04Denali

You mean there is something Butch doesn't know, I would have never thought would happen

Wide Open

Am I reading that the NV149AWD case can withstand 2203 lbs ft input torque????
I suppose that is engine torque * gear multiplication? If that is the true rating then it should theoretically handle about 550 lbs ft. That sound about right?

04Denali

mine handles the 805 ft lbs so far

Wide Open

I would love to keep AWD but would certainly like better traction than what I am currently getting. I read the earlier post and think that my unit requires excessive wheel spin before transferring adequate torque to the non-slipping wheels. It rocks on pavement though.

Bish

I stand corrected. Apparently the GMT900's (AWD) do not use the NVG149 any longer. I crawled under my Denali and it has a Borg Werner 4485 transfer case. I haven't been able to find much info on it yet but I'll keep looking.

Anybody know anything about the 4485?

Bostonsfavson

Nice job Bish! At least we know what we're dealing with. I've been wanting to get under the truck but it's just been too unpleasant here lately.

Bish

It's been bugging me since your post so I pulled into my warehouse to crawl under and see. I have found some references to this model but nothing with operational specs or anything about how it actually works. Borg Werner is actually a customer of mine so I'll see if the people we deal with know anything about it. Big company though, I'm not holding my breath.

Bostonsfavson

I've been looking, and I can't seem to find much information on this transfer case either. That's not exactly reassuring.

Bish

Me neither. However I did some testing this weekend as we had some nice weather for a change and some dry pavement. The more I play with it, the more disappointed I am in this transfer case. I was having an issue that was bugging me which I though was more traction control than anything. When accelerating hard, particularly around a slight turn, I would get wheel slip and the traction control would start modulating the brakes for me I thought it was traction control so I shut it off this weekend and it does the same damn thing. I'm starting to thing that it requires a stab on the rear brakes to engage the front. I have read that this t-case is an open differential design instead of a viscous coupling design. Not sure what that meant but if it takes a hit to the rear brakes to get more front power than it is a **** poor design IMO. I also have the front end puch in snow which leads me to believe that the front is NOT engaged all the time or if it is, it has so little power it does not work well.

I am in full agreement with you...compared to the NVG149, this new t-case is a pile of dog sh$t! Hoping to find some contradictory info but as you said, anything is tough to find on this thing.

Found this little blurb...

BorgWarner 4485 transfer case, which was developed with GM Powertrain for uplevel, full-size trucks. This transfer case features an open planetary differential. Traction control and wheel slip monitoring are performed by the stability and anti-lock braking systems.

Wide Open

I think that about sums it up.
I have a lot of push in the snow when driving smoothly also. When I apply more gas the front end jerks like it just got power routed to the front.
Do you seem to have even less front wheel power in reverse than forward? I seem to have very little reverse power at the front wheels. If I bring the parking brake on some it seems to send more power to the front. I am not at all impressed with this case for any type of slippery condition driving. On dry pavement I can just spin all four tires when launching and then again when second gear hits. Other than that the t-case sucks.