So I went out this past weekend for a shake down run and found out that my 4lo does not work. It seems like it engages but the rear wheels just dig into the gravel. I tried putting it in reverse and no luck. Its a manual 88 4runner with a 3vze. I looked all over and couldnt find any answers. Does anybody have an idea what the problem could be? Could it be a possibility that the vacuum lines are mixed up?