then put it on even with placing a screwdriver on the mounting plate to make it tight against the belt it would expand to much once i removed the retaining screw. So after it expanded I would get 5 to almost 6mm of gap so I went under the 4mm and once it fully extended and worked its way out it was 4mm. Turned the crank a few times and it was fine. Shit I even ran the car for a few until i realized i had a oil pan leak and pulled the whole motor again. Went and measured the gap AGAIN to make sure it was cool and it was perfect.
Maybe im a special case but that is what I found out worked for me to get the gap EXACTLY at 4mm and not over a mm or more