Different Driveshaft for Diff Swap?

[NickZHP]

I picked up a 3.46 diff from an automatic 325i the other day and I want to replace my stock zhp diff with it. I know I have to switch the input and output flanges from the stock diff to the 3.46 diff but I came across this thread today claiming the driveshaft has to be replaced as well on the 330. https://forum.e46fanatics.com/showthread.php?t=529965

I have yet to see another post or comment anywhere mentioning that the driveshaft has to be replaced to fit the other diff. Am I missing something here?

[derbo]

I picked up a 3.46 diff from an automatic 325i the other day and I want to replace my stock zhp diff with it. I know I have to switch the input and output flanges from the stock diff to the 3.46 diff but I came across this thread today claiming the driveshaft has to be replaced as well on the 330. https://forum.e46fanatics.com/showthread.php?t=529965

I have yet to see another post or comment anywhere mentioning that the driveshaft has to be replaced to fit the other diff. Am I missing something here?

You should be fine. The mention is the input flange of the differential being a 6-bolt design. Replace the input flange from your 3.07 to the 3.46 and you will be running in no time.

[Reasoned1]

That is my understanding as well; however, swapping input flanges is more involved than swapping output shafts, which is why I went with an input flange-compatible 3.38 gearbox.

[derbo]

That is my understanding as well; however, swapping input flanges is more involved than swapping output shafts, which is why I went with an input flange-compatible 3.38 gearbox.

This is probably why I went with an M3 rear end swap as it is plug n play with M3 Driveshaft. Oh, and LSD. :)

[NickZHP]

Thanks all, would've loved to go with the m3 rear but I couldn't pass up this diff for how cheap it was. Here's a decent write up I found about changing the input flange in case anyone needs it, http://forum.e46fanatics.com/showthread.php?t=788077