K1500 AWD SWAP

[Marshall Cameron]

I've got a 97 GMC K1500 short bed. Wondering if anyone has heard of or done an AWD swap? Apparently you can rob a 2002-2006 Escalade AWD of its front diff and transfer case (NV149) and its as easy as bolting in the Escalade parts onto your truck. Thoughts and ideas for making this happen is accepted

 

[stutaeng]

Yes, definitely possible. Have you seen that K1500 on Powernation? It was project "Red Tide."

xc_hide_links_from_guests_guests_error_hide_media

 

[PlayingWithTBI]

Yeah, and then he took it out and broke it, ha ha. IIRC they were selling that truck for ~$25K?

 

[alpinecrick]

Why not an Autotrack system from a GMT400 Suburban/Tahoe?

 

[Nad_Yvalhosert]

Why not an Autotrack system from a GMT400 Suburban/Tahoe?

Tahoe/Suburban NEVER came with Autotrac.
Autotrac is on the smaller SUV's like the Chevy Equinox. Primarially wrong wheel drive, electrically activating rear differentials

Do you mean the Bravada/Astro vehicles? Those systems use wheel speed sensor input from the front bearing assemblies, through a computer module, to shift the t-case. It's a special case with a built in Viscous coupler. Its not available in the GMT400

Now, if you mean the auto engaging 4x4 NV243 t-case, again it doesnt have a viscous coupler and locks the speed of the front and rear drive shafts... a BIG NO-NO on dry pavement.

Best option is the NV149 t-case from the GMT800 AWD Denali, Escalade... Completely self contained, full time case, viscous coupler, no electronics needed. Direct bolt in to the 4L60, but you'll need to replace the front drive shaft with a dual carden joint, then lock the front diff, or replace it with a newer diff

If you use the GMT800 front diff, be aware that the case is usually a 4:10 gear and the pass side mount needs to be fabricated. It's at a different angle and wont directly bolt to the 400 mount. Again pointed out by LT on the Red Tide episode of Truck Tech

Lastly, chances are the OP's '97 already has the NV243 case and has the Auto position...

 

[Nad_Yvalhosert]

I've been looking into this for a while. Plans are for my 38k original mile, Whipple supercharged 5.7, manual tranny, 1989 K1500, to receive a 3-4 lowering kit, and the NV149.

It'll make a helluva summer only street truck, considering I already have a first gen Denali daily driver, 2500 Suburban plow truck, and very first 4x4, my 'ole 1988 Sierra stepside

Now, on my end, the 31 spline count of the 5 speed matches the TH400/4L80, and the NV149 uses the 27 spline like the 700r4/4L60.

But, I've found a guy that fabricates a new input gear to perform the t-case swap, like LT did Truck Tech did on Project Red Tide with the 4L80

 

[alpinecrick]

Tahoe/Suburban NEVER came with Autotrac.
Autotrac is on the smaller SUV's like the Chevy Equinox. Primarially wrong wheel drive, electrically activating rear differentials

Do you mean the Bravada/Astro vehicles? Those systems use wheel speed sensor input from the front bearing assemblies, through a computer module, to shift the t-case. It's a special case with a built in Viscous coupler. Its not available in the GMT400

Now, if you mean the auto engaging 4x4 NV243 t-case, again it doesnt have a viscous coupler and locks the speed of the front and rear drive shafts... a BIG NO-NO on dry pavement.

Best option is the NV149 t-case from the GMT800 AWD Denali, Escalade... Completely self contained, full time case, viscous coupler, no electronics needed. Direct bolt in to the 4L60, but you'll need to replace the front drive shaft with a dual carden joint, then lock the front diff, or replace it with a newer diff

If you use the GMT800 front diff, be aware that the case is usually a 4:10 gear and the pass side mount needs to be fabricated. It's at a different angle and wont directly bolt to the 400 mount. Again pointed out by LT on the Red Tide episode of Truck Tech

Lastly, chances are the OP's '97 already has the NV243 case and has the Auto position...

Autotrac(k) never came in pickups in the GMT400's. I think you might be confusing pushbutton 4wd with the Autotrac feature.

Suburbans/Tahoes with Autotrac were in 2hi, or Autotrac (billed as a fulltime 4wd regardless of driving surface), or locked in 4hi or 4lo. In 4hi/4lo is the only time both driveshafts are locked together. In other words Autotrac was designed for on pavement but less than dry conditions. There is some kind of coupler in the Autotrac transfer case, that's why the blue ATF fluid was required.

 

[Nad_Yvalhosert]

Autotrac(k) never came in pickups in the GMT400's. I think you might be confusing pushbutton 4wd with the Autotrac feature.

Suburbans/Tahoes with Autotrac were in 2hi, or Autotrac (billed as a fulltime 4wd regardless of driving surface), or locked in 4hi or 4lo. In 4hi/4lo is the only time both driveshafts are locked together. In other words Autotrac was designed for on pavement but less than dry conditions. There is some kind of coupler in the Autotrac transfer case, that's why the blue ATF fluid was required.

Blue, yup. Both the NV 243 in my Denali, and the NV 263 in Suburban 2500 take red fluid.
The switch is labeled 2Hi, 4Hi, Auto, 4Lo
Neither the 243 and the 263 have Viscous couplers. Therefore NOT for use on hard packed surfaces. As stated in my owner's manuals...
Rule of thumb is, if there's a way for the operator to switch between 2wd and 4x4, it isnt fulltime. If there is no switch, its fulltime

And the mode on the switch is Auto, not Autotrac. As in automatically engaging 4x4. It's not a Chrysler Quadratrac... GMT400 t-cases do not have a way to "slip", allowing the tires to spins different speeds around a corner

Please, show me where it states it can be used in a Fulltime 4x4 mode

 

[alpinecrick]

Blue, yup. Both the NV 243 in my Denali, and the NV 263 in Suburban 2500 take red fluid.
And neither the 243 and the 263 have Viscous couplers. Therefore NOT for use on hard packed surfaces. As stated in my owner's manuals...

And the mode on the switch is Auto, not Autotrac. As in automatically engaging 4x4. It's not a Chrysler Quadratrac... GMT400 t-cases do not have a way to "slip", allowing the tires to spins different speeds around a corner

Maybe I be wrong then. I do think the AutoTrac feature allows for driving on alternating dry-slick pavement. Doesn't Autotrac lock/unlock the front driveshaft? As opposed to the Quadratrac type system which does allow the driveshafts to turn at different speeds?

 

[alpinecrick]

Where the heck is df when I need him.............