The manual transmissions can take gear oil or the M2C134D UTF. Most folks use the 134D UTF in both sumps because of the possibility of the seals leaking between them.
Here's a link to the parts diagram for the transmission case for that 4 speed transmission. You can see the back wall of the trans that meets up with the rear end sump. is it one of the holes that the shift rails go through in the picture, or is it something else?4 speed transmission case