2020 Transmission & Suspension vs. 2019

hotrodz37 · November 18, 2019

Hey All,

I am looking at pulling the trigger on a new truck relatively soon. I am curious how much better the suspension tuning and 10 speed transmission are vs the 2019 8 speed and suspension. I know the only real answer is to get out and drive both which I plan to do soon. Both would be the 5.3L.

Are the 2019 8 speeds having the same issues as the previous years or are they fixed? Seems like from reading the 2019 got a new torque converter and has better programming.

There are some 2020 GMC Sierra SLT's that are popping up for around $11k off which is nice (I would have to drive about 3 hours to make that deal), but I can get a 2019 Denali for $12-$13k off right now at the local dealer. Rather have a Denali but if tranny and suspension updates are that big of a difference I will probably go for the 2020 SLT.

Thanks in advance for any insight!

Edited November 18, 2019 by hotrodz37

mcgee500 · November 18, 2019

Here too I'm hoping for some feed back on this. I'll be ordering a 2020 in a few month and want to know 8 or 10 speed. As of now I'm going with a loaded RST 6.2 10 speed. Waiting to here from some you you that already have one.

Donstar · November 18, 2019

I'd make the three hour drive. The fact that the truck is one year newer is worth the trip, imo.

newdude · November 18, 2019

8 speed has shudder potential up to a certain build date, I think April 2019? They were still assembling with the old fluid.

10 speed much better. Id go 2020.

Cpl_Punishment · November 18, 2019

From what I've read on here, the 10 speed is smoother than the 8 speed, even the 8 speed with the new fluid. The suspension was also retuned for 2020 to improve the ride.

Also, if MSRP on a 2019 Denali is more than $2k higher than a 2020 SLT, wouldn't you still come out ahead on the 2020?

FishinJ · November 18, 2019

I had a 2015 with the 8 speed and put 2 torque converters in (thankfully under warranty). With all the updates and the latest torque converter it ran fairly smooth but would have some small clunks every now and then. The 2020 with the 10 speed is soooooo smooth and would highly recommend it compared to the 8 speed. No idea about the suspension between the 2019 and 2020.

Thomcat · November 18, 2019

4 hours ago, newdude said:

8 speed has shudder potential up to a certain build date, I think April 2019? They were still assembling with the old fluid.

10 speed much better. Id go 2020.

Shudder potential seems related to the initial fill with Dextron fluid which is hydroscopic. Cutoff date for Dextron vs. new Mobil1 HP fill was 3/1/19. Can confirm new fluid by looking for RPO code MQE - TRANSMISSION, 8-SPEED AUTOMATIC. And I'm sure that even with a flush and refill with Mobil1 the results are only as good as the method and use of the special machinery designed for this purpose.

The 2019+ 8 speeds have a significant redesign function from the previous years - necessitated by the addition of the start- stop system. Operation of the tyranny is the same regardless if the defeat button is engaged or not. Operation of any automatic requires that the transmission pump must maintain pressure on the bands that engage the planetary gear drums which shift the transmission....loss of pressure will release the band(s) and the drums and the gears will not engage until pressure is restored. No problem in a regular engine situation where it is always turning powering the tranny pump or in a cold start takes a second or two to run up the engine and shift into gear where a loss in pressure will not be noticed.But with an autostop engine when the engine stops, no tranny fluid pump pressure, bands release and no drive until pressure is restored. And when the engine restarts for the second or two until the tranny pump again provides sufficient pressure, the vehicle will hesitate and then bang into gear like it was kicked by a mule.

The 2019+ trannys are redesigned to prevent this during an autostop cycle - the servos controlling the bands are not supplied directly by the tranny pump; instead they incorporate an "accumulator" something like the vacuum chamber on a power brake, But instead of storing vacuum it stores fluid pressure, charged by the tranny pump while the engine is spinning and used to maintain pressure on the band servos for the duration that the engine is in auto stop. ( I guess that another solution would be to use an electric tranny pump - but they don't). It is irrelevant whether s/s is active or defeated, fluid pressure for tranny operation is always provided directly by the accumulator and not by the tranny pump.

And here is my .02 theory why the s/s equipped tranny gives a hard 1-2 shift for the first few shifts after a long sit or overnight cold. On a long sit with the engine off the pressure in the accumulator will bleed down and the initial charging, when the engine starts, with cold tranny fluid to the unpressurized accumulator will affect pressure to the servo for an abrupt shift. Once the accumulator is uniformly charged with fluid after the first one two 1-2 shifts, it will resume a normal shift pressure. Anyway there definitely is an accumulator in the system for that purpose, just as in my Traverse 9 speed with s/s, the rest is my best guess, but that is the way that mine works and the theory seems to fit. Once my tranny temp gets to about 80F under normal acceleration smooth as silk with no noticeable shifts in any gear.

smrr1 · November 19, 2019

My 2019 6.2/10 speed is fantastic so i can comment on the transmission being worth going 2020. The suspension i got no clue on. I have not been in a 2020. I will say my 2019 AT4 is pretty good so if they made it even better i’d go 2020 if i were you.

Edited November 19, 2019 by smrr1

ShamrockShooter · November 19, 2019

I had a 2019 5.3 8 speed and it was absolutely awful. My 2020 5.3 with 10 speed is amazing after 1,000 miles, not one clunk or bad shift. I would pay $5000 more for this truck with the 10 speed. It is that much better. Maybe time will change my mind but so far it's a 10 out of 10 for the 10.

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cltsig · November 19, 2019

The 10 speed is excellent. Whatever you get I would go for a 10 speed.

hotrodz37 · November 19, 2019

Thanks for all the replies guys, really appreciate it! Question for you - what trim do you have to get to get the 10 speed. After looking around it looks like most of the 2020 SLT’s in my area have the 5.3 and 8 speed. Is the 10 speed an option assuming it doesn’t come standard?

Nevermind - answered my own question, in Denalis, AT4, and 4wd SLE and above. Problem is I only need RWD. Decisions decisions.

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bartonjude · November 19, 2019

I'd really like to know what was improved/changed on the suspension for 2020. Anyone care to "drill down" on that portion of the OP's question?

smrr1 · November 19, 2019

Maybe wait a little. I might be mistaken but i am pretty sure i remember seeing that 2020 would offer a 5.3/10 speed. Per the build your own its still just showing 6.2 with the 10 speed and that requires 4wd. Unless you go 3.0 diesel. Just weird. Let people have what they want!!

Cpl_Punishment · November 19, 2019

2 hours ago, hotrodz37 said:

Thanks for all the replies guys, really appreciate it! Question for you - what trim do you have to get to get the 10 speed. After looking around it looks like most of the 2020 SLT’s in my area have the 5.3 and 8 speed. Is the 10 speed an option assuming it doesn’t come standard?

Nevermind - answered my own question, in Denalis, AT4, and 4wd SLE and above. Problem is I only need RWD. Decisions decisions.

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From what I've read on here, I'd say the 10 speed is worth it but, given how much snow and ice we get here, I would never buy a rwd truck so I might be slightly biased.

Edited November 19, 2019 by Cpl_Punishment

Sierra Dan · November 19, 2019

1 hour ago, bartonjude said:

I'd really like to know what was improved/changed on the suspension for 2020. Anyone care to "drill down" on that portion of the OP's question?

Nothing really changed from 2019-2020 suspension wise on T1. Engine/Transmission combinations with the 10 speed. Yes.

Now from your K2, yes. Whole new frame and all. Reduced weight can also factor in to the Suspension feel.

However, Suspension is a loose term. You have to consider the package types in this. Such as Z71/X31 Vs 2wd, 4wd Max Tow etc.

The list goes on and on.

OP, I recommend you test drive several trim levels/suspension packages to see what fits your comfort level best.

Compared to your 2014 K2, A 19 or 20 T1 with similar setup may ride better or worse to you.

Same with the Transmission.

Although a 2020 model will give you more options with the 10 speed combo over a leftover '19 model this late in the year.

Good luck! :thumbs: