02 s10 Blazer 4x4 VS beach sand
 

So on Saturday I decided I'd take my lady out to the beach to cruise along the coast.. Welll my 2002 S10 blazer 4x4 wasn't happy needless to say I got stuck, couldn't go more than 12mph, seems like the Trans wouldn't shift? I was in 4hi and on packed sand, my tires weren't more than an inch deep but my SUV just wouldn't go. So I tried 4lo and same result. No matter how much gas I gave it, it just revved up and at one point in 4hi it shuttered bad. Put in back in 2wd and it actually made it better through it all. Not sure what it was but it kinda rained on my Saturday out. On my way back out to the road I ended up stuck and got help from an old man in a Jeep saying "it's a jeep thing, you wouldn't understand". Lol any ideas on why I couldn't go faster with out revving to nearly 5k RPM?

Sounds like the front axle isn't locking. Are the tires spinning? Is the 4x4 switch blinking, or an ABS light on indicating a wheel speed sensor issue?

I would check the vacuum actuator under the battery tray. Start it up, put it in 4Low and make sure you see that it's pulling the cable to lock the front axle.

I got stuck once in some real minor loose dirt. What happened is my front axle had become disconnected. I'm in the middle of a posi-lock setup, but haven't completed it. Once I figured out neither of the front wheels were spinning, I was able to fix it and get out. Like Travis said, check the actuator.

Also, airing down the tires on sand can make a HUGE difference. Airing back up once you're on pavement can be another problem, though.

I'll check those things today. The 4wd would blink for a sec but then stay solid. It almost felt like I didn't have it in drive all the way but I had checked that and it was. I'm a service writer at a dealership so I'll talk to the mechanics about today too. I'll post back

Btw I do have the intermittent ABS light issue that comes on occasionally when I start up some days.