Mercedes: CLK 430 TRANSMISSION TROUBLE, impending failure, clk 430

Question
I have a 99 clk 430, the tranny makes a slapping banging noise in 1st and second gear, then settles down at higher speeds about 35 40 mph. no check engine light just noise, which returns when downshifting.  the car has 91k on it.  I dropped the pan and there was all kinds of metal chunks, and filings.  Is the tranny a goner? or can it be repaired?  do I have to take the exhaust off to remove?  how can I be sure it's just the tranny and not the bellhousing, or torque converter too?  I put my hand on the tranny pan while the car was running and that seemed to be the epicenter of the banging.

Answer
John,
When metal appears in the trans pan it is a clear sign of impending failure. The transmission will need to be rebuilt or replaced. If you have not removed a transmission before, I strongly suggest that you finde someone who has worked on this particular vehicle. Each model has different sequences to follow in order to "Safely" remove the unit without damage to the engine,car, or more importantly to you.
The transmission will need to be looked at by an independent  transmission mechanic to determine the amount of damage and the price to repair or replace. A low mileage used transmission may be your least expensive route.
Good Luck
Rob