1977 630 4spd to 5spd

[ngrosso]

Hi everyone,

working on a neat project and was offered a 5 Spd out of an m20 e30, Getrag supply number, 260/5.05-ANB
Anyone aware if I could pull this off in a 77 630cs? or how I can find out? Its not the same 5spd that was a factory option for the 630. Cross referencing with realoem didn't get me far. Currently have 4 Spd 262/9.45-CK
Any help or input is greatly appreciated.

Thanks!

[Bert Poliakoff]

Trans from an M20 is a no go. Any 5 speed with a mechanical speedo drive fro a six or five pre 82 will work easily You want the one with a removable bell housing, the proper crossmember for the trans and proper drive shaft I know of a guy parting a pre 82 six with a known good trans and everything should be plug and play Should run you about $1k unless you get very lucky

[DesktopDave]

+2, as Bert says, your 260 came from an M20, so that gearbox won't mount to the M30. The bell housing pattern is different between the M30 and M20 motors, along with the clutches, starters, driveshaft length and sometimes even the output shaft bolt pattern. The gearset is the same, so it might be possible to use it for spares. I'd sell it to an E30 guy & look for the right 'box.

Here's some interesting info from the E9 group that'll get you going in the right direction, using a 260 with a electronic speedo emulator:
https://e9coupe.com/forum/threads/getrag-265-alternative-for-5-spd-conversion.16468/

I've spent quite a bit of time with these cars, so here's a little bit of tranny trivia for you:
The only real 5-speed bolt-in options you have is the Getrag 265 with mechanical speedometer output and the M30 housing. You'll need the matching driveshaft too. It's very hard to find one, and you'll be bidding against everyone with an E3 & E9. Even the E30 M3 had a 265! They're still out there, installed in some early 80s E24 and E12s. You can also find the 265 in manual E23 and a few select years of E28 & late E24, but they won't have the mechanical speedo output. You also have the option of the Getrag 280, but that was only offered in the M5 & M6. The Euro E34 M5 3.8 even got a six-speed, I think those boxes are the 420g (as fitted to the E39 V8) but with an M30-style housing. Apparently there is also an exceedingly rare ZF 5-speed that was used in the early 70s, but I've never seen one personally.

To make things more confusing, the Getrag 260 gearbox was offered with several housing patterns AND in several different versions. The early 260/5 was only used for a short time behind the M30, eventually replaced with the updated 260/6. The M20 cars got three different versions AFAIK: a shallow bell housing /5, the deep /5, and the /6.

I've also heard a few E10/E21/E30 guys running the M30 in their cars. The M10 also uses the same bell pattern, so theoretically it'd be possible to fit the E21 5-speed with cable output ('81-'82 Getrag 245, '83 Getrag 240) to your car. You'd have to use the E21's small flywheel, figure out the subframe, match up the flexdisk, but it's possible that your long 262 driveshaft might mate right up to the stubby 240. The later E21 240 has a compatible mechanical speedo output. I'm not saying it's advisable, but I am saying it's possible.