Hey folks! New to the forum! I have recently came across a problem with my 4x4 system in a 2005 blazer, it seems like it is only half engaging and creating a horrible clunking in the front axle! I have checked the u joints, changed the transfer case vacuum switch. I have the three button electronic switch and that lights up fine! I put the truck on a lift and it does spin in 4x4 but under load or turning it sounds like the gears are not meshing properly! I have a feeling the actuator on the front diff may be getting stuck! Can anyone tell me if this is common or sound like the right route to take?Also when in 2wd the front drive shaft will not spin freely, but when i remove the 3 vacuum lines from the transfer case it will move freely! Thanks for you help.

 

i got the same problem on my dads 97 im still trying to diagnose it

let me know if you find any thing out

 

all tires same size?

 

on my dads pickup there all the same size

 

I thought the noise was coming from the front diff only half engaging but then i put it on the ramp tonight and found it was the transfer case making the clunking! looks like I will need a new one!

 

yea thats where mines coming from also