GM Stuffs Hydra-Matic 8L90 With Technology

2015-Chevrolet-SilveradoHighCtry-017 (1) II

Last month GM officially announced it would offer an eight-speed transmission with the 6.2-liter EcoTec3 V-8 engine on the 2015 Chevrolet Silverado 1500, GMC Sierra 1500 and several full-size SUVs. Now GM has provided more details about the transmission, and it looks impressive — although we haven't driven it yet.

Gear ratios are 4.56:1 (1st), 2.97:1 (2nd), 2.08:1 (3rd), 1.69:1 (4th), 1.27:1 (5th), 1.00:1 (6th), 0.85:1 (7th), 0.65:1 (8th) and 3.82:1 (Reverse). This gives the new GM transmission more than a 7.0:1 gear ratio spread, which keeps all the ratios relatively close so the engine can stay close to the strongest part of the torque curve longer than a six-speed transmission does.

The eight-speed and 6.2-liter V-8 will have a maximum towing capacity of 12,000 pounds and will come standard with 3.73:1 axle gears. The transmission itself is no larger than the previous 6L80 transmission, but it does have a one-piece case and integrated bell housing for increased stiffness; additionally, the new transmission uses synthetic fluid for reduced friction and better heat dissipation. Speed sensors and software improvements were necessary as well to take advantage of the faster and smoother shift potential.

To read the full press release,  click here.

Manufacturer image

2015-GM-AutoTrans-8L90-019 II



This transmission is the only reason I am still considering buying a GM truck instead of a 2015 f-150. But I'm worried they rushed the launch just to draw attention away from the new ford. Can anybody say reliably whether this launched was actually planned for this time. Usually there is a lot of rumors and buildup to a launch like this, but it sure seemed like it kind of came out of the blue.

3.73? Where in GM releases does it say that?
GM should simplify things: 6.2 V8 + 8L90 + transfer case [no 4x2 configuration] + 3.08 ring/pinion.
That is it.
More than capable, in fact that would be the most capable 1500/half-ton pickup on the market for '15.

What???!!! GM is building their own transmission instead of buying it from another manufacturer like they've done with the Duramax transmissions? My experience with the GM transmissions is not good, like the old TM200 in my 1979 Pontiac Grand Prix and in my 2001 Buick Regal Limited. I was told I killed the transmission by towing a small travel trailer maybe a thousand miles total and the transmission was not built to handle more than just the car and passengers. I'll hold off until this new transmission has a couple of years in the real world and then make my buy GM or not decision. I'm not ready to trade right now anyhow.

So if all 6.2s come with an 8 speed and are rated up to 12,000 pounds pulling for 2015, then what the 2014s with 6 speeds REALLY HONESTLY be 2807 rated to pull? They would have lost capacity just like the 5.3s, lol!

Lol, we won't find out! Maybe GM found the 6 speed limitation and it wasn't much more better then the 5.3 with a 6 speed! But they don't want to say that, oh no!

Hope the 8 speed GM buyers enjoy having to get a premium trim to get only the 6.2 (no 5.3 or 4.3 option), and added expense of premium gas.

Apparently the 8 speed may not have a very long production life and was just installed to compete with the 2015 F-150. From AutoMotive News 2 days ago....

"Though the transmission is just now starting production, it may not have a long production life. A new 10-speed automatic transmission, under development in a joint venture with Ford, is due out in about 18 months. It’s unclear if the 8-speed will remain in production once the 10-speed arrives."

I'm sure an 8 speed tranny will do GM well. Anything that can help them get back in the game is good in my book.

The 8L90 had better outdo the 8 speed TorqueFlite performance wise, or it's going to mean a lot of wasted R&D $$$. GM needs to learn how to leap ahead of the competition, not just play catch-up.

The new 8,9 and 10 speed trannies we are starting to see definitely have a lot of potential. I think the biggest factor in how successful they are is how well it gets programmed.

There are just too many variables to make a tranny behave exactly the way a driver wants it to 100% of the time.

With Ram's 8 speed, I really haven't hear too many complaints in regards to how it operates, especially in comparison to the old 5 and 6 speeds in replaced in various Chrysler vehicles.

I am prone to think that automakers are on the right track with the new slushboxes coming to the market. What they need to realize is how consumers receive it is just as important as how well it performs and helps improve MPGS.

I hope this one is better than the 6L80e--that thing defines "slush box" in my wife's vehicle. The warranty is up next month and a programmer is going in to (hopefully) fix the lazy shifting.

I guess it makes sense to offer this transmission with the trim and engine that almost nobody is buying. That way if it doesn't work out then you've only pissed off a few idiots with too much money who are probably stupid enough to stay loyal.

To me it seems like GM has always been one of the most guilty offenders of the whole thing where they only offer a certain powertrain option with a narrow set of trim options.

I'm not even a GM customer and just that idea of it all frustrates me. I wouldn't be surprised at all if customers have moved over to other brands in order that they could get a larger variety of options.

Interesting Story on Yahoo "5 Car Brands Customers Don't Buy Twice"
This is about who has the LESS brand loyalty.

The 5 brands inspire the LEAST brand loyalty:

#5 Scion 25.79%
#4 Jaguar 25.45%
#3 Dodge 22.88%
#2 Chrysler 22.72%
#1 Mitsubishi 21.77%

I think the ratio is 3.42, not 3.73. Tom Wilkinson from Chevy posted on a story a few months back here on PUTC and said the 8-speed ratio was 3.42 with the NHT package for the 2015's.

GM always did a reputation for bad transmissions

Congratulations to GM to follow the RAM with 8 speed trany.
I mean it.

"GM always did a reputation for bad transmissions"

Are you kidding me?? That award goes to Dodge always has

Why would they invest in something like a transmission to only drop it? That Makes no sense. Gm Isn't putting10 speed transmission in anything till Ford puts an eight speed in there's and beats Gm. Even then the 10speed will be a premium option for only people who are willing to pay the large price for it. Having 3 transmission options sounds like a good way to diversify your lineups better and give the escalade its own tranny for a year or 2.

GM most likely would of had this plan in the works when they developed the transmission I doubt much extra R&D went into this because this transmission is in the Corvette. All they would have to do is test to see if it would hold up to 12K trailer loads. Extra cooling would cover that easily.

It seems the manufacturers are attempting to make strides in engine/drivetrain efficiencies prior to other easier and cheaper efficiency gains, like aero, weight reduction, etc.

We do know of the up and coming aluminium trucks from Ford and GM.

Fiat/Ram have done some marginal aero work with significant engine drivetrain work.

I do think the manfacturers will rely more on engine/drivetrain development over weight and aerodynamics for FE improvements.

The cost of developing engine/drivetrain changes vs aerodynamics is larger. I wonder why they have taken the harder path first?

This 6.2L V8 with 8 speed will be an awesome combination. It will be a good performer.


Ram, for instance, which has posted impressive sales figures in recent years and is the leader in customer loyalty.

Read more: 9 Cars Most Likely to Be Dumped - 24/7 Wall St.
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Ram the leader in customer loyality. ;-)

GM, number one once again in new technology! Try and catch up Ford and Ram but I know you will only fall behind even more.

@greg, News flash! Ram has had an 8 speed before G.M. So looks like G.M. is just catching up.

I like Boyz :P

This tranny will most likely go across the line up. Offer it on the rare less bought cars/trucks first to find and fix any problems if there is any. While that's going on they will be building up supply to offer it on the 5.3L and 4.3L. Then the 10 speed will come along. Question is will they keep the 8speed as a lower cost tranny option no one knows, but the 8 speed will be like when the 6 speed replace the 4 speed. The 6 speed was offer in top trims then worked its way across the line up.

There will be different torque levels that the 10 speed automatic will be produced at.
GM has the 8L90 for the supercharged Vette.
They also mention the regular Corvette has less internal clutch/brake elements (for higher efficiency)
So all GM needs is a medium-heavy duty 10 speed automatic that can work up to the 5.3 V8 torque/power levels.

Ford doesn't have an 8 speed automatic, so they need a 10 speed automatic that can work with the 3.5 ecoboost torque levels, higher than the GM 5.3 V8.

What is this silly obsession with that many gears?
I'm perfectly happy with the mpg on my 08 Silverados 4 speed
and plan on keeping it for another 10 years at least since its been perfectly reliable all this time..
I've been driving GM trucks for over 40 years and never had problems with tranny or engines in any of them,
so wouldnt ever consider any other brand
Heck my 67 Camaro had 2 speed Powerglide and it was perfectly adequate for my needs..

Is this or is this NOT the 8spd automatic Ford and GM were developing together?

I know such program was proposed and started (about a year and a half ago) and about nowish is when it should be entering production and I dont recall seeing anything saying they had ended the project.

@greg - lay off the bowtie flavoured coolaid.

You seem to forget that Ford and GM are co-developing transmissions.

That means they are working together on them.

There is NO lead or follow when you work together on shared transmissions.

As HemiV8 pointed out, FCA got there first with 8 and 9 speed transmissions.

GM really fell behind with the crash that heralded the start of the Great Recession. GM was looking at aluminum bodies a year before Ford.

I'm not usually a fan of white vehicles but that is a good looking truck.

Hemi V8
Yes! I agree with you that Ram leads in customer loyalty!
Ram is keeping Dodge and Chrysler in the lead the same way the F-150 is keeping Ford with its head above water.
But what numbers I would like to see is the percentage of repeat pickup buyers. I mean do more people trade in their old F-150 for a new F-150? Or do more Ford owners or Ram owners switch brands? I don't know?
I spent hours trying to find that data, I wonder if PUTC could find that cause it would make a very interesting story.
Consumer Reports used to have a survey "Would You Buy That Vehicle Again" but they don't have that anymore.
I judge a vehicle by looking at a large amount of them flooding the used market, when you see many of the same vehicles 2 or 3 years old for sale used I tend to think people don't like those vehicles that's why they trade them in, but the good vehicles its rare to see them for sale used cause people hold on to the vehicles they like best.
Recently I have noticed a lot of 2011-2014 F-150's flooding the used market (not rental vehicles)
People don't get rid of a newer late model pickup truck without a good reason, it could be they are disappointed with the horrible gas mileage instead of hating the truck.
I see the similar thing in motorcycles, just like used HD's are flooding the used market cause people don't like them, but the rare bikes you can't find for sale used are the Honda Interceptor and the Suzuki V Strom 1000 cause these are the good motorcycles that people love and keep forever.

I strongly believe Ford really screwed up by lying about the gas mileage the F-150 EB.
The worst thing they could do is lie to their customers.
This will ruin it for the 2015 F-150 cause nobody will believe the MPG numbers.
It looks bad, very bad that the Chevy and Ram V8's are getting better MPG numbers than the F-150 EB.
F-150 owners are tired of the blame and excuses Ford makes about WHY they are getting bad MPG numbers by blaming certain brands of gasoline and customers driving habits. If a service manager told me I was getting bad gas mileage cause I use a certain brand of gasoline I would climb down this throat and rip his guts out!
The 2015 F-150 will be a flop cause nobody will believe Ford that it gets better gas mileage!

@Hemi Monster

"I'm sure an 8 speed tranny will do GM well. Anything that can help them get back in the game is good in my book."

You do know GM sells the most 1/2 tons right and then Ford followed by Ram. The gains Ram made on GM seem to be in the HD market where they have a sourced Cummins and Aisin tranny. Your measuring success based off what you like and not how many units sold. As for GM's 8-speed needing to be better your taking a lot of credit for a ZF tranny that was sourced to Chrysler and not designed by them.

@ TRX-4 Tom

The smaller 5.3L with 2 less gears tows and hauls more than the larger 5.7L Hemi with 2 more gears and you take shots at the 5.3L. I agree with you and Hemi Monster on the 6.2L only being available in high priced trims that go into the 6.0L HD range.

As far as gear ratios go I think I still like Rams the best.

My question is GM where is the start-stop I hope it will come on the 16's. Finish the job GM.

Yes Ram had an 8 speed first, but they need it more with the worst selling half ton, and they bought theirs from ZF and just tweaked it a little. Their version did not go through all the validation testing GM has put their through or that the 10 speed will go through. GM started to cut back on this in the 80′s and they had failures. Now they are back to the testing they used to do and we will not have failure like in the past.

Note Ram has had recalls and failures with their ZF box.

Top (8th) gear at 0.63 still lower than Top/6th gear in Tundra at 0.59.

Yes I know the Tundra has 4.1 and 4.3 rear differential vs this 3.73 but do the math and it isn't that different on the highway. The Chevy needs the extra low 1 and 2 granny gearing to get out of the hole with a load. Seems to me that this tranny is more about maintaining good tow rating numbers than adding FE.

Think about time spent in top gear with torque converter locked up on a full size truck with some load in or behind it - how much higher can this gear be and still be used enough to improve mileage. Maybe those in flat lands will get their money's worth, but in the hilly parts, my bet is higher top gears will only get used under light throttle down hills where the lower gearing isn't guzzling anyway.

A spread of 7 is nice, I just don't think that many gears are needed to accomplish it when paired with an engine with good power.

I will add that coming from a 4 speed to a 6 speed now, I find there is a lot more hunting and shifting going on that I am still getting used to and hear more now since adding CAI and dual exhaust.

This also reminds me of years ago when Chevy redesigned the Corvette and it's fuel mileage went down and they added programming to shift from 1st to 4th to help EPA numbers and avoid the gas guzzler tax.

@Tom#3 - Read HemiV8's link. Loyalty clearly identifies which brands will see repeat customers.

"The car makes with the most loyal customers also tend to have strong sales. Ford (NYSE: F), Honda (NYSE: HMC), and Toyota (NYSE: TM) — brands that keep at least 50% of their customers coming back on average — are also among the best selling brands in the United States."

is that tow capacity with the bumper and everything else removed as they got caught doing before? Love those tow numbers, hahaha

This transmission option for the Silverado 1500 is much like the L86 6.2L V8 option.....they exist for the purpose of keeping the price low on Corvette cars.

Let me know when the boys at GM start caring about anything else other than the sports car.

Meanwhile, I'll keep chugging along with the ol' Big Six while only having one true option for a modern pickup with real truck engine: Cummins!

"Yes Ram had an 8 speed first, but they need it more with the worst selling half ton."

Posted by: Gregory Stevens | Aug 24, 2014 8:57:28 AM


Doesn't Ram sale more than G.M.C. 1/2 ton?

Doesn't Ram sale more than toyota 1/2 ton?

Doesn't Ram sale more than nissan 1/2 ton?

Vehicle 1H 2014 1H 2013 Change

Ford F-Series 365,825 367,486 (0.5%)
Chevrolet Silverado 240,679 242,586 (0.8%)
Ram Pickup 203,860 170,319 19.7%

To date, the Silverado has sold approximately 240,000 units, and it wouldn't be surprising to see Ram become the second best selling pickup in the U.S.

While I don't think it's likely that Ram will surpass the Silverado in sales in 2014, I certainly think it's plausible in 2015 -- which would happen if sales growth remains the same for each vehicle.

P.S. G.M. is on a record Recall year.

@HEMI V8 - unless Ram adds a night shift they can't make much more than 300K per year.

The rear axle ratio in the L86, 8L90 Silverado LTZ Max Tow is 3.42.

The 5.7 uses a 3.73 to compensate for less displacement and the 6 speeds higher first gear starting ratio.

GM seems to have rushed their 8 speed 8L90 into production before doing a good R&D. Lots of blogs about the 8L90 transmission problems.
My 2015 Escalade has been reprogrammed 3 times and still has problems. #PIP5337 shake or shudder on acceleration excessive engine RPM fluctuation. Plus down shift hang up. Apparently they are now rushing to redesign it. $73,000 and 8k miles and the transmission is junk? Maybe I should have them buy it back.

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