I just bought a 1985 Blazer S-10 that has only 62k original miles on it but has been sitting for quite a few years. The only real problems that I am having with it are that the windsheild wipers don't work and that I can't engage the 4 wheel drive. With the wipers I think it is the switch b/c when I put the wipers on the wiper fluid comes out and the higher I put the wipers on the more the fluid comes out. The problem with the 4 wheel drive is more confusing. when I engage the 4WD high or low you can hear a difference in the gearing but the front wheels do nothing. If I get stuck and put it in 4WD just the back wheels spin. Any suggestions? Thanks.

 

I had an 89 S10 Blazer that had the same 4X4 problem. My had sat for a while before I bought it too. For me it was a vaccuum line. One vaccuum line had a crack in it, you could here it engage but no power to the front wheels. I would check for vaccuum leaks first. You might what to check the hubs out too. If it was sitting they probably need to be lubed.

 

This is my first 4x4 vehicle so I am new to some of this stuff. How do I check the hubs?

 

I found what I think is the actuator on the fender wall on the passanger side and it had two vacumm hoses lying next to it disconnected. I think this may be causing my 4x4 engaging problem. Anyway, I attaced one of the hoses where I thought it should go but the other one I am not sure where it goes. You can see them both in these pictures.


[IMG]local://upfiles/874/E2E87041ABB349D6B6E6A331802D5931.jpg[/IMG]

[IMG]local://upfiles/874/5A9D76A458BF4037AEF0262718E93B7C.jpg[/IMG]

 

What size motor do you have, and is your truck Auto or manual transmission.

 

It's a V-6 with a manual trans.

 

More then likely you fixed the problem, maybe?
Based on the pics the hose you attached goes to the vacuum actuator for the front diff. You have it correct.
The other hose (?) has a filter on it and is a breather hose that goes to your transfer case. It runs up into the engine compartment so that when you drive through water, the water doesn't get sucked into the t-case and destroy it. Both axles should also have breather hoses on them as well. Crawl under the truck and find them, see where they go. I ran my rear diff breather hose all the way up to the engine compartment as well. I also ran a hose from my 700R4 auto tranny to the engine compartment. I take my '87 S10-Blazer 4 wheeling all the time. So having those hoses in the engine compartment helps to keep water and mud from detroying my axles, tranny, and t-case.

I wrote that you might have fixed the problem. The vacuum system is prone to failing for various reasons, so hooking the hose up might have fixed it. Then again it might not and replacing the factory vacuum set up isn't worth the money. There is an easy permanent aftermarket fix. Buy a Pos-Lok kit and install it. http://www.4x4posi-lok.com/app_chevy-s.html
Costs like $100 and eliminates the vacuum system. It works via a mechanical cable you pull from in the cab of the truck. I made a home made version that cost me $30. If you look at the vacuum disconnect (where you attached the hose) it has a cable that runs down to the front diff. All you need to do is install a cable that runs back into the cab of the truck, thus eliminating the vacuum system. That is what I did. My Posi-Lok works different then the kit on the Posi-Lok website. Take a look at mine and theres and you should see the difference.

http://offroadworld.tenmagazines.com...66-album-10757
I addeed info to each picture, however to see it you need to see the picture in fullsize.




The hubs on the s-series trucks a permenately sealed "locked" units, and they do not "lock" or "unlock" like other 4x4 trucks. There is no maintenance to the s-series hubs. The front axle is "locked in" via the vacuum when the t-case is engaged. With the Posi-Lok upgrade you have to engage the t-case and then engage the front axle. This can be done from insdie the cab of the truck. While on other 4x4s the front axle has to be engaged by the hubs, someone has to get out and do it, and that might be in the middle of a puddle or mud hole.

 

Thanks for the info. I checked out all the pics and everything. Here are a few follow up questions:

1) Is it possible before going through and installing a line to first test it by physically pulling on the line where the vacuum is now while the truck is stopped to sort of manually put it in 4x4?

2) Right now the truck has 4x4 high and low. With this direct connection do you still have the high and low?

Thanks.

 

1) Yes, you can manually pull the cable and lock the front axle in. Some just use a pair of vise-grips. They pull the cable out and clamp the vise-grips in place. The cable only travels about 3/4".

2) Yes you still have 4hi and 4lo. 4hi and 4lo are functions of the transfer case, not the front axle.
When you shift the transfer case into 4hi it engages the front driveshaft and rear driveshaft at a 1 to 1 ratio. In other words the t-case will spin the tires the same speed as the transmission does when in 2wdr.

When you shift the transfer case into 4lo it also engages the front and rear driveshafts, plus it reduces the output of the t-case by 2.62. So your front and back axles turn 2.62 revolutions slower then when in 2wdr or 4hi. Not all t-cases have this ratio, ours do.

Here is a website called how stuff works. This link is for how 4wdr system work. They do an excellent job of explaining the basics of 4wdr and how it works. Also have some excellent demonstration videos. Please feel free to ask if you have more questions.
http://auto.howstuffworks.com/four-wheel-drive.htm

 

Some info that will help you as you read the link about.

All S-series trucks have a part time 4wdr system, except for the typhoon and syclones. They are all wheel drive.

Look for the little green "play" buttons in the diagrams. Click on them and they will give you a visual demonstration of the topic.