What all does the LT package option include? Does it include a limited slip differential?

I'd suggest taking the VIN to a dealer and asking for a VIN report. The limited slip differential is something that can be optioned exclusive of trim package. The LT package is a higher end trim package but the Ltd. slip diff may or may not be in it.

GM doesn't have limited slip, they have a true locking rear differential, and that has nothing to do with ls or lt pkg.- it can be ordered a la carte, and to tell if you have it, look in your glovebox on the parts sticker (white or silver sticker, black on top with a bunch of 3 digit codes- the codes are in alphabetical order, and G80 is the code for locking rear diff.- GT4 is 3.73 rear, GU6 is 3.42 rear, GT5 would be 4.10 rear

In 2004, the LT would have been leather, power seats, dual temp, and a bunch of little stuff- LS would have been the cloth pkg. In recent years, the LT is the cloth and the LTZ is now the leather pkg.

Richard. I have a 2010 GMC rear wheel drive with the G80 code. Question. How do I engage the locking rear differential? I have option auto or manual transmission

@Frankkkkkkkk, it locks itself when one of the rear wheels losses traction. https://www.youtube.com/watch?v=MCxqUJCZGNU

Thanks Brent, I was told to engage the positrack I need to shift to manual and put in second gear.