Hi, with this Blazer being my 1st ever 4wd vehicleI am not experienced with exactly how everything should "feel" when in 4wd. I tried all the buttons (Auto 4wd, 4hi, 4lo & 2hi when I first got the vehicle just to make sure everything worked - and it did. All the lights come on as they should - even tried the neutral setting & that works OK.
There is a definite difference in the steering when switching between 2hi & 4hi which is what I would expect with the extra torque through the front driveshafts. The steering is much lighter in 2hi - I assume this is right? Yesterday I had used the vehicle in 4hi because it was icy & forgot to put it back into 2hi before I parked up. Today when I started out I had to steer onto full lock to get past another car that had parked up close & the vehicle was very reluctant to move, almost like when brakes are binding. I put it back into 2hi & everything freed up - is this a cause for concern? Does the front axle have a diff lock becaue that's what it felt like? I have never noticed this before but it could be that i've nver used full lock in 4hi before? I use 2hi about 99% of the time. I notice it says in the owners manual that using 4hi/4lo excessively on normal paved roads when it isn't slippery can shorten ther life of the drivetrain.
Any advice would be appreciated & I hope I haven't damaged anything?
I also hope this doesn't sound like a stupid question.

 

Perfectly normal operation. It has been explained before on this site and many others. When in intermittent conditions, just use Auto4wd. Lock it in to 4HI when all of the ground is covered, but disengage when doing tight maneuvers.

 

Thank you for that - that puts my mind at rest.
Incidentally, on 2 occasions I have had the "Service 4wd" light come on, even though everything seems to work normally. If I stop the engine then start it again it goes out & stays out for the rest of the journey. Wondered if one of the switches on transfer case or front diff is sticking occasionally & not telling TCCM what position everything is in?
I suppose maybe I shouldn't worry about it as long as everything works. Sounds like some folks on this forum have had major pains with their 4wd systems compared to me so I shouldn't really be complaining I suppose.

 

If you really wanted to know why the 'service 4wd' light was coming on, you would need to have the TCCM scanned by a capable full feature scan tool (GM Tech 2 or equivalent).