E34 manual swap

[Kamz e34]

Hello everyone, i am having some problems with my e34 525i m20b25 transmission, so i am thinking of doing a manual swap, which transmission would be the best option? I was reading on forums that i could do a 6 speed swap too, what do you guys recommend? Thank you

[82eye]

the G260/5 most commonly found on e30's would be the easiest for plug and play. it's a factory set up that was an option on the e34.

[dannyzabolotny]

With an M20, doing the Getrag 260 swap is the only straightforward option. You can kiiiinda bolt up a 5-speed or 6-speed from a later M50/M52/M54 motor but not all the bolts line up and you need a custom crossmember + modified shift linkages to make it all work, since the M20 and M5x motors sit at a different angle. You really gain nothing with a 6-speed compared to the stock G260 that you'd find behind a factory manual M20 E34, since the G260 has an overdrive 5th that's roughly equivalent to 6th gear.

[Kamz e34]

I am new to bmw manual transmissions, what is the overdrive 5th gear? How does ir work? And the G260 are all the same or there shoulb be numbers?