Chevrolet Repair: 4 wheel drive, 97 Blazer, thrust washers, axle shaft

Question
Hi, Todd;  
    During a recent snow, I pushed the 4 wheel high and it felt like it shifted and the 4 wheel high light came on but it doesn't go into 4 wheel drive.  I then stopped, put it into neutral and tried 4 wheel low.  I heard it shift and the light came on but again no four wheel drive.  I used four drice about 2 months ago and it worked fine. What is the most likely problem and is it a home job?  I just sold my 87 blazer with 210 thousand miles and never had a problem with rhe Four wheel drive but it was manual shift.  Thakk you for your time and knowledge.   Larry

Answer
ok. first i would make sure the encoder is working. it sounds like it is, so just check and make sure. if the encoder is shifting, but no 4 wheel drive, make sure the front drive axle shaft is spinning. if it is, you have a problem with the front differential not locking up. at that point, its either the actuator not doing its job, or the intermediate gears are not locking up. pull the actuator out and push the 4 wheel drive button and make sure the actuator is working. if it is, you are probably going to have to replace the thrust washers, and the washers that separate the intermediate gears. a lot of times, that washer flattens out and it wont let the drive engage. if you are having trouble understanding what i am talking about, print this out, and get yourself a chiltons guide. that should give you good pics and use the same terms, making it easy for you to see what im saying. and to answer your second question, as long as you understand what im saying here, yes it can be a home job. any more questions, please ask, and ill try to be as clear as i can.