Chevrolet Repair: chevy s 10 4x4, clutch gear, vacuum switch

Question
Hi Mark i have a 2002 chevy s10 it seems that when i am driving my 4 wheel dr wants to go in gear and this makes a loud humming noise and then i push the 4 wheel dr button and it goes in to 4 wheel and the noise stops so i put it back into 2 wheel dr and it is ok for sometime. then it happens again and so on. i had it at the dealer and they said i needed a new transfercase because the trans fluid was going into the transfercase and damaging the switch but that was over a year ago and i have no leaking or trans fluid loss every thing seems to work ok.except for the above problem. thanks mike

Answer
Hello Mike, This  problem is the vacuum switch on the transfer case. You need to replace this switch. Other damage that could have happened is the shift sleeve inside the front diff. assembly. There is a shift sleeve and a gear that connect the front axle together, this part is the humming noise your hearing. The switch on the transfer case is only appling a small amount of vacuum to the front diff actuator and the two gears are not being shifted, just touching and grinding the teeth off.

        Parts needed

    Transfer case switch
    Front axle shift sleeve (clutch sleeve)
    Front axle clutch gear

Labor to do the job should be no more then 3 hours

Hope this helps

Have a Nice Day             Mark