All,

Is there a difference in the transfer case between an '05 3.0 AWD and an '08 3.0 AWD? The '05 has a coin slot where the '08 has a traction control button. Also, the '05 is a wagon and the '08 is a sedan.

Thanks,
John

 

The transfer case change (no more viscous coupling) occurred in about 2004, so the two you mention should have the same kind of transfer case. The '05 might thus have issues in slippery weather, as it has neither the viscous coupling nor traction control.

 

if you want any type of awd with this car you either have to buy the xcase with the viscous coupling (all xtypes before 2004) or you have to buy one after 2004 with traction control. If you buy a post 04 xtype without traction control, the traction will be far from awd. Personally, I bought an 02 with traction control so I can get the extra traction from the stability control and the viscous coupling

 

The front and rear differentials are both apparently "open", while in the later cars the centre differential (in the transfer case) is open as well. Basically, an open differential can allow just one of the two outputs or "paths" to steal all the power. On a later car without DSC, power can escape through any single wheel, so if you get wheelspin in just one corner you won't be going anywhere. That setup is actually worse than 2WD, because you have 4 traction-critical wheels instead of 2.

On the earlier cars, the viscous coupling keeps the rotation speed of the front and rear end the same, but as there are still open differentials at front and rear, getting one front and one rear wheel spinning without traction simultaneously can still get you stuck.

Having the DSC in the car, however, fixes the issues as it applies ABS to wheels that have lost traction to slow them down. If you compare a VC-only car to a DSC-only car, the VC-only car has superior AWD driving characteristics. However, VC + DSC like disguay has is the ultimate setup.