Bish

Yes, your description is exactly what I feel. In snow driving around a turn, front will start to plow, I'll give it gas and nothing immediately happens then it jerks like you say as if there was a delay in getting power to the front. My Tahoe was WAY better in 4Auto compared to this never mind 4HI. Disappointing. Still would like to findsoem type of operational spec for this thing. If I understand how it works, maybe I can compensate somehow.

Bostonsfavson

I agree with you fellas 100%. Glad it's not just me this time ;-)

ThatDudeOrion

I know this is a million year old thread, but I wanted to see if anyone has any updates about this topic.

Has anyone successfully swapped the NVG149 viscous coupling T-case in place of the BW4481/BW4485 open T-case in the newer GMT800 SUV's or GMT900 trucks and SUV's?

What were the issues, did it cause any codes, could they be deleted with Live or HPTuners?

Reason I'm asking is because I think a 03+ or particularly 06+ XLDenali would be really nice to have, but I want the NVG149 transfer case that was only offered in the XLD in 01-02. So the swap seems like the best way to go, not to mention its getting harder to find 01-02 XLD's or at least, ones that haven't been hacked up by Xzibit wannabes.

Wide Open

I'm not familiar with the specs of the NVG149 T-case but imagine it's doable. The 07+ AWD T-cases I've experimente with have all been self contained units (no sensors or wires). They only seem to send power forward when resistance is applied to the rear wheels. I had a '97 AWD Bravada that had a viscous coupling T-case that I liked much better. It didn't have any sensors either so something like that would probably work. Not sure if it's like a NVG149 or not.

EMX5636

I'm pretty sure the older Bravada/SyTy transfer cases were setup like the viscous 149 (I don't remember if the tq split is the same though). I haven't driven a GMT900 in the snow, but I'm really happy with the NVG149 in my C3.

I'm guessing that the open center diff only applies the front wheels by applying some rear brake?

Wide Open

My Bravada seemed to have about a 50/50 torque split. It would go through anything.
The new cases rely in the rear brakes being applied through Stabilitrac I think. They are probably fine in the vehicles they came in but about useless in everything else.

Visionxorb

Im in the same boat with our 07 yukon denali. we got this as the family truckster only to find out some dim whit at GM dropped the ball and specked out a bw4485 and now the only place i feel safe "trucking" the family to is the mall.

Whats different about the 6l80e vs the 4l60e and 4l80e. havent been able to find good physical comparison. would the NV149 4l80e adapter work? if a solution for this cant be found, what about mating something like a 242HD from an H1 and using some kind of cable actuator that we could hide under the dash.

Wide Open

The 6L80E is about an inch shorter than the 4l60E. I believe the 4L80E is a little bit shorter yet but not 100% sure on that one.
I believe all that would be necessary to mate the NV149 to the 6L80E would be swapping in the 80 input shaft but I haven't tried it myself.

Ming696

Digging this thread back up from the dead again. I'm getting ready to pull the trigger on a 2010 Sierra Denali and the more I read about the BW4485 the more I want to turn it into a boat anchor. Swapping in the NVG149 seems like the best option. Please tell me someone has done this. Another option I'm curious about is the BW 4484 used in the H2. It has a lockable center diff. Scroll down to bottom for 4484 info.

HUMMER

-Paul

98black2ss

I know this discussion was a while ago but I thought I would update. EAD still makes these input shafts and I have ordered three of them. We recently acquired a 2007 Yukon Denali for my wife. We love the truck with the 6.2L and the 6speed 6L80 but the transfer case blows big time. I am going to put one of the input shafts in a NV149 and put that in the 2007 Yukon Denali.

I spoke with Tim at
EAD Performance
15980 32 Mile
Ray, Michigan 48096

586-473-6538