What is the difference between a 2 speed and 3 speed wiper transmission? I couldn't find a whole lot of pictures of them floating around the internet. I'm restoring a '70 Barracuda where the previous owner set up everything for a 3 speed wiper except for the wiper transmission which is a 2 speed. I've been told that you can modify a two speed to make it work. Has anyone done this? Thanks!

When you say transmission are you referring to the pivot if so the are the same 2sp to 3sp.If you are referring to the gearbox on the motor you would need to change the crank arm on the motor and also the linkage that goes from the crank arm to the left wiper pivot.

This explains it: http://www.passion4mopars.com/Mopar-2-Speed-to-3-Speed-Mopar-Wiper-Motor-Conversion_b_1.html
If you have any questions call Kim at Passion 4 Mopars (above link), she is always willing to talk/help.

Bottom line, the motor crank arm and the rod from that arm to the drivers side pivot are different between the 2/3 speed. If you take those parts off they have the part numbers stamped into them.

Okay great! Thank you both for your help.