No 4x4 Front Diff Not Working??

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No 4x4 Front Diff Not Working??

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Blazer Forums >> Mechanical & Maintenance >> General Tech Help >> 1st Gen S-series (1983-1994) Tech >> No 4x4 Front Diff Not Working??

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No 4x4 Front Diff Not Working?? - 12/6/2005 10:48:04 PM

slayer6x6

Posts: 8
Joined: 12/6/2005
Status: offline

Well so far I figured out that the transfer case is working because the front drive shaft spins when its engauged, but the front diff will not lock up. There looks like a solenoid on the front diff, how do I check this? Is the front diff vacuum operated? Any suggestions or info are welcomed. Thanks!!!

BTW, the car is a 1993 Blazer with the pushbutton controls.

Post #: 1

RE: No 4x4 Front Diff Not Working?? - 12/7/2005 1:20:51 AM

Hanr3

Wheels & Tire Moderator
Posts: 3523
Joined: 5/11/2005
Status: offline

More then liekly it is your vacumm system. Could be as simple as a leaking vacuum line. Look for a cable running off the front diff, it should run up under the battery. Take the battery out, take the battery tray out. See the cable? It should be attached to a device that has a vacuum hose attached to it. Pull hte cable out and put a pair of vise grips on it. Put your battery tray and battery back in. Go test to see if your front axle is now working. If so, do yourself a favor and buy a Posi-Lok kit. Costs about $100, but it will permanetly replace the vacuum system with a cable that you pull from inside the cab of the truck. The cable will never fail, unless you fail to pull it out all the way.

If you want to see pics of my home made posi-lok kit on my '87 S10-blazer, post up.

One last thing, make sure your radio theft lock is turned off before you disconnect the battery.

_____________________________

"Some people spend an entire lifetime wondering if they made a difference.
The Marines don't have that problem."
-President Ronald Reagan

'87 S10-Blazer - SOLD
'93 S10-Blazer 4x4x4 - Sons DD, engine swap is done.
'00 S10-Blazer 4x4x4 - My

(in reply to slayer6x6)

Post #: 2

RE: No 4x4 Front Diff Not Working?? - 12/7/2005 6:09:31 PM

slayer6x6

Posts: 8
Joined: 12/6/2005
Status: offline

Thanks man, I found that the diaphram on the vacuum actuator was ripped. I ended up just getting a new one from GM for $70. The old actuator was wet with oil, it appears that it sucked up some transfer case fluid at one time. Does this need to be addressed?

(in reply to slayer6x6)

Post #: 3

RE: No 4x4 Front Diff Not Working?? - 12/8/2005 12:24:24 PM

Hanr3

Wheels & Tire Moderator
Posts: 3523
Joined: 5/11/2005
Status: offline

Not really. There are three hoses attached to the t-case. One is a vent line, one is vacuum supply, and the third runs up to the actuator. If the t-case gets too hot, the fluid travels up the hoses, expands. It should drain back into the t-case as it cools. Make sure the vent line isn't plugged, it should be located next to the actuator and has a funny looking top to it. The top is a filter to keep debris out of the t-case.

The only thing I would do is make sure the t-case has the proper amount of fluid in it. They is a plug (bolt) on the backside about half way up the case. Take it out, stick your little finger in there. If you feel fluid, or a little fluid comes out, your t-case is full. If not, you will have to add some fluid. Should be tranny fluid, but double check. Adding the fluid can be fun.

If you have to jack up the truck to get under it, jack up the back end.

_____________________________

"Some people spend an entire lifetime wondering if they made a difference.
The Marines don't have that problem."
-President Ronald Reagan

'87 S10-Blazer - SOLD
'93 S10-Blazer 4x4x4 - Sons DD, engine swap is done.
'00 S10-Blazer 4x4x4 - My

(in reply to slayer6x6)

Post #: 4