018-gmc-sierra-denali-1500-crew-cab-standard-bed-6-2l-v8/products/3-0-cat-back-14866

No I didn't get the GM one... I was thinking about it, but it wasn't loud enough for me from the videos I heard online...

 

Corsa technically only makes 1 exhaust for the 6.2 but I didn't want a single side exit, I like dual rear exits, so I found a Corsa made system  that Lingenfelter used on their Reaper trucks...Lingenfelter had Corsa specially make the dual outlet systems for their trucks.

 

https://www.lingenfelter.com/product/CP24204.html#.W7dnPmf2aL8

 

Just an FYI Exhaust systems from a GMT-900 will work on K2's... I compared the above lingenfelter (made for 14-up trucks) to the Corsa I had on my 2011 ( that I removed before I sold it)  and they are EXACTLY the same pipes. I could have saved some cash If I knew that before hand.