Kimmo

I'm surprised to read the roof worked after using the manual override; after having the latch drive unit apart, that makes no sense to me. When you poke an allen key in, it engages with a steel shaft with a worm drive on the end, which bears on a brass gear on another steel shaft with splines poking out of the unit, which engages the flexible drive shafts... so far, so good. But closer to the allen key socket, there's a little splined section which holds a plastic gear which bears on the worm drive from the motor. There's no way you can spin a worm drive by turning the gear engaged with it; it just wants to push the worm along and it can't. I figured this explained why that gear was plastic instead of brass; it's sacrificial. Either the splines will strip, or in my case, the gear just broke in half. Anyway, in the end I figured out that these TS/Mk4/G Astra convertibles share parts with E46 BMWs. If you search 67618370816, you'll find an aftermarket brass replacement for the plastic gear. Replacing the plastic gear with a brass one will prevent the manual override from working, but then again the gear won't strip like a plastic one would, which I'd guess would account for >90% of the reasons for needing to use the override. Also a bloke called Mike Ellis made a very detailed guide all about these roofs; I've got a copy up here (I gather it's public domain). I posted a detailed explanation of my experience fixing one here: https://www.astraownersnetwork.co.uk/threads/ts-mk4-g-astra-convertible-roof-latch-motor-fix.377009/#post-6232746 which includes a how-to on reducing the friction in the latches to stop the motor stalling.