C4 picasso Aisin Transmission T40mm screw

[LeL]

Hi,
I just found out my C4 Picasso 2016 Aisin Transmission screw has rounded, the Torx T40mm. I cannot unscrew it to change my transmission oil.

What can I do? what is the size of this T40mm screw if I were to get a new screw?

thks,
LeL

[xantia_v6]

It is a special screw, you must get it from the dealer (although the same part may be used on other makes which use the Aisin transmission).

You can probably loosen it by hammering in a hex bit or a torx bit that is slightly larger. You will see that the surrounding plug has a hex on it and can be unscrewed, but you would need to partially drill the stripped screw before you can get a tool onto the hex.

[moizeau]

You can't change the gearbox oil by unscrewing that screw. It's a level plug screw. Get both from a dealer with oring for the level plug screw and then take the outer one out.

[xantia_v6]

You can't change the gearbox oil by unscrewing that screw. It's a level plug screw. Get both from a dealer with oring for the level plug screw and then take the outer one out.

You can't get a tool into the outer plug until the inner screw is removed or (partially) drilled out.

[LeL]

Will this help? Is it suitable? From aliexpress. https://www.aliexpress.com/item/1005004826718207.html

[LeL]

Sent to workshop and they just a hammer , Torx 40mm to take it out. They just tap into the "rounded" screw, secure it tight and start unscrew it gently.