[flyinglow]

I thought the GM rep said the trailboss would have lockers a couple years ago? I think it was a TFL video with the female product manager or something.

It was the chief Silverado EV engineer Michelle Kraatz. Things change. Back then the ZR2 and AT4X were separate trim levels in the ICE range. Then they made them option on the Trail Boss/AT4.

I don't imagine the lockers add too much to the cost other than being relatively low volume. The DSSV shocks, however, as factory aftermarket kits for ICE trucks cost over $3k.

We are going to have to wait for reveals but the order guide has nothing on lockers or shock absorbers.

 

[flyinglow]

Lockers, it'll have to have them or be the marketing dumb logic move of the century 😅

We can only hope. With GM's drive to simplify their Bills of Materials and the Hummer going down the same production line, wouldn't they standardize the drives for all the EV trucks. The Hummer dual motor has mechanical lockers so it should be a breeze to include lockers on the SEVs. As you say, it would be a dumb marketing move not to but the pencil pushers might want to soak us for more money as ZR2/AT4X options. Even if so, why not make those available now?

I am still scratching my head as to what "hydraulic rebound control" might be.

 

[nebula1701]

We can only hope. With GM's drive to simplify their Bills of Materials and the Hummer going down the same production line, wouldn't they standardize the drives for all the EV trucks. The Hummer dual motor has mechanical lockers so it should be a breeze to include lockers on the SEVs. As you say, it would be a dumb marketing move not to but the pencil pushers might want to soak us for more money as ZR2/AT4X options. Even if so, why not make those available now?

I am still scratching my head as to what "hydraulic rebound control" might be.

They use the same terminology on the Dampers for the 2024-25 Travers and Acadia off-road trims.

 

[flyinglow]

They use the same terminology on the Dampers for the 2024-25 Travers and Acadia off-road trims...

Tried to find something on the net that explains what it is but no luck. Any idea what it was on the Travers/Acadia? Shocks/dampers obviously control rebound hydraulicly. So, what is different from a normal shock absorber?

 

[SilverDan]

Well well well …

How to use locking differentials

Your vehicle must be in Terrain Mode or the 4Lo transfer case setting (if equipped) to engage both the front and rear lockers. On some vehicles, such as the Chevrolet Silverado EV, the button must be held down for at least 5 seconds to engage both lockers.

This is a page about using lockers and EV’s, on the Chevy site. Could be a typo (but a really weird one?) or an inadvertent leak. Also an article about how to use Sidewinder mode

 

[flyinglow]

Well well well …
This is a page about using lockers and EV’s, on the Chevy site. Could be a typo (but a really weird one?) or an inadvertent leak.

Verrrry Interesting...great catch!

Encouraging. At some point lockers should be available...but when? If it weren't on a Chevrolet site I might go with typo since the Hummers have lockers but, with this being webpages specifically about EV driving on a Chevy site I am more inclined to think it is a publication getting ahead of the vehicles being in public.

 

[SilverDan]

I checked the Wayback Machine for this page. It's been around unchanged since 2023 with just very generic information about diffs and lockers, only the Hummer EV is mentioned and the icon is shown for the rear lockers only. The last snapshot was Feb 14 of this year with no changes. So these edits are post Feb and not captured by Wayback yet.

So somebody came into these pages in the last three months and added instructions on how to use them for the Silverado EV specifically. I'll call that practically definitive and say we're going to see dual lockers 🎉🎉🎉

before

after

 

[SilverDan]

Taking a closer look, they just swapped "Silverado EV" for "GMC HUMMER EV", added the front/rear icons, and touched up the formatting. Obviously the Hummer was a placeholder and that was probably always the intent, they designed the help pages originally knowing lockers were coming.

For reference here's the Hummer Quick Start guide for lockers

 

[nebula1701]

https://www.reddit.com/r/HummerEV/s/M2T9uP1lvX

And this 3X SUV doesn't have the Off-road package.

 

[SilverDan]

Impressive - lockers really work even and especially for non rock climbing.

 

[flyinglow]

Taking a closer look, they just swapped "Silverado EV" for "GMC HUMMER EV", added the front/rear icons, and touched up the formatting. Obviously the Hummer was a placeholder and that was probably always the intent, they designed the help pages originally knowing lockers were coming.

For reference here's the Hummer Quick Start guide for lockers

Corresponding button on the center stack...sounds like a physical button, not just something in the UI menu.

 

[nebula1701]

Corresponding button on the center stack...sounds like a physical button, not just something in the UI menu.

yeah the img SilverDan posted is for the Hummer and it has 2 physical buttons for the front and rear lockers.

 

[SilverDan]

As far as I can see it's the same approach, they both use the 'wait 5 seconds' wording. I'm guessing they'll use one of the left hand side buttons for lockers, at this point will take it as one button, long press to get both lockers.

TB and AT4 presumably will be the same, with the airbag button replaced by a single locker button with long press.

Somewhere I saw some wording around Terrain mode on those web pages, maybe that mode will automatically engage the lockers? Probably take an approach similar to the Hummer whatever that does.

 

[SilverDan]

So what's the logic behind the fact that the front lockers can only be used if the back are engaged? The back do less work as they're not a steering axle for most vehicles. Except the TB/AT4 have rear steer, so both are steering axles.

 

[nebula1701]

So what's the logic behind the fact that the front lockers can only be used if the back are engaged? The back do less work as they're not a steering axle for most vehicles. Except the TB/AT4 have rear steer, so both are steering axles.

You want it on the rears first because when climbing hills more weight will be transferred to the rear wheels than the front, it will transfer more weight, traction and drive to the rear wheels to help push you up.

 

[VAF84]

Better handling and with a smoother ride.

Btw, any major impact on efficiency? Found a nearby shop with Hummer EV 18" Takeoff's that have tires sized 305/70/18. In my case I'm assuming maybe a possible gain in efficiency vs 24's, but just curious as to your experience.

 

[Marvin]

I am still scratching my head as to what "hydraulic rebound control" might be.

It's a damper (shock absorber for many Americans) that has electronically adjustable valving on the rebound circuit. The Cybertruck has electronically adjustable damping on both the compression and rebound circuits (two electro-valves per damper). It adjusts the damping on the fly, based upon the action of the shock absorber, amongst other things.

 

[Suburban]

Btw, any major impact on efficiency? Found a nearby shop with Hummer EV 18" Takeoff's that have tires sized 305/70/18. In my case I'm assuming maybe a possible gain in efficiency vs 24's, but just curious as to your experience.

My experience with the 305/70-18 is about .1-.2 mpKWh loss compared to the factory 24" wheels and tires. The 285/75-18 Nokian severe snow rated tires I replaced the Hummer Goodyears with didn’t change it.

 

[VAF84]

My experience with the 305/70-18 is about .1-.2 mpKWh loss compared to the factory 24" wheels and tires. The 285/75-18 Nokian severe snow rated tires I replaced the Hummer Goodyears with didn’t change it.

Woof...I don't know if I can lose any more efficiency with my driving style and 80% freeway driving. Good thing these have such great range, because I'll still consider it. I didn't dream of modifying my prior Lightning, I needed every last mile of range

So it's a tough call. I can get Hummer EV take offs with basically new stock tires for $1,800. However, I was thinking maybe I can just find some other 18's and get something like a 270/70/18; that would make it the same width as the current tires. I just don't know if it will look funny.

That said, it'd also be more expensive to do that, making this whole thing a moot point as I'm not trying to spend a ton here. Just don't want my truck to stand out as much on the job sites, or during long road trips.

 

[spiritedEV]

Btw, any major impact on efficiency? Found a nearby shop with Hummer EV 18" Takeoff's that have tires sized 305/70/18. In my case I'm assuming maybe a possible gain in efficiency vs 24's, but just curious as to your experience.

Just drove today about 150 miles at 80mph, very hilly, and scored 1.7 mpkh. In town, usually 2.2. May try 70 mph on the way home. No meaningful loss for me if there is any. The truck is just better with them. Have hard tonneau as well.