Has anyone experienced problems with the xray plastic caps on the the end of the driveshafts that go in the rear diff out drive cups fitting extremely tight ? One side is smooth and slides in the out drive cup a bit , the other side was extremely tight and would not slide at all even with a good amount of force. I removed the plastic cap and cleaned it up a bit by lightly sanding it , helped a little but still quite a bit tighter than being able to move easily. S1 standard gear diff cups by the way and the 50mm swingshafts.