I did a writeup on the 5th gear swap for the 944 transaxles. Not sure how similar/different the 924 boxes are.

http://944hybrids.forumotion.com/the...p-pdf-t289.htm

Use the PDF linked further down in the page.

EDit: Looks like the link has moved. Let me see about getting that fixed. Otherwise i have the PDF at home...

 

There is one major difference. The bolt used on the main shaft is not the same in the 951 box as in the 944 NA boxes. If you torque that bolt down to level you use for the allen head bold you can break the bolt head off. I found out the hardway.

 

I don't believe they're different, it's just that the bolt should not be re-used. I've done the 5th gear swap a few times, and i always use a NEW 10.8 bolt with plenty of loctite.

 

Here ya go: http://944hybrids.pbworks.com/w/page...-5th-Gear-Swap

 

No the bolt is not the same. That proceedure shows a 12 point bold. The one in the NA boxes are standard bolts. 13mm or 17mm socket size I forget. If you use the torque in linked proceedure on these bolts they will break off. The factory manual has a much lower torque. I think about half. Otherwise the proceedure works reasonably well. The hardest part was getting the pin out of the forks.