I drained the transmission on my W4 and noticed a plug on the bellhousing just behind the oil filter. I pulled it but it was dry. Anyone have any idea what it is for?
Could it be the timing inspection hole. It will be about 3/8 to 1/2 inch in size. Did you look in the hole while you had the plug out. If it for timing you should be able to see the flywheel rim.