4 Wheel Drive/SUVs: S-10 Blazer 4X4 1989, vacuum unit, auto parts stores

Question
What goes on inside the front diff. when the vacume acc. is engaged? My diaphrame is brokken open and I tried to engage manually and lock a vise grip on the cable to keep it engaged but It just wont happen.  RAY

Answer
Ray,

I'm not familiar with the system used in the Blazer. On the Jeep's, this diaphram operates a shift fork that engages a two piece axle.  With this unit, you can remove the vacuum hose, plug it off.  Then you can remove the fork cover and assembly, shift the locking unit in place.  Then you simply replace the cover making sure that you place the shifting fork onto the bushing that locks the axles in place.

In your case, I would purchase a repair manual ($20 at most auto parts stores), and see how your system works.  From there you can decide how to lock and unlock your front end manually.

I replaced the vacuum unit on my Jeep with a manually operated cable assembly.

Carl