We got our first significant snow in western Pa and I put my Blazer in 4 wheel drive and it worked fine but when I shift back to 2 wheel drive it does not kick-in until driving quite a distance and then it makes a very loud clunk which does not sound very healthy for the transfer case. I tried stopping and putting transmisson in reverse to disengage 4 wheel drive but that does not work either. Any suggestions would be greatly appreciated. Thanks.

 

All 4 tires must be the same size, same brand is better, and equal tire pressure in all 4.
Check the transfer case vacuum lines and filter for restriction. Oil in lines, kinks, etc will cause slow engagement and or disengagement of the front axle clutch.

 

I appreciate your advice. I will first check air pressure in tires as they have not been checked for awhile. Only drive mostly when we get snow. I will get my mechanic to check the vacuum lines and filter when i get the vehicle inspected next month. I used to do a lot of my own mechanical work but am restricted with MS now. Thanks again for your help.
Dave