Having trouble with shifting from 2HI to 4HI.Ive runnout and checked,most vacuum lines,actuator under battery,no problems with wiring routes or damaged wiring.I havent checked TCCM and its terminals or plugin,plugin and switch on T-CASE,and vacuum lines hookup behind distributor.When in 2HI,I push selection switch 4HI on the fly,and the tranny neutals out,there is no noise,nothing.When sitting still,Im in 2HI,I push selection switch to 4HI,tranny in neutral,selection switch flashes like its changing to 4hi,wait till it stops,put tranny into gear,tranny is in neutral,nothing???I get out to check the front driveshaft,it is free and not engaged,so to drive the truck it has to be selected back to 2HI.I do have 4LO and it goes in and out. and works fine.This truck is cherry and been kept very good care of,it has had the tranny rebuilt about 4 years ago,and works great!t has a 233C T-CASE. Is this a common problem with this truck? ANY TECH HELP OR ADVICE WOULD BE GREATLY APPRECIATED!!!!! RobD owner of S10'S for 11 years and counting!!!!!

 

I think the transfer case is neutraling out, not the trans...... with that said have you checked https://blazerforum.com/forum/tech-a...2hi-4hi-40695/ to see if it's your encoder motor by chance?

 

no I havent,and I appreciate your imput!

 

You're welcome. Post back after diagnosing and let us know what you find/don't find.

 

Thanks,Ill Do.