Can you install a 2 speed transfer case in to a vehicle with a single speed?

[MagicMike]

WOW! Thanks guys! I'm looking to switch my 2013 Tahoe from the 1 speed TC to a 2 speed TC. From what everyone has described, I think I can do it. Plus it almost gives me an excuse to throw a 4" BDS lift on since that kit requires cutting and welding!

 

[mrpeterclark]

I know this is an old thread and my situation is a little different, but hoping someone knows the answers. I have a Denali (AWD) and want to swap to a 2 speed transfer case. I'm REALLY hoping GM used the same wiring harness in the Denali and just left the wires taped up behind the dash (there is a little niche where the selector switch goes on the other models) Trying to find out if anyone has ever done this. I think the AWD case may be a different dimension in which case I'll also need shorter/ longer drive shafts, but if a TCCM, switch and Transfer case and switches and maybe shafts from a donor is all I need that would be AMAZING!

And you've got two guys here who've done it already, Charles and Justin, should you have any questions.

 

[swathdiver]

I know this is an old thread and my situation is a little different, but hoping someone knows the answers. I have a Denali (AWD) and want to swap to a 2 speed transfer case. I'm REALLY hoping GM used the same wiring harness in the Denali and just left the wires taped up behind the dash (there is a little niche where the selector switch goes on the other models) Trying to find out if anyone has ever done this. I think the AWD case may be a different dimension in which case I'll also need shorter/ longer drive shafts, but if a TCCM, switch and Transfer case and switches and maybe shafts from a donor is all I need that would be AMAZING!

I don't think the driveshafts are any different, front or rear. You can check here by plugging in the different models and seeing what part numbers they use: https://parts-catalog.acdelco.com/acesCat.php?

I would think that even if the wiring is there, you have to do some programming to the various modules to make it all work factory like. Alternatively, a manual 2-speed case would work with removal of the center console and using the leather jump seat from the SLE pickups.

I know of a guy who has converted older 4x4s to AWD but not visa versa, he might know. That would be this fellow: https://www.youtube.com/c/LawrenceLTTolman

 

[mrpeterclark]

I don't think the driveshafts are any different, front or rear. You can check here by plugging in the different models and seeing what part numbers they use: https://parts-catalog.acdelco.com/acesCat.php?

I would think that even if the wiring is there, you have to do some programming to the various modules to make it all work factory like. Alternatively, a manual 2-speed case would work with removal of the center console and using the leather jump seat from the SLE pickups.

I know of a guy who has converted older 4x4s to AWD but not visa versa, he might know. That would be this fellow: https://www.youtube.com/c/LawrenceLTTolman

Thanks for the reply. I've thought about the manual swap, but I wasn't sure if the traction control would freak out or what other can of worms I would get into. I would need to figure out the Bose stuff that's built into the console, but that's not the end of the world. I've also seen some low profile shifters I might be able to sneak in right next to it. I think I would rather go the programming route if that is an option.

 

[mrpeterclark]

NP0 is the MP3010, single speed TC. This was introduced in 2010. 2007-2008 got the NVG246 (NP8) and the 2009s got the MP3023 (NQH). Curiously, there are two TCs for RPO NQH, the other is the MP3024 used in the 3/4-Ton trucks from 2008-2013. Function is the same, just a stronger unit which later rebuild kits for the 3023 include many parts from it standard now.

do you know if the 3023 and 3024 are the same size? the 3023 would have come mated to a 6L80 and the 3024 to a 6L90. Not sure if there are any differences that would make a 3024 not work in a 1500/ 6L80?
I'm determined to do this swap in my Denali next month while I'm waiting for my new motor to arrive. So far I've figured out what TCCM and Switch I need. I see the 3023 will work, but I might opt for the heavier duty 3024 if it works with the 3024 since I'm heavy and swapping in a new motor w/ 500 HP at the crank. I'm probably swapping out the tired front diff since I need new gears anyway. Might go for the bigger front diff as well. The big mistery is wiring harness(es). The Denali has no TCCM at all. Full time AWD and it doesn't talk to anything. I've seen a couple of guys put in manual t cases, but I've heard that Duraburb has swapped some Denalis to 4WD without too much trouble, and I much prefer that route. I just haven't been able to get the specifics from them yet and I need to move on it. It's possible GM put the same harness in all the trucks and just coiled up the ends in the AWD, but it's more likely similar to the 2WD. I'd rather just gather up the harnesses I need and be ready when I pull it all apart. Any idea where to look for wiring harness part numbers or what to look for on a donor?

 

[swathdiver]

do you know if the 3023 and 3024 are the same size? the 3023 would have come mated to a 6L80 and the 3024 to a 6L90. Not sure if there are any differences that would make a 3024 not work in a 1500/ 6L80?

That I do not know. I know that they have different input and output splines and the planetaries are different.

 

[randeez]

That I do not know. I know that they have different input and output splines and the planetaries are different.

6l90 uses a 29 spline input iirc, 6l80 uses a 32.
theres a write up on gmt900 site iirc..its a whole bunch of harnesses the transfer case also tells the front center axle disconnect to engage/disengage and wants feedback confirmation. the front awd axle doesnt have CAD

 

[nmtdriver]

do you know if the 3023 and 3024 are the same size? the 3023 would have come mated to a 6L80 and the 3024 to a 6L90. Not sure if there are any differences that would make a 3024 not work in a 1500/ 6L80?
I'm determined to do this swap in my Denali next month while I'm waiting for my new motor to arrive. So far I've figured out what TCCM and Switch I need. I see the 3023 will work, but I might opt for the heavier duty 3024 if it works with the 3024 since I'm heavy and swapping in a new motor w/ 500 HP at the crank. I'm probably swapping out the tired front diff since I need new gears anyway. Might go for the bigger front diff as well. The big mistery is wiring harness(es). The Denali has no TCCM at all. Full time AWD and it doesn't talk to anything. I've seen a couple of guys put in manual t cases, but I've heard that Duraburb has swapped some Denalis to 4WD without too much trouble, and I much prefer that route. I just haven't been able to get the specifics from them yet and I need to move on it. It's possible GM put the same harness in all the trucks and just coiled up the ends in the AWD, but it's more likely similar to the 2WD. I'd rather just gather up the harnesses I need and be ready when I pull it all apart. Any idea where to look for wiring harness part numbers or what to look for on a donor?

Any update? If this was possible, denalis and escalades with the NQH swap would be the ultimate gmt900s.