I am looking at a 2012 suburban LT 4wd, texas edition with heavy duty cooling and 3.42 rear axle. Manual shows 2 speed with dash dial showing 2H, auto, 4L, 4L, and N (5 possible selections) and single speed with 2H, auto, and 4H (three selections}. Actual dash has a dial with 4 selections, 2H, 4H, Auto, and 4L, (no N) Spec sheets are confusing, one shows two speed with "heavy trailer package" but vehicle has components of that package with the Texas edition and cooling as will as a brake controler. Does anyone know specifically how to determine one or two speed transfer case?

 

1 speed tcase are for AWD vehicles. 2speed tcase are for part time 4wd systems. 2speed have high range (2H, 4H, auto) and a low range (2L).

If you buy from a dealer, have the service dept print out an Regular production option (rpo) build sheet using the vin for the vehicle. It will show you all the options the vehicle was built with.

 

got my answer - the manual is somewhat misleading, The N is actually invisible until one actually moves the dial?? Also the 2 speed tcase comes with the heavy duty towing package. But this option is not on the invoice but the components are part of other options. Short story . . . . the one I am looking at has the 2 sp tcase. Important if one wants to tow the vehicle 4 wheels down.