sounds like the pinion for the diff.. yes you have to take apart the box, shouldn't be hard to fit.. i didn't know the pinion from a l.0box would fit.. was under the impression the boxes were different as the aftermarket jdm lsds that are made for the 1.0 box dun fit into the 1.3 box... gay. can you confirm that the 1.0 crown wheel n pinion will definately bolt up to the 1.3 gear? cause i know where there's a 1.0 box just sitting down the road from me but its not the facelift model jobie