I don't think Toyota ever had a front locker for the clamshell diffs? Are you referring to the ADD system, it disconnects the right/passenger side axle shaft when in 2WD so the front driveshaft and ring-n-pinion gears don't turn, just the CV shafts and the spider gears in the open diff.
I'm not sure all the 4Runners had ADD, and certainly some Tacoma models didn't. If you had it, and remove it, the 4WD ECU will complain because it uses that to indicate that 4WD is actually engaged. If you didn't have it, nothing to worry about.
I'm not sure all the 4Runners had ADD, and certainly some Tacoma models didn't. If you had it, and remove it, the 4WD ECU will complain because it uses that to indicate that 4WD is actually engaged. If you didn't have it, nothing to worry about.