I plug the through tunnel with 34mm block freezeplugs and pack the cavity with marine grease and then it will even pack the new brg when you put it in, Nyroc has the poop on this he recorded what I posted and others so double check, I kind of forget on the size exactly of the plug but that also keeps the fragments out of the tunnel next time around ....if you yank the input shaft out of the rear end the brg rollers can get in the rear diff ...you dont want that ,so go to nyrocs site for more details and the guys on here are right its not a bad deal at all and we all will have to do this one time or another..jh