Is this a transmission problem?
 

Hi-

I have a 2003 300M with about 72k miles on it. I am not the original owner, so I don't have a complete maintenance history.

I have noticed recently that the car is shifting hard, as is, I feel a ka-chunk! when it shifts, but not allways. Usually, it is when I have to slow down rapidly (as in making a 90 degree turn onto a side road) then accellerate rapidly. It usually goes ka-chunk around 20-30 mph during the accelleration. I don't know if the transmission fluid has ever been changed, or if that would even matter. Should I just take it in for tranny service?

Also, when I play with the autostick, I have noticed on a few occasions that when I ease to a stop, sometimes the gear indicator on the dash says I'm still in 3rd gear even when I'm at a standstill. Shouldn't it automatically dropdown to 2 then to 1as I stop? Sorry if this is a stupid question, but I never drove a manual tranny and I don't know if this is normal behavior or not.

Thanks,
-Mark