[W126 Coupe] 722.6 Transmission Problems

[Pavel]

Hi guys just bought a w210 97 e420 with 108k that has tranny issues.  When
the car idles in P there is a rattling coming from the tranny.  As soon as
you put it in D or R the rattling goes away if it will in gauge into gear. 
When you drive and slow down to about 5mph it jerks like someone rear ended
you and makes a noise like worn brake pads against a rotor only louder. 
Finally sometimes it will just come out from a gear and not go anywhere
will just rev up.  Or not in gauge into gear from park.  When it does
ingauge it shifts perfect. Any suggestions or should I start looking for a
new tranny?
thnanks
Pavel

380sec
560sec
560sel
300cd
e420