2002 chevy suburban push-button 4wd not 4wd on snow.

Ok first, its the transfer case making the noise not the transmission. Second in order to put it in 4 low you have to be completely stopped, put the gear selector into neutral, then push the 4 low button. You should hear a kind of a loud clunk as the transfer case changes gears. It's totally normal and may take a couple of seconds after you push the button.

As far as 4 hi not working, if the truck hasn't been put into 4wd mode at all in a long while the actuators on the front end might be dry or stuck. Have you tried engaging the 4hi while moving forward at all?

Thanks for the response. It's a "new to me" type of vehicle, first 4 wd, so I'm getting used to the ins and outs. I did notice a fairly loud clunck when I shifted into low 4wd using the same procedure as you put up. It did still seem like it was in 2wd in the low setting, too. I have shifted between hi 4wd and 2wd whilst moving forward. Hasn't made a difference that I can tell.

If its in 4 low and you shift the gear selector from neutral back to drive if the 4 low is truly in you will only be able to go about 30-35 mph. The gear reduction is that great in the transfer case.

Yup. The 4wd low mode is intact. I did notice that the back wheels were spinning but not the front wheels in this mode as well.

Sounds like bad front wheel actuators, broken/corroded wires or a bad transfer case. Take it to a REPUTABLE mechanic and have them look it over.

Thanks for the help!

My 2002 Suburban the 4wd works when the auto 4wd button is pushed but the 4hi and 4lo buttons pushed the back wheels will just spin but the front wheels won't spin if i am stuck in the snow so i have to keep it in auto 4 for the 4wd to work.

Hhmmmm I would start with replacing the switch in the dash. Do the 4hi n 4lo lights stay on when they are pushed or do they blink and go out? When selecting 4lo the gear selector(gear shifter) has to be in neutral first. Let me know.

I just replaced the switch on the dash and it's still doing the same thing only working in auto 4. I also make sure the transmission is in neutral

When shifting to 4lo and the lights blink after the button is pushed and then stay on.

Ok then just you'll just have to do the same thing as I stated above in the original post. Get it looked at by a REPUTABLE mechanic.

Mine is doing the same thing. I have replaced the switch and the front axle actuator and it still only works in auto 4 not 4hi or 4lo. I am at a lost. I can hear the transfer case shifting. I guess I will need to take it to a mechanic so they can put a scan tool on it and look to see when it's shifting to 4 hi or 4lo what the computer is reading of what is happening.

Make sure the transmission is in neutral, make sure your on level ground ,, also there's a sensor on the case look under check for loose or broken wires or change sensor

The first thing to check is your front axle actuator, It simply screws out of the right side front axle housing . when removed you can hook the small plug back up , have a friend to engage the 4wd , You will be able to watch the (plastic piston) extend outward to push the slide pin that locks the two axle gears together, If this actuator is working put it on jack stands, with trans in neutral, You can repair this without a diagnostic scanner, Also you can actually take your finger and push the slide pin located in front axle, of course with out the truck running of course., you can actually feel the pin push in and lock front axles together, at this time when you turn your axles you will see front drive shaft turn , Most people always want to buy the cheaper version of this actuator, I have changed hundreds of these over the years and WILL NOT USE AFTER MARKET ACTUATORS, They will never work properly, if they do , they will not last. . You can simply get a free scan at Oriellys, auto zone and some napa dealers, But do not listen to these guys , Most just want to sell parts and if they knew so much they would n ot be selling parts for $8- $10 per hour , they would be making a lot more installing them .. But it might get you on the right track if you will right down the codes and do your own research after doing the manual diagnostics. If your switch on the dash is operating the the transfer switch its not bad. I have only replaced I 4wd module in a chevy in over 20 years , so don't get side tracked with that ..................... A cheap front axle actuator is the problem most of the time if you don't have inside(hard parts ) damage in your front housing assembly ..

A don't bag on your parts guy a good won will make 25 to 30 and be able to tell you what's going on he talks to 50 of those techs a day so I'm glad he's so smart but before you buy anything troubleshoot it first instead of buying anything check voltage to the switch it should be in a certain range fuses relays and wiring as well that's a start the Creech

I know this thread is a bit old, but I am also having this issue of 4 high and 4 low not working, but auto is. Another weird thing is that it only has this problem when the car is left in temperatures below freezing, it works fine if the car is is warm weather. Any ideas on what the problem is?

Sam the solution for me ended up being a whole new actuator on the transfer case that shifts it from 4LO to 4hi, it had gotten weak over the years and didn’t have enough force to shift it in 4hi or 4 Lo, had a shop replace it and that did the trick