Gearbox 8620-1003 for Boxtser S 04/2003

[Gelbster]

Sven,
Marcus and I have posted epic amounts of research on this subject in the previous posts he kindly linked for you. His info is worth a lot. He knows more about this subject (& has shared it !) than many Porsche Tech Departments.
I am acknowledging that because you seem to have lost interest.
Here is a helpful article on the subject from Pelican:
Porsche 911 Carrera Gbox Second Gear Shift Detent Installation - 996 (1998-2005) - 997 (2005-2012) - Pelican Parts Technical Article
$200:
http://www.ebay.com/itm/PORSCHE-TRANSMISSION-996-or-BOXSTER-DETENT-NEW-FIXES-2ND-GEAR-Pop-Out-/151517255422?hash=item234721d6fe:m:m1FHVX0IfU9prwM oY_p80Eg&vxp=mtr
Cheaper from Erik Johnson:
http://www.renntrack.com/forums/showthread.php?1278-Detent-DIY

[Porsche9]

For what it's worth I can vouch for the detent modification. 2nd would every once in awhile pop out and this mod solved the issue permanently. Good luck of getting the issue fixed. As suggested, start with the easy to fix/cheaper possible solutions first before going with the expensive transmission replacement route. Even if you have to replace the trans the other items should be looked into.

[Gelbster]

But if you drive to much after the 2nd gear cluster starts to wear, the detent will not save you.
Replacing the 2nd gear cluster is a really difficult/expensive job. Detent should(imho) be considered wise PM
Erik Johnson has the best price for it.