I have a 90 model 240 that has some remarkable previous owner repairs and attempts at repairs. Oh my. The issue I am working on now is a sunroof that will not operate properly, and will not seat at the rear even when I removed the gearbox and closed it by hand.
I have determined first, that the gear box is broken, and or may have missing pieces. I have another 240 with sun roof that works properly, but am afraid to take the gearbox out of it to study because "it aint broke, so I aint gonna try to fix it." I dont want to end up with TWO non working sun roofs.
Anyone that has a gearbox for sale I am interested. Have read the posts of roof function and they are very helpful.

Putting in a new/used gear motor at this point is useless. You need to find out why the SR will not seat at the rear first. Normal faults include an obstruction (broken piece of plastic, twig)or a broken support arm.

You can test the motor by plugging it in and turning the switch in either direction. If it doesn't move, check the fuse.
--
Keeping it running is better than buying new

There is no motor.
It is manual crank.
I believe the PO either broke it or lost parts of it.

There isn't much to the gearbox itself. If there was a broken part--or missing--it wouldn't do a thing at all. It is held together by a couple of peened over areas on the cover that sometimes fail but if the screws holding the assembly to the roof are tight nothing can escape. More likely as already suggested - obstruction or the rear adjustable link(s) is(are) loose or broken -- or maybe the cable(s) has(have) a stretched or worn area. - Dave

This one was not secured by peened over rivets. I suppose the PO had disassembled it in an attempt to repair a non functioning roof. It contains a gear, a spacer. I cant figure out how it was originally supposed to work, but am pretty sure it has parts missing. Hence, I believe step 1 is to obtain a new gear box.
Thanks

Not much to the mechanism. Handle attached to the 'gear'. The gear gets positioned between the 2 cables. The handle turns the gear, which then pulls/pushes the cables.
--
Keeping it running is better than buying new

It occurred to me to add this--there is a cycle of revolutions to the spinning of the gear. You can't install the gearbox in the middle of a cycle and expect to get full closed--or conversely full open. With the panel fully closed I run the gearbox (before installation) all the way to the closed direction--reach the "STOP"--and then back it up just a little--then install the box and set the handle. When you tried to close the roof manually was the gearbox attached?--if so, the cables engaged with the gear would keep it from moving back any further.
And I would like to clarify what a wrote about the cover being held by peening -- not by way of rivets but the box is stamped in such a way that it locks the cover in place. I have often seen them separated.--Dave

The door would not close manually, even after I removed the bad transmission, so it seems I have two issues. Actually, It will close, but the rear section does not rise to the level of the roof as it should. I recieved a handle from Voloparts yesterday. ( A nice metal one too. ) So round 2 begins.
Thanks for the tips guys.

It's the adjustable rear links that control the lift. - Dave

Well, I followed your instructions and attempted to adjust the rear hatch height. It doesnt seem to be cooperating. the adjuster on the driver side wants to rotate while tightening. The crank gear slips on the cable when the roof is nearing closure. I suspect previous owner misguided maintenance has something cahwonkas. If I alternately push on the rear of the roof alternately on each side, and crank it closed, I can get the roof to line up.

During my maintenance restoration, I blew out the front drains from the roof, and the rear drains from the trunk. I then washed the car. When I drove it an hour later, I got a water bath about my head and shoulders.!! I thought the design was for the roof to leak but drain safely.?
Anyway, I have a spare cable assembly, but replacing the old one makes me wonder if I will make things worse. hmmmmm. Can they be worse?
Thanks