cameronmjohnson

Ive tried searching on here, but I didnt find much. Ive got my eye on a 08 SD but I have some concerns about the AWD system. I dont plan on off roading the SD, but living in Montana I will have to deal with snowpacked roads quite a bit. Ive heard of guys getting stuck in 6in of snow on level ground because it is a 100% torque split to the rear in reverse. Ive also heard that the AWD system on the GMT-800 SDs were alot better because they were viscous coupling vs open center diff in the nnbs trucks. Did they change the system in any newer model year trucks? Just looking for opinions on whether the truck will work good enough so I dont get stuck in my driveway.

1Bear

iTrader: (1)

They did change the system for the GMT-900’s when the 2007 Sierra Denali was released to a system more comparable to what the 2003 and up SUV’s were equipped with. It is an open center differential type that applies power in conjunction with the ABS, whereas the 2001 thru 2007 Classic Sierra Denali’s and 2001 & 2002 SUV versions were equipped with the NVG-149 that was totally mechanical in nature by use of a viscous coupler. Hands down, the earlier style was a more capable performer, but owners of the newer style say they don’t have too much of an issue handling snow and loose sand, especially once they learn the intricacies of owning a vehicle equipped with an open style differential. You end up having to apply the power slowly to allow the ABS to let the system send the power to the wheel(s) with traction, whereas if you just try to get into the throttle, it tends to just screw up the system and you end up spinning one axle. With the earlier trucks you could just nail the throttle and hang on. Not having a truck with the newer system, I’m not one to give advice one way or another as to whether you should or shouldn’t purchase a vehicle with this style of system and really would point you towards DenaliTrucks dot com to see what the owners of the newer trucks have to say about their feelings towards the capabilities of them.

nikon2011

Well I had my 2011 truck threw the most recent brutal new england winter. I give it a thumbs up. (I drove a 04 SS before this so I've had both)

My job doesn't let me miss major snow days, I was driving threw unplowed streets with a 1' + of snow without issue.

My girlfriend took the truck to work twice because her vehicle couldn't make it, she called it a "tank"

For what its worth... Good luck

cameronmjohnson

Thanks for the input, sounds like it will be fine for winter driving. Just to be clear, if Im driving on a snowpacked road at 65mph, the torque split will be roughly 40/60 until it detects slip, then it redirects torque where it is needed?