help me help my sunroof

[turbobenz]

im getting the sunroof working on my 300sd w126. Before I started, it was closed fully and the only thing it did was make sound from the motor turning in the trunk. I figured it was a broken cable so i decided to tackle it today. I was able to manually push the sunroof open, and could close it but not get it to tilt back up. So i took apart the track and pulled the entire thing out. Apparently the owner before me (ernie of ernies ind. mercedes service) had it for 8 years and decided at one point to remove the cable entirely so he could close it, i guess. So i took the cable from my w123 parts car and fed it down into the track and then pressed the button to feed it. It will not feed in unless you help it, but it pushes fine. When its retracting, it grinds unless you help it, again, pushing out (as if the sunroof were closing) it works fine. Any ideas? Im thinking its down in the motor (the gear may be stripped, this car has 354k on it). Has anyone had this problem before? Is a w123 sunroof cable the same as a w126?