I'm BRAND NEW at the truck thing, but i bought a 4x4 blazer FOR winter. today i got home and stuck in yard in very little snow. I put 4x4 hi, and tried lo and tires JUST spin. Any ideas? THIS is the reason i even bought it was for winter snow etc. the lights on the 4x4 hi and low button come on and stay on but worthless!!!

 

what kind of tires do you have?

 

i dont know, never looked but plenty of tread. I didn't know if this meant the 4x4 wasn't working or what.

 

Do either of your front tires spin as well as the rear? If neither front tire spins with the rear tires then the truck isn't locking in. Don't try and spin the tires at high speed either, especially when just changing to 4x4. If you're stuck you shouldn't let your tires spin at all for several seconds after pressing the button, and normally the truck has to roll a few inches forward or back for the front differential to fully lock in. There's also several things that can happen with the 4x4 system where it will appear to be working but won't spin the front. The most common is a vaccuum problem with the front diff actuator under the battery tray.

 

ok thanks. this evening i'll shovel and salt around it and get it straightened out and maybe this weekend take it somewhere to make sure the 4x4 etc DOES really work. if i have to move a bit to get 4x4 IN, i guess in winter i'd have to drive nonstop in 4x4 just in case this happens again!!!

 

Just be sure you're not driving on dry roads in 4x4. You will break things if you do this. The best practice if you're going from a dry road to snowy roads is to push the button once you get onto the snow, while you're still moving. This will give the truck the second or so it takes to lock the diff in, before you're already stopped and stuck.

 

have you had someone else look to see if either of the front wheels are moving when the 4wd is engaged? turn on the truck, put it in drive, push the 4hi button, and hit the gas,and have someone see if either of the front tires are spinning with the rear, like has already been said. If not, then your 4wd is not engaging...

That being said, NEVER try to engage 4lo in anything but neutral.
4hi you can do on the fly, while the truck is moving. ive changed into 4hi at speeds all the way up to 35-40mph and it engaged perfect.

 

ok, that is interesting, i was told 4hi was the same as low as far as cant switch until stopped. HMMM that would be much easier to switch while driving!!! Still got to be in neutral or can i just hit the 4hi button?

 

4hi does not need to be in neutral. It's shift on the fly.

 

When doing a mode shift, (2HI to 4HI or 4HI to 2HI) it's best to be moving, just take your foot off the gas when shifting. If the system is working properly, you can do a mode shift at any speed.

Vehicle must be stopped to do a range shift, (4HI to 4LO or 4LO to 4HI).