looking to buy 14 (6.2/6sp) or 15 (6.2/8sp)

TheGovernment · June 22, 2017

I also work at a gm dealership and we've done maybe 15 since the 8 speed has been introduced.

The issue is there for some for sure but people read these forums then get absolutely convinced they have the issue.... Just like the Chevy shake. My God lol

We all know the 8 speeds can be kinda weird sometimes. They have funny shifts etc.

I drive my 17 like I stole it, not one issue so far.

Chets LS3 · June 22, 2017

Thanks for the replies and advice guys/gals.

keep them coming with any positive/negative input.

I found a 6.2/8sp somewhat close to me and I'm going to drive it as soon as this pansy Tropical storm stops dumping rain.

btw the 6.2/6sp i drove rode veryyyy well on the interstate, I "think" i felt a really small vibration at 82-84 mph. but its 18x better than my 05 chevy or my 2012 tahoe (police unit) and my 16 C7. so the ride on the 14 denali i drove was VERY nice for a pickup IMO.

powerhaulic · June 22, 2017

If that isn't an over exaggeration I don't know what is. 4.03 and 3.42 vs 4.56 and 3.23 with a slightly tighter spread does not equal "blows it away". It will "blow away" a NA V6 or other smaller less powered trucks but the same motor with a slight gear change is not that big of a difference. Helps yes but big difference, not at all...

Tyler

Not at all...........

As is posted above, towing there is no comparison.

We tow a 9000# travel trailer, the 8spd works perfect in the mountains.

Chets LS3 · June 22, 2017

I agree on the forum lemmings [emoji23][emoji23]

Personally I have corrected at least 30 vehicles with the shudder problem in just my dealership. I work on the transmissions. These 30 vehicles would include the Escalade, Silverado, Camaro and Corvette.

This being a isolated problem to a limited few? I don't think so. I'm curious to see how it'll be when some get some real miles on them. Why do you think GM worked on lowering that power train warranty? It saves them money. GM introduced software into the ECM's of many vehicles beginning in 2013 called "Torque Management" . That's why our throttle response sucks as well. It's made to open the throttle slowly so the drivetrain doesn't take harsh abuse from constant wide open throttle or moderate throttle. They are so confident in this that the software was the beginnings of warranty adjustments.

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Chets LS3 · June 22, 2017

I also work at a gm dealership and we've done maybe 15 since the 8 speed has been introduced.

The issue is there for some for sure but people read these forums then get absolutely convinced they have the issue.... Just like the Chevy shake. My God lol

We all know the 8 speeds can be kinda weird sometimes. They have funny shifts etc.

I drive my 17 like I stole it, not one issue so far.

What are the fixes/results?

TheGovernment · June 22, 2017

Mostly torque converters. For the most part, a quick relearn and driving aggressively when it's learning seems be enough. Im a painter but the manager and trans tech are my boys lol

The main issues is, people have this weird thing that is the trans does anything abnormal, it's defective and needs to be replaced. One weird clunk from a downshift or anything and they are arguing for a replacement.

I thank God I don't have to deal with people that come though the doors.

I have respect for anyone that can deal with customers without telling them to for fuc$ themselves. They think everything sould be free no matter what.

We had a guy last week poor oil into his rad somehow, then blame the tech for doing it but the tech was wearing a head cam and recorded from the moment he opened the hood and he guy told him he edited the video hahaha. Urgh.

Z45 · June 22, 2017

They do, along with a few more heavy duty towing options. Good call on the Denali, good looking trucks.

No they don't. Max towing is not available on a Denali which has a complete different suspension. In 2015 its Magnetic Ride. No big mirros available on the Denali either, you will have to install them at much expense. I checked into it, GM mirrors are about $700 + wire harness & installation (program BCM).

My brother got a 2017 GMC SLT 6.2L w/Max Towing. Wanted a Denali but Max Towing is NOT available on the Denali, competing suspension systems. If you are towing, get a 6.2L with the NHT Max Trailering option, not the Denali.

Max Towing (rpo NHT) gives you bigger rear axle, heavier rear springs, lower gear ratio, bigger towing mirrors and better cooling.

powerhaulic · June 22, 2017

No they don't. Max towing is not available on a Denali which has a complete different suspension. In 2015 its Magnetic Ride. No big mirros available on the Denali either, you will have to install them at much expense. I checked into it, GM mirrors are about $700 + wire harness & installation (program BCM).

My brother got a 2017 GMC SLT 6.2L w/Max Towing. Wanted a Denali but Max Towing is NOT available on the Denali, competing suspension systems. If you are towing, get a 6.2L with the NHT Max Trailering option, not the Denali.

Max Towing (rpo NHT) gives you bigger rear axle, heavier rear springs, lower gear ratio, bigger towing mirrors and better cooling.

Hey, thats my truck.............lol

You actually get the larger ring gear with all 6.2's but cant get the lower ratio without NHT

Z45 · June 22, 2017

The 6.2L ring gear is same as 5.3L, 9.5 inch 2014 up and prior to that the 8.6 inch.

The only way to get a bigger ring gear (+ 1/4 inch) is with the Max Trailering option which comes with the 9.76 inch (2014+) while all the rest of the V8 models come with 9.5 inch including 6.2L. 2013 back is was the 9.5" with NHT and 8.6 in all without NHT. 6.2L did not get a bigger rear axle, had a 2012 Denali and it did not.

The engine has no bearing on rear axle size.

michigan2500hd · June 22, 2017

The 6.2L ring gear is same as 5.3L, 9.5 inch 2014 up and prior to that the 8.6 inch.

The only way to get a bigger ring gear (+ 1/4 inch) is with the Max Trailering option which comes with the 9.76 inch (2014+) while all the rest of the V8 models come with 9.5 inch including 6.2L. 2013 back is was the 9.5" with NHT and 8.6 in all without NHT. 6.2L did not get a bigger rear axle, had a 2012 Denali and it did not.

The engine has no bearing on rear axle size.

Not entirely true. I had a 2011 6.2 that came with a 9.5" rear. The reason your Denali 6.2 didn't have it is because it is AWD. From 2009-13 all 6.2's with selectable transfer cases came with the semi- floating 14 bolt ( 9.5") rear axle.

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Lgetz · June 22, 2017

Towed a trailer loaded with Scion TC for 350+ miles day before yesterday with 0 issues. Easily maintained 70+ mph and truck wasn't hunting for gears even when going through town. Not one instance where the revs went sky high either. 2015 All Terrain 6.2 with 8 speed and 3.23 gears.

MrNasty · June 22, 2017

I have a 2015 6.2 8 speed. I never had the shudder but I did get the torque converter replaced because rpm's were fluctuating at steady speed, plus stator assembly for delayed engagement into drive. I just recently had software update to the TCM and transmision is much smoother and very improved. I can say that before the update on my transmission , I did wish mine had the 6 speed because the one in my wife's truck is very smooth. Now Im liking the 8 speed even more and its also better in tow mode than before the update. I tow with it quite a bit and my ranch is in the hillcountry so I have to climb and descend quite a bit and it handles pretty good. The only 6 speed I have to compare to is my wife's 5.3, so cant say if the 8 or 6 speed is better behind the 6.2. Just giving my experience with my truck.

JimCost2014 · June 22, 2017

No they don't. Max towing is not available on a Denali which has a complete different suspension. In 2015 its Magnetic Ride. No big mirros available on the Denali either, you will have to install them at much expense. I checked into it, GM mirrors are about $700 + wire harness & installation (program BCM).

My brother got a 2017 GMC SLT 6.2L w/Max Towing. Wanted a Denali but Max Towing is NOT available on the Denali, competing suspension systems. If you are towing, get a 6.2L with the NHT Max Trailering option, not the Denali.

Max Towing (rpo NHT) gives you bigger rear axle, heavier rear springs, lower gear ratio, bigger towing mirrors and better cooling.

Was not referring to the Denali's, was responding to the question about the max tow package mirrors. Then complimented his choice if he chooses to buy a Denali, which you are correct, does not have a max tow package.

Chets LS3 · June 22, 2017

To find a used max tow 6.2 would probably be insanely hard!!

Don't the 15+ denalis have mag shocks? 14s do not?

michigan2500hd · June 22, 2017

I stumbled across the used 15 I bought. Funny thing was that I was looking at a new one but couldn't do a new payment. Got online and mine was the first truck that popped up. You might get lucky and find a used one.

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