I'm originally from Flint, MI. My father and grandfather both worked for GM. I've owned and driven many GM vehicles, but this is my first Trailblazer.
I have a diff question later in this post for those that want to skip my intro and get right to the meat.
I found a 2003 LS with the 4.2 LL8 with 65K miles recently, owned by a single (old) person and in kept in mint shape. It's pretty much perfect for my daily driver and I'm going to lift it and do some mods to help me get to the trailheads I want to reach here in Colorado. I'm a photographer, and this vehicle will eventually help get me down some roads that my last rig had no chance at managing.
I've always done all the work on my vehicles. (I grew up the son and grandson of GM employees...) I've already done some small tinkering on the Trailblazer: cleaning the throttle body, tightening the intake manifold to fix some rough cold idle issues, replacing the rear calipers as they were wearing unevenly and the brake fluid needed to be changed anyway.
One thing that has surprised me about my Trailblazer is the get-up-and-go. That LL8 kicks out some power ... until I take it up to 12,000 feet in elevation, where it's a total dog. I plan on tinkering with that at some point. (I've driven a lot of vehicles in the mountains here, and my Trailblazer has more loss of power than anything I've driven above 12K. Up to about 10,500ft or so, it's reasonable.)
Now my question:
I don't have the G80 differential option, which I knew at buy time (the deal was too good and meant that adding a mech locker later would still save my wallet in the end). So, my understanding is that I have open diffs front and back. But, when I use 4H or 4L, I could swear that both front and rear diffs are completely (not slip-locked, not mech-locked) locked. Here's what happens in both 4L and 4H when you put the vehicle in gear and turn the wheel as far as possible:
1) On pavement: Move about 5 feet and bind-up happens, stopping the vehicle. I have to hit the gas and break wheels loose to move. It's relatively violent and the front diff moans if I do this on pavement.
2) On our dusty trails: Both front and rear axles independently pop a wheel loose before bind-up happens. So, if I crank the wheel and do a slow circle in a dirt lot, my wheels just go "pop pop pop-pop pop...".
When I transfer out of 4L/4H, this bind-up is entire absent.
What do you make of this? It _feels_ like the diffs are entirely locked... but that isn't an option on this vehicle, from what I've read anyway.
Cheers,
Jason