Chosen Solution
I have a 1992 Toyota pickup SR5 with the 3.0 engine and the 4 wheel drive does not engage when I go to manually put it into 4-low or 4-high. It DOES NOT have manual hubs so as far as I know it uses vacuum to lock the front hubs in. Is there any fix on to be able to use the 4-wheel drive?
@yota92pickup I believe they call this the ADD (Automatic differential Disconnect). Start by looking through this great write up. For more insight check on here. Now if you want to check your ADD out, here is the part of the SM that deals with it. Toyota ADD Control Hope this helps to get you back off the road:-)