my 89 s10 blazer is having a little 4x4 problems. it trys to engage the front axles but will not, makes grinding noises but no 4 wheel dig. please help me figure out the problems. thanks

 

Sounds like the typical front axle engagement issue...

There are three things that it could be.

A problem with:

• The front axle engagement vacuum system including, but not limited to:
  • A faulty vacuum line from the engine to the vacuum reservoir.
  • A faulty vacuum line from the engine vacuum system to the transfer case vacuum switch.
  • A faulty vacuum line from the vacuum switch to the vacuum actuator.
  • A faulty vacuum actuator.
• The front axle engagement cable from the vacuum actuator to the front axle.
• The front axle engagement collar/shift fork inside the front axle.

 

i am not sure what you call grinding. but my front diff made a clicking noise (like a playing card in bike spokes) under agressive 4wheeling and front tires stoped working. i was told i was losing vacume. so i bypassed vacume and pull cable manually and never had the problem since.

 

my truck is actually a s10 tahoe according to the glove box badge. but i think it is not vacum opperated its electric. my 4 wheel drive is a stick on the floor.

 

All s-series front axle engagement is done with vacuum.