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Posted

So I'm probably going to order me a 3500 LT here soon and I'm trying to figure out if paying for the autotrac transfer case is worth it. 

 

Is there any difference between the regular transfer case and autotrac other than 4 Auto? One stronger than the other?

 

Anyone really use 4 Auto? 

Posted

I dont know if there is a mechanical or strength difference. I am in the market for a 2020+ GM HD so I'm wondering the same thing. I have the auto4x4 in my 1500 Sierra and I use it all the time. Its really nice if you live in an area where road conditions vary. Colorado high country is a good example. 

Posted (edited)

I've had several 2500 and 3500 GM trucks since 2005.  Personally, I prefer the AutoTrac transfer case.  The 2020 GMC Sierra HD Denali that I currently own has it and it is the first 2500 I've owned that has it.  I have no information if it is more reliable or rugged than the regular four wheel drive transfer case, but I know that I don't like the "bucking" that occurs when turning the steering wheel when in four wheel drive with the old transfer case.

Edited by Thankful
Correct
Posted

I would bet strength wise they are equal

 

the newer versions offering AUTO are nice as stated for general driving in varying conditions with no front tires fighting each other on tight turns with somewhat snowy / less snowy roads, and having the option of full 4WD for constant snow plowing ...

 

I've had 3 HD's 2004/2011/2015 all with electric shift (all bought new & used by me for over 100,000 miles) and have never had a failure

 

I believe in AUTO mode the truck is just rear wheel drive and as rear slippage is sensed the fronts smoothly engage as needed - thats how my 2007 Avalanche worked - I liked it

 

30 years ago I'd say there were issues with the Electric, but now all mine have been flawless

 

some general info I found

 

https://tnttransfercase.com/general-motors-transfer-cases/

Posted

So I assume the transfer case internals are the same either way, it's just the Autotrac version has the ability to let that clutch pack slip? It's not like the regular version has a solid gear set that engages?

  • Like 1
Posted

One advantage of Autotrac is not having to worry about forgetting to take the truck out of 4WD.  Leaving the system on won't damage anything whereas leaving 4WD engaged could potentially snap and axle or damage the transfer case itself if driving on a hard, dry surface.  that's an extreme example but it does happen occasionally.

Posted (edited)

Seems to be some confusion about the different transfer cases. 

 

The older transfer case with the floor shift.

The version with the knob controlled electronic shifter that has been available for a bunch of years now.

 

The 'autotrac' box, which is new on HD's starting in 2020, although 1500's have had an autotrac box for a number of years. 

Autotrac has the additional mode where the truck decides when it should engage the transfer case. 

 

These two have been in use for a number of years:

NQG    Transfer case, with floor-mounted shifter
NQF    Transfer case, electronic shift with rotary dial controls 

 

Starting in 2020 we have modified controls on NFQ, and NQH Autotrac has been added.   NQG Floor shifter gone. 

NQF    Transfer case, two-speed, electronic shift with push button controls
NQH       NEW!  Transfer case, two-speed active, electronic Autotrac with push button control
 

Edited by redwngr
  • Thanks 1
Posted
9 hours ago, redwngr said:

Seems to be some confusion about the different transfer cases. 

 

The older transfer case with the floor shift.

The version with the knob controlled electronic shifter that has been available for a bunch of years now.

 

The 'autotrac' box, which is new on HD's starting in 2020, although 1500's have had an autotrac box for a number of years. 

Autotrac has the additional mode where the truck decides when it should engage the transfer case. 

 

These two have been in use for a number of years:

NQG    Transfer case, with floor-mounted shifter
NQF    Transfer case, electronic shift with rotary dial controls 

 

Starting in 2020 we have modified controls on NFQ, and NQH Autotrac has been added.   NQG Floor shifter gone. 

NQF    Transfer case, two-speed, electronic shift with push button controls
NQH       NEW!  Transfer case, two-speed active, electronic Autotrac with push button control
 

No confusion here. I know the floor shift is gone.

 

All I'm trying to figure out is if the ONLY difference is the fact the Autotrac has the extra 4A setting along with the electric motor that can allow varying degrees of clutch pack engagement. 

 

I would assume they wouldn't use 2 different transfer cases. One with a solid gear hookup, ans one with clutch pack engagement 

Posted
50 minutes ago, redwngr said:

They are different transfer cases. 

 

 

Where are you finding this? Everything I'm finding essentially says the 2 transfer cases are the same, one simply has the capability to vary clutch pressure, therefore accomplishing 4A 

Posted (edited)

https://gm-techlink.com/?p=11710

 

Welcome addition to the HD models.  I hope Ford and Dodge follow.  The 1/2 ton rams use the same 1500 GM autotrac tcase in some models.  I like the GM offers the autotrac historically even on the LT 1/2 tons vs Ford (late to the game, offer only on lariat+, and still using vacuum hubs?).

 

Should be reliable, assuming you're not plowing with it in 4auto, but fine for daily driving.

Edited by sabre364
Posted (edited)

GM has had the Autotrac version on the 1500's for a bunch of years.

It's new to the HDs for 2020. 

 

On current HD's, the LT and SLE are the only trims that can have either box.

Lower only get the NQF, higher only get the NQH

 

 

FWIW, the 1500's now have an autotrac box that doesn't have 4Lo as std on lower trims.

NP0    Transfer case, single speed, electronic Autotrac with push button control (4WD models only)

 

 

 

 

Edited by redwngr
  • 4 years later...
Posted

This thread is a few years old, but seems to be on topic for me.  I am looking at 2024/2025 Silvarado 1500 4x4. The 2spd transfer case option is a $200 upgrade. With this selectorI can chose 2 hi, 4hi, and 4lo. Where as the Auto has 4 hi setting and Auto that kicks in as it determines. More like an adaptive AWD, than a true 4wd. If someone could clear this up for me I would appreciate it. 

Posted

The auto has a clutch pack in it. When it is in auto, it holds at like 10 or 15% until rear wheel slip happens, then it engages. It's worth the money if ordering a truck. Most main roads are plowed and dry-ish and side streets are not in snowy city areas (like Flagstaff or east of the Rockies). Constantly switching in and out *could* be annoying if you live there. If you just visit like me, it's not a big deal. Push a button, done. I would have checked the box if I ordered my truck though. 

Posted
On 1/6/2025 at 3:09 PM, Skiff Lowrey said:

This thread is a few years old, but seems to be on topic for me.  I am looking at 2024/2025 Silvarado 1500 4x4. The 2spd transfer case option is a $200 upgrade. With this selectorI can chose 2 hi, 4hi, and 4lo. Where as the Auto has 4 hi setting and Auto that kicks in as it determines. More like an adaptive AWD, than a true 4wd. If someone could clear this up for me I would appreciate it. 

Both the single speed and two speed transfer cases have the “auto” function as described above. Both have 4 hi, which is a true part time  4 wheel drive with no center differential or slippage function. The two speed transfer case also has 4 wheel drive low, or 4 Lo, which significantly changes the overall drive gear ratio to provide greater torque and speed control while driving on unpaved or slippery surfaces.  


To me it makes no sense not to get the two speed transfer case. It’s probably one of the only features that is worth 5 to 10 times what you paid for it at resale because many people will not even consider the truck if it doesn’t have 4 Lo.). It is essential for off roading and for gardening (stump pulling), and really nice to have for steep boat ramps.  Most people not off roading or using steep boat ramps rarely use it, but when you need it, you will be very glad you spent that $200. 

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