S6-37 6mt swap info (broken off from junk yard thread)

[bigjae46]

Permission to revive an old thread..



I've had the 330 ZF GS6-37 in the M3 for several years now with 330 Valeo Single Mass Flywheel Clutch kit and it's been great. Love the notchy-ness. Drives and shifts amazingly well.

The ZF in the 330 was the most enjoyable manual transmission experience I have ever had! I'd describe it as crisp and precise yet smooth. It won't let you miss a gear. The 420g and E9X M3 had a rubbery and vague trait. The F and G chassis have the same shitty feeling which is why I don't understand the desire to keep a manual. The experience is bad and I don't see any effort to make it better. BMW just does it to shut the old people up.

[George Hill]

with 330 Valeo Single Mass Flywheel Clutch kit and it's been great. .

What kit is this, can you share the pn#?

[xUltra]

What kit is this, can you share the pn#?

There might be better options available but this is what I have installed in the GS6-37:

BMW Flywheel Conversion Kit - Valeo 835101

[Bry5on]

I'll let George Hill have the official honors but he measured the bell housing to flange difference of both gearboxes today and found the ZF to be 2.5mm longer than the Getrag. Wanted to make sure this number didn't get lost!

[George Hill]

We know the internet puts M3 differentials in non-M 6spd cars so this should work for Bryson's setup as well. But I don't always believe everything on the internet, except they are correct in this instance. The GS6-37 is 2.5mm longer than the 420G and they both use a 96mm guibo, note IIRC the M3 guibo is "thicker" than the non-M the M3 should be used either way.




One of the things I was hoping for in the idea of the 420g to ZF swap would be some weight savings but the weight savings is literally 0lbs, lol.

GS6-37




420G

[bigjae46]

Holy whiteness! Nice legs bro!

The only downer I can think of is clutch disc selection which won't affect everyone. I know UUC used to sell a kit...lol

[George Hill]

Holy whiteness! Nice legs bro!

Wait til you see that sock tan line! lol. Only so much time before the scale times out and turns off, ha.

[Bry5on]

There actually is some small weight savings: the tuned mass damper! That’s gotta be good for 3lbs. It’s located in literally the least impactful place to drop weight though.

[e46IX]

Permission to revive an old thread..



I've had the 330 ZF GS6-37 in the M3 for several years now with 330 Valeo Single Mass Flywheel Clutch kit and it's been great. Love the notchy-ness. Drives and shifts amazingly well.

The only issue I've had is the cross brace touching the midpipes.

I have had the cross member shaved off enough without structurally compromising it's strength and was able to clear it. Now the car runs an aftermarket exhaust and has slightly less clearance than the stock exhaust unfortunately. The midpipes expand with heat and slightly hit the cross member causing a slight vibration / metallic noise which is mostly audible during higher revs.

An idea I had recently was to use a bit of exhaust wrap in that section to reduce or possibly eliminate the vibration and noise.

Curious, what kind of solution did you come up with for your swap?


Regarding all the comments and questions around the potential grinding that can occur during aggressive 1st to 2nd shifts:
I did notice some grinding when aggressively shifting from 1-2 in the early days of the swap. It's been a long time since i've had that happen ever since I slightly adjusted the ZHP shift knob and angled it toward the driver seat. Once I seated knob toward the driver seat and made sure to always shift 1-2 against the wall, it's never been a problem. This is with a UUC 330 SSK, which i'm honestly not a huge fan of. I run Motul Competition gear oil in the transmission. Just make sure to take it easy when its cold from 1-2. Autosolutions will probably be my next upgrade since the UUC SSK is very mediocre at best.

I took an angle grinder to the cross brace and went to town until there was enough clearance from the midpipe.

I've got 3 E46 M3's running around locally now on ZF 6MT gearboxes.

Maybe I've had better luck with used transmissions but none of them seem to be grinding from 1-2. I just put MTF-LT5 from the dealer in there, nothing special.

Mind you I'm also running stiffer engine and trans mounts on these cars, maybe that helps with the grind, less movement.

[chris719]

I took an angle grinder to the cross brace and went to town until there was enough clearance from the midpipe.

I've got 3 E46 M3's running around locally now on ZF 6MT gearboxes.

Maybe I've had better luck with used transmissions but none of them seem to be grinding from 1-2. I just put MTF-LT5 from the dealer in there, nothing special.

Mind you I'm also running stiffer engine and trans mounts on these cars, maybe that helps with the grind, less movement.

IMO after driving 3 Z4Ms, some of these gearboxes do it, and some don't, and I have no idea why.

[Bry5on]

If you’re doing this conversion, be sure to grab as many of the donor e46 330i parts as possible, as they’re skyrocketing in price.

Exhibit A (you need two of these, which is insulting):

[George Hill]

And if you are feeling adventurous there are these, if the shipping wasn't so much I give them a try:

• https://www.ebay.com/itm/206195517356
• https://www.ebay.com/itm/298499116506

[liam821]

What kit is this, can you share the pn#?

There might be better options available but this is what I have installed in the GS6-37:

BMW Flywheel Conversion Kit - Valeo 835101

Yeah, you can get it from rockauto here: https://www.rockauto.com/en/moreinfo...31328&pt=12825

[liam821]

We know the internet puts M3 differentials in non-M 6spd cars so this should work for Bryson's setup as well. But I don't always believe everything on the internet, except they are correct in this instance. The GS6-37 is 2.5mm longer than the 420G and they both use a 96mm guibo, note IIRC the M3 guibo is "thicker" than the non-M the M3 should be used either way.

That is weird. Realoem lists the e46 "zhp" manual gs6-37 driveshaft at 1444mm, while the M3 is 1404mm. I'm assuming the bellhousing mounting location is in the exact same spot between the two - where is the 20mm?

I looked for a gs6-37 transmission for my "daughter's" 330i, but they were either more than I'd want to spend or had a million miles. I ended up sourcing a 420g M3 6spd and will be using an M3 driveshaft, m3 clutch kit, and an non-m 3.48 diff from an automatic 330i.

[George Hill]

where is the 20mm?

The M3 diff is longer, making that distance shorter.