Single Speed Transfer Case

SummitWhiteT1 · January 15, 2020

Has anyone gone off roading/camping with the new Single Speed Transfer Case? I didn't realize it until after I bought my truck that I don't have 4 lo and I am worried that I might need it. I don't go rock crawling but I worry about getting stuck in the dunes/mud and rough terrain trails

davester · January 15, 2020

What would you do with anyones post?

They would either post

I did X and got stuck

or

I did X and didn't get stuck

And if the person got stuck, having 4Lo may or may not have made a difference, or it could just be lack of skill of the driver.

It comes down to driver knowing what to do, and being prepared when things go wrong.

MacLaren · January 16, 2020

Living in the mountains all my life, I made damn sure I had 4 LO.

Been stuck in 4 HI too many times to be bailed out by 4 LO.

But, that's just me.

I cannot though, figure out why GM even offers 4 HI only in their trucks....

Praedator · January 16, 2020

4lo is only needed needed when the low gearing is needed for that low end torque etc... I've only used it to pull something out. If I'm stuck in 4hi, 4lo isn't going to help in mud, snow, loose traction situations. The rear locker and more spinning wheels help there.

It also does help going down loose paths with a large grade to crawl slower and have better control.

But it's one of those things that you will hardly use but wish you had it when needed though.

Sent from my XT1710-02 using Tapatalk

SummitWhiteT1 · January 16, 2020

dang so what's the point of just having 4hi? Seems like it's just AWD but without running full time. Feel like the truck is going to be useless off road now

Edited January 16, 2020 by SummitWhiteT1

swathdiver · January 16, 2020

4HI is generally for snow, rain, light off-road, etc. So GM used it with 3.08 gears to keep their gas mileage high on the 900s. The trucks with max towing capacity got the lower gears (higher number) and 2-speed TC.

redwngr · January 17, 2020

Switched from 2wd to 4wd GM pickups about 25 years ago.

Can honestly say I've still not found a reason I needed to use 4LO.

(Besides, it's a nuisance to stop to be able to engage it instead of shifting on-the-fly.)

2 years in and I've never even bothered to see if 4LO it would engage on the current truck.

Obviously, that won't be the case for all 4wd users.

I'm not a fan of Auto 4wd either, so adding Autotrac to the HD's starting with 2020MY doesn't interest me.

OnTheReel · January 17, 2020

Love Auto 4x4 and I think it’s a real great improvement for the HDs, even though it hasn’t gotten much attention. It is just the perfect mode for this time of year around here. In the 2-3 days following a storm...some roads plowed clear and dry, other roads and parking lots still have a lot of ice and slop. Perfect conditions to just leave it in auto and not even worry about it. Beats switching back and forth, or potentially forgetting it’s in 4 high on a dry road and getting a nasty reminder.

I only use 4L if I’m pulling someone out of a ditch, or pulling a heavy boat out of a steep, slick ramp. The gear reduction does make a huge difference.

Still, it’s hard to think of any typical off-road scenario where I’d have my shiny new truck in a predicament requiring 4 low. I guess it’s nice to know it’s there but I wouldn’t say your truck is worthless off-road without it.

swathdiver · January 17, 2020

1 hour ago, redwngr said:

Switched from 2wd to 4wd GM pickups about 25 years ago.

Can honestly say I've still not found a reason I needed to use 4LO.

(Besides, it's a nuisance to stop to be able to engage it instead of shifting on-the-fly.)

2 years in and I've never even bothered to see if 4LO it would engage on the current truck.

Obviously, that won't be the case for all 4wd users.

I'm not a fan of Auto 4wd either, so adding Autotrac to the HD's starting with 2020MY doesn't interest me.

We use 4LO when playing around in the woods and sometimes out on the beach but 4HI is usually enough, especially with KO2s. REALLY nice to have 4LO on slippery boat ramps.

4AUTO is nice for peace of mind when my wife or daughters are driving the truck in the rain. I looked up the government crash statistics for my truck and the death and serious injury rate while already low, was 1/2 as much in the 4x4s and AWD trucks compared with RWD.

Edited January 17, 2020 by swathdiver

newLT290 · January 17, 2020

with the single speed transfer in sport mode emulates a lo range... according to the gm owners manual..i personally have not tried it yet..as others stated in 40 yrs of 4x4 trucks i have used low range very limited times mainly going slow back down mountain passes ..and yes i can get stuck in high range quite sufficiently . Btw i do not agree with GM's choice to put the single speed in however

Edited January 17, 2020 by newLT290
added

SummitWhiteT1 · January 17, 2020

I'm going to have to test it out and see if it is sufficient using "emulated" lo range. I would imagine that these trucks have enough torque that it's probably the slow crawl in 4lo and not the actual gear reduction that helps you out of a tough situation. So in theory the "emulated" lo range should be sufficient since it turns off traction and modulates the brakes

redwngr · January 17, 2020

4 hours ago, newLT290 said:

with the single speed transfer in sport mode emulates a lo range... according to the gm owners manual..i personally have not tried it yet..as others stated in 40 yrs of 4x4 trucks i have used low range very limited times mainly going slow back down mountain passes ..and yes i can get stuck in high range quite sufficiently . Btw i do not agree with GM's choice to put the single speed in however

Except for Silverado Custom, the 2 speed box is either standard or available on all trims.

On Sierra, the 2 speed transfer case is either standard or available on all trims.

Both 1500 transfer cases have Autotrac.

On the HD's, all transfer cases are 2 speed.

Higher HD trims (for the first time, in 2020) have Autotrac (which is optional on SLE and LT)

Edited January 17, 2020 by redwngr

Thomcat · January 17, 2020

1 hour ago, SummitWhiteT1 said:

I'm going to have to test it out and see if it is sufficient using "emulated" lo range. I would imagine that these trucks have enough torque that it's probably the slow crawl in 4lo and not the actual gear reduction that helps you out of a tough situation. So in theory the "emulated" lo range should be sufficient since it turns off traction and modulates the brakes

5 hours ago, newLT290 said:

with the single speed transfer in sport mode emulates a lo range... according to the gm owners manual..i personally have not tried it yet..as others stated in 40 yrs of 4x4 trucks i have used low range very limited times mainly going slow back down mountain passes ..and yes i can get stuck in high range quite sufficiently . Btw i do not agree with GM's choice to put the single speed in however

I believe that the Z71 option w/2 spd transfer case is not compatible with RST builds which instead come standard with 4 driving mode (touring, trailer, sport and off road) operation.

Sport mode (checkered flag icon) does not emulate 4Lo, merely adjusts shift points upward. RSTs, stock with a single speed transfer case and 4 driving mode option, have an Off Road button replacing the 4Lo button. The Off Road (lower right) button will simulate the speed/gearing of 4Lo position in the two speed transfer case; but, without the same amount of torque.

redwngr · January 18, 2020

9 hours ago, Thomcat said:

I believe that the Z71 option w/2 spd transfer case is not compatible with RST builds which instead come standard with 4 driving mode (touring, trailer, sport and off road) operation.

Sport mode (checkered flag icon) does not emulate 4Lo, merely adjusts shift points upward. RSTs, stock with a single speed transfer case and 4 driving mode option, have an Off Road button replacing the 4Lo button. The Off Road (lower right) button will simulate the speed/gearing of 4Lo position in the two speed transfer case; but, without the same amount of torque.

On RST, the single speed is stndard.

Currently on 2020, the two speed is included if Z71 is added to the RST .

NQH Transfer case, two-speed, electronic Autotrac with push button control (4WD models only)
On WT - Included and only available with (Z71) Z71 Off-Road Package. Free flow requires Regular Cab model.
On LT - Included and only available with (Z71) Z71 Off-Road Package.
On RST and LTZ - Included and only available with (Z71) Z71 Off-Road Package or (L87) 6.2L EcoTec3 V8 engine.

Standard on Custom Trail Boss, LT Trail Boss and High Country

Not available on Custom

Edited January 18, 2020 by redwngr

SummitWhiteT1 · January 28, 2020

Are the z71 trucks and single speed trucks identical other than the transfer case and skid plates? I wonder if it would be possible down the line to swap in the two speed transfer case (assuming you could reprogram the BCM and that all other mechanical bits are identical)