The tension rod sits under the cover plate as the picture shows. The tension rod sits on the cover plate. Here is copy of instruction for adjusting tension rod. Note instruction shows when part #80 is removed you will see the tension rod and a small bearing sleeve.....
1) Tension Rod Adjustment. Referring to #24 (Rod, Draw), it threads into the Wedge #23. Typically, it needs one or two more turns (clockwise) to enable sufficient tension with the tension lever. In order to get to the rod (it is pretty easy, just takes a couple of minutes) Take off the plastic cover (#71) by taking out the 4 screws (#44). Just loosen the whole assembly and move it out of the way. Remove part #26 and part #80. You will see the tension rod and a small bearing sleeve on the "L" end of the tension rod. Set the sleeve aside. The rod is flexible enough to turn it without removing anything else. I suggest one CLOCKWISE turn, partially reassemble, test the tension and take up another turn only if necessary. I set mine to get proper tension at a 3 to 3-1/2 setting on the tension lever gage.