a few days ago my service 4wd light came on, on my 1999 Blazer with Auto 4 wheel..

after reading the forums I cleaned the contacts on the switch, removed the TCCM cleaned all the contacts so that everything engages I can hear it click even 4 wheel low on grass..

but the light comes back on..

then I noticed I drove down the street in 4WH about 20mph with the drivers door open a bit and all I could hear was this loud chain rattling noise and sounds like something coming apart in the transfer case area, (like a chain slapping very hard)

is it time for a new transfer case??

thanks

 

I tried a different TCCM, it's changing into the different modes, but now I'm stuck I dunno what it is, whether it's a front U joint or the transfer case, but it sounds like something's coming apart and gets louder the faster you go..

any help would be appreciated..

 

Transfer case full of oil????

 

Sounds like your TCase lost its fluid and dried out. Which causes your chain in your TCase to get hot and stretch. Then it slaps the side walls of the TCase. Solution new TCase and seal between the TCase and the Tranny.