Originally Posted by syfi

Crush washer goes on the drain plug. It's usually replaced whenever you drain the trans. You can usually find the 3 kitted together (filter, pan gasket and crush washer).

Mercedes Transmission Filter Kit - Meyle 1402700098MY | FCP Euro

Quit freakin out. You're only 4000 away from 100,000 which is when you would have originally changed it anyway. Leaving the old fluid in with a dirty filter will do WAY more damage then if you renew now, like M/B intended you do. It will probably rectify all the little ticks you're experiencing, and I'm sure you won't hurt it. The 722.6 trans is nearly bullet-proof. That's why they use it on some Jeeps and the Gen I Chrysler 300, Dodge Charger and Magnum and with a few dimension changes the Dodge Challenger (referred to by Chrysler as the NAG1). While you're under there, you'll probably want to replace the conductor plug that's known to leak fluid up into the computer of all places (not to freak you out). Cheap fix if it hasn't already been done. And don't worry about what filter. They are pretty much the same and are intended originally to last 100,000 miles.