like the topic says, my 97 jimmy does not go to 4hi when i press the 4hi button, 4hi will blink few times then the 4lo light comes on and stays on(without being pressed) then i hear a loud clunk which i assume the 4wd system engaging. and then it's very tricky to go back to 2hi, i have to throw it in reverse and then forward about 20 times to go back to 2hi.

 

Sounds like the classic encoder motor faulting out. You could get lucky and find corroded wiring at either the encoder motor (side of the transfer case), the TCCM (behind passenger side kick panel), or the switch in the dash. You could also test the switch to make sure that it is working properly.

Check out the Tech Article (DIY) section for information on the NV233 transfer case. error_401 wrote a good article a while back based on his 94, but it had the same transfer case so it sill applies.

 

thanks for the quick reply. i tried taking off the encoder motor, have the three bolts removed and have been trying to wiggle it out for days now, there just seems to be not enough space to do it and i don't wanna have to remove the front output shaft flange(i think). or if i do remove it, will i mess up a bearing seal or something of the sort?