Automatic Transmission slipping on 1966 230S W111 - No torque convertor??

[VintageBenz.org]

On my way to the office to change out the filter and fluid my poor ole girl was applying the power when it was in gear. Felt like a bad torque convertor to me. So after a little reading I find that these cars didn't use a torque convertor. I am hoping to change the fluid and filter to resolve the problem.

If not what do I try next?

Anyone have a guide to changing the filter and fluid? I haven't checked my star classic CD but I have a feeling it is not going to show me what I need.

Also are Dextron II and Dextron III a suitable fluid? I saw a service bulletin that said to use Dextron II.

Thanks as always!