I replaced my transmission with a used one at the beginning of the summer and it came with a transfer case so I switched it along with the tranny. Well I hooked it up and everything has worked fine until I went to use the 4 wheel drive when snow hit, I have the 4 buttons(2, 4 hi, 4 low, and 4 auto), I hit 4 hi and the light flashed but no 4x4. I checked the fluid in the transfer case and there isn't any, it must have been drained when it was taken off and dumb me didn't check it when I stuck it in with the tranny. My question is would running it in 2 wheel drive all summer still have fried the transfer case or should I have hope that the transfer case is fine and there is something else?

 

I think it will only be luck if it's been ran that long with no oil. Maybe there was just enough oil, but I think you'll need to pull it apart to asses the damage. Or, throw some oil in and hope for the best.

 

That's what I thought, I just didn't know if because I was just in 2 wheel drive maybe it didn't engage anything and it'd be fine.

 

Ibhope you put Autotrac oil in it....only from a GM dealer.....also is it working...its been a few
Days

 

I did use autotrac fluid from the dealership. I still don't have 4 wheel drive, I guess I am just going to have to change the transfer case. Good thing I kept the old one which I know was working good when I got the one with the tranny.

 

I cant see how the case would have survived running on no fluid... Even in 2wd the main shaft is still spinning the front input and rear output bearings, along with various freewheeling shift forks/collars that require lube.

That being said, before you switch cases have you verified that the case is actually the problem? Always a possibility that you have a vacuum switch/front axle engagement issue...

 

How would I check those?

 

Just an update, my 4 wheel drive started working, I jacked it up to check it out and it kicked right in, lowered the Blazer back down on the ground and it was still working. I have been using with all the snow we have had lately in Indiana and it is working fine. Thanks for the help everyone!