guys I have a 2000 chevy blazer ls 3 button 4wd system...I push the button for 4hi or 4 lo light comes on sounds like everythin is engaging the cable that comes from under the battery pulls for,the front end ...but there is nothing going to the front tires I have crawled under it and in 2 wheel the axle that's goes to the front turns by hand then when I put it in 4hi or 4lo and,put it in park I cant turn the front axle by hand...and it does turn while vehicle is moving. In 4hi or 4lo but still nothing...I'm at a loss don't know what else to do

 

I am having the same problem with my 2002 Chevy LS s10 zr2. Have you found a resolution? If not, on my s10, In 2hi the front axle doesn't spin. In 4hi and 4lo it does spin. The cable your talking about under the battery goes to an actuator pump and as long as the drive shaft is engaging the actuator is good. I hear that it could be the hubs in the front dif or you might have to just get a new front axle/dif.

 

4x4 Front Differential Operation Explained & Grinding from Front End - S-10 Forum