Mr Delano,
You were on borrowed time because mine failed at 120kmiles.
Look for a new one? as in new(used one) one for the car, NO! A new one or rebuilt yes! The 722.3 to 722.5 are good for 120k to 160k miles. 722.6 is good for 170k to 200k miles
If you are a DIY'er, I would rebuild it. The rebuild kit for Mercedes transmission is about $240 bucks.
If you continue to use it, you will pit and scratch the mating "steel plates" in the clutch pack. See picture
If you decide to fix it, I can help you. It is simpler than my 722.5 which a active thread is going.
http://www.peachparts.com/shopforum/tech-help/321329-722-5-tear-down-side-start.html?highlight=722.5
Best of luck,
Martin