When I put it in 4wd it go in ok but it sounds like its working hard or making a winding sound. When I try to take it out of 4wd I push the 2wd button and it does not come out smoothly it makes a very loud CLUNK sound and you can feel it jerk the vehicle. If I stop and go in reverse it comes out usually. What concerns me is the winding sound when it is in 4wd. Can someone help??? Thanks

Check the condition of your tires, specifically tread measurements of each tire. One tire on the vehicle with more tread than the rest can cause this problem. Three of my tires were 6-7MM, but one was replaced due to a blowout. The new tire was 13mm. I told the dealer they were blowing smoke but I replaced the other three as they were getting close. Problem disappeared with the new tires. If you are unsure, strike a chalk mark at the top sidewall of each tire and roll the truck straight ahead 100 yards or so. Get out and see if all the chalk marks line up. If not, the diameters of the tires are different. Even a few mm can cause a problem.

When I put it in 4wd it go in ok but it sounds like its working hard or making a winding sound. When I try to take it out of 4wd I push the 2wd button and it does not come out smoothly it makes a very loud CLUNK sound and you can feel it jerk the vehicle. If I stop and go in reverse it comes out usually. What concerns me is the winding sound when it is in 4wd. Can someone help??? Thanks

Are you changing to 2wd when accelerating?

I have a 1998 Blazer with the exact same problem. When shifting from 4wd to 2wd it sounds like it is working hard and after about 10 to 20 seconds I hear a loud Clunk (like you hit a pothole) and then it is all OK. Interesting is the fact that this started happening about the time that I had my two rear tires replaced. I have had it in the garage twice and they have not fixed the problem. I will have to ask them about the tire issue.

Are you rear tires the same size as you front?

I have a 1998 Blazer with the exact same problem. When shifting from 4wd to 2wd it sounds like it is working hard and after about 10 to 20 seconds I hear a loud Clunk (like you hit a pothole) and then it is all OK. Interesting is the fact that this started happening about the time that I had my two rear tires replaced. I have had it in the garage twice and they have not fixed the problem. I will have to ask them about the tire issue.

4WD vehicles should be replaced in sets of four not two. Something to be said for tire rotation. Since I had the problem I religiously rotate them every 10k.

Very true, the different in tire diameters is probably putting extra pressure on the transfer case.

I have an issue with my 4WD that just started last night. I was coming home from work, took me 2.5 hours for a 38 mile drive. Anyway, got to a light, shifted to park. When I pressed the 4WD hi button, both the 4wd hi and 4wd lo just flashed for a period of time and then reverted back to 2wd. Never went into 4wd at all. If anyone has any suggestions, please email at j.balaja@comcast.net.

Thank you,
Jim Balaja