Hi,---- The answer to your question is NO. I have owned a 91 & presently a 95 w124 that I have done differential service on. The fill & drain plugs are tapered pipe thread which do not require a sealing washer. They are 14 MM HEX size. You will need a 1/2" drive hex 14MM & a breaker bar to "crack them loose", sometimes they "are in there". Make sure you remove the fill plug FIRST, if you drain it & can't remove the fill plug, you have a " Big Problem ". Good Luck ,------ Ray