[RonC]

I wouldn’t take it apart if it was just rebuilt? Try this. Use 3 and 1 oil. The original Trico oil for maintaining wiper operation is similar to 3 and 1 oil. Hook a rubber tube up to the wiper and put the other end of the hose in some 3 and 1 oil (pour some in a small cup). Manually work the wiper blade back and forth (you can leave the motor attached to the car). This will cause the wiper to "suck" the oil though the rubber tube into the wiper. This is good wiper maintenance to do occasionally. Inside your motor is a leather rectangular "paddle" that swipes in a semi arc inside the half circle case. The oil helps to keep this paddle pliable which provides a better seal between the paddle and the case.

If that doesn’t work, check that you are getting enough vacuum with a vacuum gauge. A reading of at least 15 in. Hg or greater would be normal at idle. If all fails I would return it to the rebuilder prior to opening it up.