My Dana 30 Front axle on my 89 Wrangler comes disconnected when I blip the throttle on four wheel drive, High or Low. I have a feeling it has something to do with the vacuum canister on the passenger side of the engine bay, but I'm not sure. Seems that way because when you blip the throttle quickly, the vacuum goes down and would allow the axle to disconnect if it wasn't working properly. Anyone have any input?
Could be that your vacuum canister is bad. It should hold vacuum to prevent that from happening. Check that and all the lines going to and from it for cracks or leaks. A good upgrade is to go with one of the number of cable accuated setups. Yes, it's pricier but I think it well worth it for the added reliability.
First, are you sure that your axle is even engaging? Jack up the passenger front wheel to see. It shouldn't be disengaging unless there is either positive pressure through the vacuum line or vacuum is being applied to the opposite side of the vacuum diaphram. Even if the vacuum is low or drops for a second, it should still be engaged.
I am sure it connects, and it will stay engaged as long as I ease into the throttle very slowly. As soon as I mash the pedal, though, it disconnects. I'll look into the cable device. Any other info will be appreciated