I have a problem with the front diff trying to drop into 4WD causing intermittent resistance in the drivetrain and clunking while I am still shifted in 2WD. This is accompanied by a chattering from under the dash. Seems the ADD relay is rapidly closing and opening. Not sure if it's the relay going bad, a wiring problem, or if the shifter switch is misaligned.

I currently have the front diff forced into 2WD by moving unlock vacuum line to the 4WD vacuum service valve and leaving the lock line blocked. Anyone seen or heard of this before? Any help would be appreciated.

 

never heard of anything like this before....

maybe its a good excuse to convert to a NON-ADD front-end... I know I adventually want to have a NON-ADD set-up up front.

 

You mean replace the diff and get manual hubs? I like the (lazy) ease of shifting from the inside (like when I don't want to back into snarled traffic in the bank parking lot and just go over the curb). I want to keep the 4Runner running proper, but all my big upgrade funds are going into my 87 Supra. Thanx for your reply.