335 & M3 6MT Question

[2013E92M3ZCP]

I'm curious about the differences of the manual 3 pedal gearbox between the 335 and M3. Same manufacturer? Major differences? Stronger? Different synchros to cope with additional power? I couldn't find anything when I searched.

I have a 335 with UUC Evo 3 which I like. I'm hoping its similar so when I can justify the upgrade, I won't be disappointed.

By the way, I drove a DCT manual today at Oktoberfest. I love my 335 but WOW, you guys are lucky!! (but I'm a traditional row it yourself kind of person which is why I'm asking)

Thanks in advance!

[mixja]

I think it is the same gearbox, just different final drive ratios...the 335i is even taller than the tall M3...

[BPMSport]

I was also under the impression that the 335 and M3 share the same gearbox. Upon doing some research, it appears that although they are very similar - they are, in fact, not exactly the same.

The 2009 335i 6MT is equipped with a "GS6-53DZ - THGX" gearbox, BMW part number 23007571423 at a wholesale cost of $5,585.08 + core. Wow that's pricey! Then again I just paid over 4K to AAMCO to rebuild the entire transmission in the Jaguar I just acquired, so maybe it's not to far out of range.

The 2009 M3 6MT is equipped with a "GS6-53DZ - TJGC" gearbox, BMW part number 23002283601 at the same cost of the 335i transmission. I have no idea what the designations TJGC and THGX mean, and what the differences are between them. I am however curious enough to do some more research in attempts to find out.

Regardless, I really miss the Getrag unit that was found in the E46 M3. So much more of a solid transmission - and BMW would never think of sharing it with the non M model.

[FStop7]

Probably a different input shaft or something like that.

[BPMSport]

Originally Posted by FStop7

Probably a different input shaft or something like that.

Now that I think about it... It has to be a different bell housing because the M3 is a V8 and the 335 is an I6. I'm fairly certain that that's the main difference and that the internals are more or less the same.

[!Xoible]

Originally Posted by BMW335i2007

I'm curious about the differences of the manual 3 pedal gearbox between the 335 and M3. Same manufacturer? Major differences? Stronger? Different synchros to cope with additional power? I couldn't find anything when I searched.

I have a 335 with UUC Evo 3 which I like. I'm hoping its similar so when I can justify the upgrade, I won't be disappointed.

By the way, I drove a DCT manual today at Oktoberfest. I love my 335 but WOW, you guys are lucky!! (but I'm a traditional row it yourself kind of person which is why I'm asking)

Thanks in advance!

just drive the goddamn car man

[MrHarris]

I have the UUC Evo 3 w/ DSSR and it's much, much better than stock but in all honesty I feel my old e46 330i w/ full rogue SSK was better.

[MMMorish]

I know that the M3 tranny has synchros made of CF. I'm not sure if the 335i tranny has the same.

Either way, my tranny just replaced and my second tranny seems to be a lot better than my first one. Like MrHarris, I have a UUC SSK w/DSSR and like MrHarris said, it's a lot better than stock.

Hey MrHarris, does your DSSR slop from side to side at all?

[mkoesel]

Another difference between the M3 and 335i transmissions, I believe, is that the m3 has an additional cooler I think. Not sure if that could also contribue to slight differences in the transmissions as well, or whether that is a completely external part/assembly that could in theory be added to the 335i gearbox as well.

Originally Posted by Mike@Powerchip

Now that I think about it... It has to be a different bell housing because the M3 is a V8 and the 335 is an I6.

I agree the bell housings must be different, but I wonder if the transmission part number includes the bell housing too or if that is separate?

I'm fairly certain that that's the main difference and that the internals are more or less the same.

I agree the internals are essentially the same - right down to them having identical ratios, in fact.

[2013E92M3ZCP]

Thanks for the replies so far. It's hard to compare since I have the UUC now on the 335 and these days finding a 6mt at the dealer is almost impossible (not many M3s at all, and if they do, they are DCT).

[lucid]

Originally Posted by mkoesel

Another difference between the M3 and 335i transmissions, I believe, is that the m3 has an additional cooler I think. Not sure if that could also contribue to slight differences in the transmissions as well, or whether that is a completely external part/assembly that could in theory be added to the 335i gearbox as well.

+1

It is possible that the M3 transmission has some additional connections for the fluid lines that run to the external cooler, which sits in front of the right wheel arch. Not sure how the circulation in those lines are achieved in the M3.

It might be mounted to the chassis somewhat differently as well for a stiffer connection. (Even then you can feel the tranmission shifting around slightly on the stock rubber mounts at the the track, which is expected).

If one really wants to know the external component differences, one can dig into the bmwfans website and compare the two units:

http://bmwfans.info/parts/catalog/E9..._transmission/

[SlammedR8]

All I can tell you is that,
it feels A LOT better than the 335s I have driven.
Its much stiffer, and you really KNOW when your in gear, it just clicks! Cant explain it!

[zuggerat89]

Originally Posted by !Xoible

just drive the goddamn car man

hahaha your name... Russell Peters.... so funny

[ericld]

Based on my experience the M3 6MT is a LOT different.

The gears on the M3 are square cut as opposed to angular so they don't "ride up to the tooth edge" under high RPM and torque situations. (yes I know the 335 has more torque).

This makes for a noisier and rawer sounding and feeling gearbox. Once you get used to this chatter and grind, though, it's a very pleasing experience. Music to the ears. Racecar-esque.

You can hear the mechanical sound of the gearbox beneath your seat.

[mkoesel]

Originally Posted by ericld

Based on my experience the M3 6MT is a LOT different.

The gears on the M3 are square cut as opposed to angular so they don't "ride up to the tooth edge" under high RPM and torque situations. (yes I know the 335 has more torque).

Did you determine that from reading some document or looking at a cutaway view of the transmissions? Or are you just going by the sounds?

[JCtx]

Originally Posted by Mike@Powerchip

It has to be a different bell housing because the M3 is a V8 and the 335 is an I6.

If trannies include bell housing (a big 'if'), then clutch is probably included as well. Do they have the same clutch? I expected the M tranny to be unique, but guess not.

And I don't think the M3 has 'tall' gearing. On the contrary, I thought it had short gearing (74 mph @ 3K seemed like screaming to me), but with the theoretical top speed of 205 being pretty close to its unrestricted one (190?), I consider it normal. A Corvette is tall, with over 250 mph theoretical top speed. Good day.

[novablackm3]

not the same, at least when i drove them. i also drove a i135 6mt and a z4Sdrive35. In the Z4 the shifter was too smooth compared to the m3. having driven all 4 i have to say i kinda like the notchyness / stiffness of the m3 6mt w/ my RE SSK

[jbeene]

Sort of related to the post but definitely related to how different the m3 shifts in relation to the 335i.

AFIK the M3 doesn't have a cdv - the part is there but it comes bored out from the factory instead of having to do an aftermarket fix. Clutch take up is much smoother and more linear.

Have had both cars and the shifts, for whatever reason (I'm sure there are many) are much more direct in the M3.

[BPMSport]

The M3 does have a CDV - I had it removed. Although it seems much less restrictive than it was E46. I think it's called something different though.

From looking at it, it doesn't seem like it even restricts the flow at all. However, I feel a clear difference with it removed. It is shown on the parts list of the clutch lines.

[bruce.augenstein@comcast.]

Originally Posted by ericld

Based on my experience the M3 6MT is a LOT different.

The gears on the M3 are square cut as opposed to angular so they don't "ride up to the tooth edge" under high RPM and torque situations. (yes I know the 335 has more torque).

This makes for a noisier and rawer sounding and feeling gearbox. Once you get used to this chatter and grind, though, it's a very pleasing experience. Music to the ears. Racecar-esque.

You can hear the mechanical sound of the gearbox beneath your seat.

I can't find a reference to this, and frankly, I don't believe it. I don't own one, but on two test drives (one easy, one with max revs), both M3s had smooth sounding gearboxes. No rattle, and essentially no whine. Nothing like that old Muncie "rock crusher" sound and feel that you get from straight-cut gears.

Yeah, straight-cut gears are stronger than helical cut, and you don't have to bother with the bearings restricting fore and aft movement due to the side loads generated by helical-cut gears, but hey, nobody does this on the street unless they've got a gearbox undersized for the engine's torque.

In regard to torque, the M3 is arguably easier on its gearbox than the 335 is, because gearboxes and drivetrains only care about torque per cylinder - so there's no need for anything "special" except possibly for those carbon fiber synchros which I assume are there for reduced rotating inertia reasons.

Bruce

[dougman]

This is the most bizarre thread I've read in a long time. As a former automotive engineer I tend to pay a lot of attention to the guts of my beloved M3.

The gearbox does not have carbon fiber synchros. Sychros are friction surfaces that spin up adjacent gears allowing the "dogs" to mesh. Carbon fiber would be a terrible idea in that application.

The gearbox does not have straight-cut gears. If it did, you would hear it coming a mile away. For a while, some cars used straight-cut gears on reverse but helicals on forward (and you could clearly hear it in reverse), but now almost every car has helical gears on reverse, too.

Gearboxes only care about torque per cylinder? Another one I can't understand. Gearboxes transmit engine torque to the driveshaft. All of it.

The gearbox is very similar to the one in the the 335i. As some have noted, the ratios are identical. The base part number is the same with a different suffix.

The one difference I AM confident of relative to the 335i is the dual-plate clutch.

[dhoggm3]

I'm no expert, but I have a 335 and an M3. The M3 box definitely feels less vague, more direct.