Until today the sunroof in my '85 XJ6 VDP would open but not close, at least not without great difficulty. I took out the motor thinking maybe the grease had dried up. That was not the problem, but the problem was just as easy to fix.

There is a sort of armature positioner that has a threaded shaft with a nut to hold it in place. That had backed out on my car (see picture). So when the motor worked in one direction (opening) the armature would be pushed into the motor and it worked fine. But in the other direction (closing) the armature would come partly out of the motor (see red arrow in picture) and then the motor would become weak. I tightened the shaft down so the armature was pushed in, but not too tight. The threaded shaft has an allen head in it to tighten it with. Then I tightened the lock nut on it. (Note: the motor itself has English sized bolts and nuts.) Put it all back together and it works fine now.

I wish I could say you didn't have to take the whole motor out to do this, but because of where the motor is mounted you can't see or touch this external threaded shaft without taking the motor out of the car. Still that isn't that bad a job. Took me three hours total, including clean up time. Note you wouldn't have to take the gear off the motor like I did. The 2nd picture shows where this threaded shaft is on a closed-up motor. Then again if you get this far you might as well freshen the grease even if it doesn't really need it.

-mB

 

Its always nice when the fix is simple!!

 

I had the exact same problem!

 

great write up!