I have a 1998 S-10 blazer and I'm having a problem here and honestly I have no clue what it is to sum up my problem I'll give a few stories of what is happening and hopefully someone can sum this up for me. Okay I went with my dad to his girlfriend who lives in Kentucky (which there is jack to do there) and they had a huge field that looked to me as a 4x4 place hills etc so I go through it no problem in 2wd find this big hole and stop in it and put my car into neutral and pushed the button into 4low and I could here the transfer case kick in but no turning of the front wheels at all so, I put it back into neutral and put in 4hi still same thing after finally getting out I was puzzled so to my next story this happens about last week I thought I figured out how to get the 4hi/lo to lock by putting it in neutral then rev and it would jerk and then put it into drive soon to find out I took it out 4 wheeling and had the same problem only the rear wheels spinning. What could this be I mean I hear my transfer case locking and the rear going into lo but not the front? My friend tells me it could be the transfer case motor going out if so why is it locking the rear wheels. Sorry about the long story trying to get that out there about my problem and hopefully get some help. Thanks a bunch, Mark.

 

I some years ago had a solenoid that was sticking and the front wheels were always engaged. Even if I hit the different 4lo and 2lo etc it sounded like it was kicking in and out but was not. I think it was located in front transfer case area. Hope it helps.

 

If there is a physical gear change when going into 4LO, then the transfer case is working properly. Your front axle is probably not engaging though.

There are many threads on this. You have to start by checking the vacuum actuator under the battery tray for proper operation. It should be supplied with vacuum pressure when the truck is running and in one of the 4wd modes (4HI or 4LO). When it is supplied with vacuum pressure, it should pull on the cable, engaging the front axle.

If you do not mind having to pull a handle, you can fix it once and for all with a posi-lock setup which replaces the vacuum actuator controlled by a vacuum switch in the transfer case with a manual cable. Depending on the type of pull cable you use, there may be further routine maintenance that must be followed with a cable lock system such as this. If the cable is unprotected (ie. bare metal outer sheath), you will need to keep it well lubricated so it does not freeze up due to either corrosion or water intrusion in the winter.

 

Okay, so, I took the bat tray off and started it and did the Lo and Hi and my friend said the vacuum actuator didn't even move. I honestly would like to keep the push button but, I don't want a stomp in my wallet. What should I do about this?

 

had the same problem with my 98 follow the vac line from the pod down to the trans on the driver side of the trans is three vac lines that go into a triangle shaped rubber plug that plugs into the vac switch make sure its plugged in if it is pull it off and look for the alignment hole on it and feel it on the vac switch and plug it, if that is right under there check every vac line you can for leaks. hope that helps

 

http://www.am-autoparts.com/AM/Four-...8/AM-34278924/
http://www.am-autoparts.com/AM/Four-...8/AM-36913506/
Im thinking about changing both of these and the hoses think that would be a good idea?

 

It probably would fix things, but not if the cable is froze up. You need to verify that vacuum is getting to the actuator. You also need to verify that the cable is free to move. If you are not getting vacuum to the actuator, then I would say replace the vacuum switch. If you are, and the cable is free, then I would replace the actuator as it likely has a leak. Replace the hose if you find a leak or just for peace of mind.

 

What you mean by the cable is free to move when I took the bat off I was moving the cable in and out so is that what you mean?

 

Yes, that is what I mean. If you mentioned that already, I must have missed it.

You can also check the actuator with a hand vacuum pump, applying a vacuum to it and seeing if it will pull the cable.

If you have no vacuum to the actuator, I would start with the vacuum switch.

 

Honestly whenever I took the bat off I didn't even see a hose visable. I'm going to take it off again today and see what I can do. I do greatly appreciate the help.