C220 Transmission

How much would a use transmission cost?
My 94 C220 has problem shifting when I reach 30 MPH. What could be cause. I had changed the Transmission and still not working.
I need help with this
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.