divingduckman

The 4wd in my blazer won't shift out of 4hi. I push the button to go into 2hi and the light flashes and I hear a couple of clicks from the transfer case. It shifts from 4hi to 4lo fine but going back into 2hi does not work. I've already replaced the transfer case switch but it still does it. This has happened before and I had to go forward and backwards while pushing the button to get it back in to 2hi.
THANKS FOR ANY HELP

97 chevy blazer 4.3 v6 4wd

Loe39

try rolling in N

loots-42

I've got this same problem. It doesn't want to come out of 4WD. Shifts fine between 4HI and 4LO, but doesn't want to go to 2WD. I read a post on another board about checking a little ball on the transfer case vacuum switch that may be stuck.

Does anyone have any details on what that suggestion might be about? Thansk

loots-42

ttt - help please!

OverBoardProject

Look on this web site, for a troubleshooting guide.
http://www.4x4posi-lok.com/PDFs/TSG_chevyT.pdf
I don't know if they'll have what your looking for or not.

loots-42

I've found that the only way mine shifts out of 4WD is if I'm going slowly and turning sharply.

What could that mean?

NOVA71

Yes there is a vaccuum switch on the transfer case. Try removing it. Inside it is a check valve (little ball like a small ball bearing). Often this sticks and will not allow the diff back into 2wd. You can try soaking it in WD40 and push on the ball to work it free. Keep working it until it pushes in and out freely. Then reinstall it in the transfer case. Hopefully this will fix your prob.

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newly75

if you can hear the motor try to disengage from 4WD but it still stays in 4WD, try this. Get out and under the truck, with a flash light, look at the shift motor, on the side of the housing containing all the gearing for the shifting, there is a plastic section, where the wiring harness for the motor plugs into ( at the top above the front drive shaft) Take a close look at the plastic section that is on the side, does it look like it is bowed, and starting to pull away from rest of the housing between the screws that secure it to the housing? If it does, it means that the sensor that turns with the shaft that tells the comp. that is has gone out of 4WD, is not turning, and it will try two more times to get a proper shift, if after that it doesn't get a 2WD postion on that sensor, it defaults it back into 4WD and aleaves it there.

The solution is to replace the motor with one fropm the junk yard. the whole unit is not really meant to be opened and / or serviced. but.... if you think you can handle it , and have the patience to take your time. you can remove the motor assemble from the TC , and try to remove the platice section of the housing and clean the crap out from between them to try to get it to seat flat again so the sensor will reach far enough into the shaft to be turned, to give the 2WD position on the sensor.

Hope this helps

blazes9395

If your light is flashing at the transfer switch, then it will not have anything to do with the vaccuum lines, or the vaccuum switch on the transfer case. Newly75(welcome by the way) has the right idea, it usually has something to do with the electronics, the encoder motor, the switch(you said you replaced it anyways), or the wiring in this system. You can try discconting the negative battery cable and resetting it and see what happens.