95 Blazer S10 automatic, purchased used

Is this 4 wheel drive on the fly or do you have to be at a stop?

When I purchased the car the 4w drive did not engage - it was the actuator under the battery case - I replaced it and now have "action" on the gearbox going in and out, but it will not stay engaged.

Any thoughts??

 

4wd on the fly, but you should be careful at higher speeds or if you are already spinning the tires. Do not engage it with any one tire spinning or actually with it under power. If you stick with doing it on the fly with your foot off the gas, then you should be fine.

I can't remember if there is a vacuum solenoid that pulls a vacuum on the actuator or if it is from a selector on the transfer case. Either way, try to follow the vacuum line. It sounds like you are losing the vacuum source after alittle bit.

 

it engages and then pops out, almost as if it doesn't "lock" in all the way