Figure I’ll ask this question here because it’s 4wd related.

[Imlow78]

Will a NP246 for hold up with 4L80E and power.

I’m currently looking at doing a 4l80e swap in my 05 z71 and want to keep it 4wd but throw some power to it when I turbo the 5.3 until I build a 6.0 for boost.

I hate the push button 4wd but kinda trying to keep everything looking stock and functioning the same way.

Also is there a better front diff that will bolt in that has a bigger diameter ring gear? I didn’t know if a unit out of a 2500 would be better and would work with minimal to no fabrication?

Need some help here. Thank you guys!

Shannon

 

[S33k3r]

I do not have enough information on what I actually have, but if I can provide information you think might be useful, please ask. I have a 2003 Sierra Denali; it has a 149. I *think* my 2004 Silverado 2500 and my 2005 Suburban 2500 both carry the NP246, but can't look right this minute. The two, newer trucks both run 6.0s and the 4L80E transmission. When I get a chance, I'll go verify the transfer case on the Silverado. The transfer case for the Suburban is at my wife's work -- along with my wife and the rest of the Suburban...

I hope that information helps a little.

 

[swathdiver]

Will a NP246 for hold up with 4L80E and power.

I’m currently looking at doing a 4l80e swap in my 05 z71 and want to keep it 4wd but throw some power to it when I turbo the 5.3 until I build a 6.0 for boost.

I hate the push button 4wd but kinda trying to keep everything looking stock and functioning the same way.

Also is there a better front diff that will bolt in that has a bigger diameter ring gear? I didn’t know if a unit out of a 2500 would be better and would work with minimal to no fabrication?

Need some help here. Thank you guys!

Shannon

Randy has done both differential swaps and documented them on this forum. I believe that he has also done the transfer case too. @randeez

LT has also done it and documented it when he was on Powernation TV and on his own youtube channel: https://www.youtube.com/user/lawrencetolman/videos

 

[Imlow78]

Thank you guys! I’m trying to build the ground work for reliability and solving weak links before adding a bunch of power.

Shannon

 

[swathdiver]

Thank you guys! I’m trying to build the ground work for reliability and solving weak links before adding a bunch of power.

Shannon

Do you want the larger front differential for drag racing in 4WD?

 

[Imlow78]

Do you want the larger front differential for drag racing in 4WD?

Yes. Kinda the reason I’m looking for 4l80 and better/stronger transfer case also.

Hoping to ultimately make 1000+ when it’s time to play and conservatively drive it with 650hp.

Prolly end up wit a 9” center in the rear or 12bolt. I know the weakness of a 12bolt over 9” but it takes less hp to spin the 12bolt.

If I do a 9” I already have a new aluminum MW bolt through center chunk with 4.30 polished gear set. But if I do the 9” it will have 40 spline gun drilled axles and lightened flanges if the weight and HP of the truck isn’t too much to do that.


Shannon

 

[swathdiver]

Yes. Kinda the reason I’m looking for 4l80 and better/stronger transfer case also.

Hoping to ultimately make 1000+ when it’s time to play and conservatively drive it with 650hp.

Prolly end up wit a 9” center in the rear or 12bolt. I know the weakness of a 12bolt over 9” but it takes less hp to spin the 12bolt.

If I do a 9” I already have a new aluminum MW bolt through center chunk with 4.30 polished gear set. But if I do the 9” it will have 40 spline gun drilled axles and lightened flanges if the weight and HP of the truck isn’t too much to do that.


Shannon

Fun stuff! Well be sure to pick the brains of @01ssreda4 @67RS427 and @randeez as they have all been down this path in one form or another.

 

[randeez]

for a gmt800 the (pre-2010) 9.25ifs doesnt swap easily into a 1500 iirc. the clamshell style case is completely different than a 2011+ that i swapped into my gmt900 (this wouldnt swap either) a long time ago a company used to make brackets to put the clamshell style ifs into a 1500 but it was 100% directed at lifted and offroading and accommodated a lift as well so it wouldnt be good anyway. i would just run what you have till it breaks - some never have problems.

the only traction aide i could find that works in a 9.25 is a ratcheting style locker that replaces the spider gears for my year front diff. for the older diff i dont think i ever actually found someone who's done it but supposedly theres a eaton elocker that "should" work but its 1200$+ if you can even find one.

4l80 is a good idea, pretty much any transfer case from a 2500 or 6l80 1500 will work (33spline input) all the transmission adapters use the same 6bolt pattern. i say pretty much because newer 6l90 4x4s use a 36spline input i think. i imagine you could keep make an electronic shifted trans work from a 2500 in a 1500 might take moving some pins around but its doing the same action i dont see why it couldnt work. i dont know which is best cause i dont plan on using them.

rear end , having a 3rd member style would be nice for changing gears but regearing the front diff repeatly would suck lol or just collect/build a front diff in each ratio. and the whole rear would have to be fab'd. the 14bolt 9.5 SF bolts right in with zero fab work.
other "problem" with 9.25ifs is gearing - currently have 4.10s in mine and im about out of gear going thru the traps @140+mph and 6500rpm+. longest ratio is a 3.42 which would get me to about 170 in 3rd gear (1:1 in a 4l80) which "should" be unobtainable but if i wanted to do a 1/2 mile even or something good chance it would break that barrier.

 

[Imlow78]

for a gmt800 the (pre-2010) 9.25ifs doesnt swap easily into a 1500 iirc. the clamshell style case is completely different than a 2011+ that i swapped into my gmt900 (this wouldnt swap either) a long time ago a company used to make brackets to put the clamshell style ifs into a 1500 but it was 100% directed at lifted and offroading and accommodated a lift as well so it wouldnt be good anyway. i would just run what you have till it breaks - some never have problems.

the only traction aide i could find that works in a 9.25 is a ratcheting style locker that replaces the spider gears for my year front diff. for the older diff i dont think i ever actually found someone who's done it but supposedly theres a eaton elocker that "should" work but its 1200$+ if you can even find one.

4l80 is a good idea, pretty much any transfer case from a 2500 or 6l80 1500 will work (33spline input) all the transmission adapters use the same 6bolt pattern. i say pretty much because newer 6l90 4x4s use a 36spline input i think. i imagine you could keep make an electronic shifted trans work from a 2500 in a 1500 might take moving some pins around but its doing the same action i dont see why it couldnt work. i dont know which is best cause i dont plan on using them.

rear end , having a 3rd member style would be nice for changing gears but regearing the front diff repeatly would suck lol or just collect/build a front diff in each ratio. and the whole rear would have to be fab'd. the 14bolt 9.5 SF bolts right in with zero fab work.
other "problem" with 9.25ifs is gearing - currently have 4.10s in mine and im about out of gear going thru the traps @140+mph and 6500rpm+. longest ratio is a 3.42 which would get me to about 170 in 3rd gear (1:1 in a 4l80) which "should" be unobtainable but if i wanted to do a 1/2 mile even or something good chance it would break that barrier.

I think I’m going to have Jakes Transmission build the 4l80 for me.

I agree the 9” would be great. Wish someone made a fabricated front diff that used a 9” chunk that bolted in. But I guess I could see if Reese brother or another shop might be able to build one if I really wanted to go that route.

For now I’m going to try and stick with bolt in stuff till it starts braking. LoL

Thank you for your input on this matter.


Shannon

 

[Fjs0001]

The BW4485 out of the 2007+ Denali and Escalades can take a lot of abuse. It bolts right up to the 4l80e, but you lose low range. You also need the rear half of a BW4481 out of a 2003~2006 Denali or Escalade for the speed speed sensor and rear output shaft.