[marconi118]

1M shaft should be direct bolt on to a 135i + M3 LSD
for a 335i you should lengthen the 1M shaft
the 1M is a 135i + M3 LSD + M3 suspension!!!!!!

[1&done]

Originally Posted by marconi118

1M shaft should be direct bolt on to a 135i + M3 LSD
for a 335i you should lengthen the 1M shaft
the 1M is a 135i + M3 LSD + M3 suspension!!!!!!

That's my understanding, however, the two driveshafts are deferent in length: 135i=1371mm ('08 MT)
1M =1339mm

Maybe the 1M/M3 Diff. is longer
(Real OEM)

[AutoTechnique]

Originally Posted by 1&done

To the OP...Not trying to I am just trying to get some facts and details for doing this mod in the 135. Maybe one day this will be a sticky.

Here by us, the OP is well known. There aren't too many 135/335 running around with decent mods. Every time there is talk of a 135/335 George's name comes up.

Originally Posted by 1&done

Maybe the 1M/M3 Diff. is longer
(Real OEM)

You got a point there. When we had the two diffs next to each other, the M3 diff was longer... I just didn't measure by how much.

[1&done]

^ that is good know I am going to start the process...

[GeorgeSmooth]

Originally Posted by 1&done

^ that is good know I am going to start the process...

The best thing to do since you already have the 135 propshaft is to get the E90 or E92 prop and get a company to match the two for length. Then try source the 1M driveshafts and you sorted.
If you cannot find the DCT ratio for the M3 diff try diffsonline.com instead of paying the agents for a complete diff, I am sure they will have a 3.15 ring and pinion in stock.

[marconi118]

The only fixed point in the car (135i or 1m) is the location of the center bearing.

Distance from the bearing to the gear box flange depends on the gearbox length (N55 or N54 one are different)

Distance from the center bearing to the diff depends on the diff.

1M shaft will fit 100% the N55 135i because the 1M uses the N55 gearbox.

On a 135i with N54 the 1M shaft will fit exactly from the LSD to the center bearing, but has to be shortened by aprox 15mm at the gearbox side

MEASURE ON THE CAR ITSELF the distance between the center bearing and the gearbox to let the shop shorten the shaft. The side from center bearing to the LSD has to be from an 1M and not modified.


For my N54 335i I used a M3 DCT shaft, shortened at the gearbox side aprox 20mm and fitting the 335i gearbox flange

[Nigelo]

I am now starting to have dreams about this thread - Apr 07 manual 335i so have a welded diff and being in the UK quaife and wave track are the main (and expensive) options. I'm starting the ebay stalking now for the diff and drive- and half- shafts.

Is it really as straight forward as
-Remove oem diff, driveshaft and half shafts.
-install m3 diff and half shafts.
-chop diff end off m3 driveshaft and get it joined to gearbox side 335i shaft (after the 335i centre bearing)?

Thanks guys

[idnan]

Hi Nigelo I've done the conversion (might be the only one in the UK).

What you've said is correct, although you might be better off getting the whole m3 subframe like I did and you'll have the better bushes and arms that the m3 has. If you have any questions or need any pics, please let me know as I'm removing the rear subframe and propshaft in the next couple of weeks.

[Nigelo]

So, M3 subframe bought and should be winging its way to me as we speak / type.

Think its coming with nearly everything except the wheels and prop (so diff, springs, shocks, brakes, roll bar etc etc)

If it does come with all of this, can I remove the M3 hubs and brakes from the subframe and pop the 335i ones on, then install the entire modded M3 subframe without issue?

The final piece of the puzzle is then 'just' the prop.

[GeorgeSmooth]

When one of you guys have the M3 driveshaft and 335 driveshaft on the ground please take measurements. I have a feeling the M3 shaft will not fit a 135 hub or will have to go too deep in. From what I have seen the hubs on a 135 are ever so slightly closer too each other. By driveshaft I mean the short shafts attached to the wheels.

[1&done]

[JMARS]

I just read all of this and it made my head spinn..

So please correct me if I'm wrong: I have a 6mt car so I would want a DCT 3.18 M3 Diff because its the closest to the 3.08 I currently have. I would also need to Marry the 335i Tranny side of the drive shaft to a SHORTENED side the an M3 drive shaft... What about the axles?
And is that it???

[BigBoosting]

You have to use the M3 axles and supposedly the axles bolted right in on his car. It was an auto car though, not sure if they have the same size axles as the 6MT cars.

[Nigelo]

Hey JMARS! I'm in the middle of doing this swap.

Easiest route is M3 dct diff, M3 driveshafts, and then a hybrid propshaft. There's a couple of ways to do the prop:

Slightly shortened full M3 prop with a 335i gearbox flange.

Or

335i prop with shorter diff end, made from a M3 prop or as mentioned earlier on, one of a select few e38s or e39s.

If you want to swap in a whole M3 subframe, then it's a little bit trickier if you are keeping the 335i brakes. Custom toe arms are needed for the 335i hubs.

[BigBoosting]

Originally Posted by Nigelo

Hey JMARS! I'm in the middle of doing this swap.

Easiest route is M3 dct diff, M3 driveshafts, and then a hybrid propshaft. There's a couple of ways to do the prop:

Slightly shortened full M3 prop with a 335i gearbox flange.

Or

335i prop with shorter diff end, made from a M3 prop or as mentioned earlier on, one of a select few e38s or e39s.

If you want to swap in a whole M3 subframe, then it's a little bit trickier if you are keeping the 335i brakes. Custom toe arms are needed for the 335i hubs.

Is your car 6MT? I really want to make sure the M3 axles (driveshafts) fit into the 6MT car hubs.

[JMARS]

Originally Posted by marconi118

Yes the M3 shaft will end up shorter at the trans. will need to be measured on the car. I assume between 15 and 30mm

Then will need to machine this adapter, with 6 holes: 3 screws for the M3 axe on a circle of 105mm and 3 screws for the 335i gearbox on a circle of 95mm

So will it be shorter or longer???

Originally Posted by Nigelo

Hey JMARS! I'm in the middle of doing this swap.

Easiest route is M3 dct diff, M3 driveshafts, and then a hybrid propshaft. There's a couple of ways to do the prop:

Slightly shortened full M3 prop with a 335i gearbox flange.

Or

335i prop with shorter diff end, made from a M3 prop or as mentioned earlier on, one of a select few e38s or e39s.

If you want to swap in a whole M3 subframe, then it's a little bit trickier if you are keeping the 335i brakes. Custom toe arms are needed for the 335i hubs.

I think you mean "M3 dct diff, M3 half shafts(rear axles), and then a hybrid Driveshaft" right?

[Nigelo]

Hey, yeah.... Just a bit of cross-Atlantic word differences!


Haven't got round to changing the side shafts over, but Idnan off here has done it already I think. I'll go check realOEM and see if the securing nut is the same, might suggest a similarity.

[Nigelo]

Just checked - Idnan has done the swap and his is a manual car.

[idnan]

The m3 output shafts fitted into the 335i hubs fine and I ran it with that combo for a few months. I can get a few comparison pics as I have all these parts off the car at the moment.

The issue I found with using the m3 subframe with the 335i hubs was that the toe arms no longer fit. I suspect it was because the mounting points on the hubs and subframes are different between the m3 and 335i but I cured that problem by using adjustable toe arms. This setup worked fine but George Smooth could still be right in that there are other differences with regards to where the shaft sits in the hub.

On a side note, the m3 output shafts are much beefier than the 335i ones so risk of snapping them on the drag strip should be less.

[JMARS]

NICE! That would be great!

[JMARS]

anybody know where i can find a rear DCT M3 clip like this in south FL????

[RimasRS]

Originally Posted by Nigelo

Just checked - Idnan has done the swap and his is a manual car.

Please somebody confirm or deny. Does the M3 sideshafts fit on oem subframe with DCT 3.15 diff? Because N54 have 86mm long sideshaft and the M3 sideshaft is 102mm acording to realoem.com

N54 Sideshaft http://www.realoem.com/bmw/showparts...g=25&lang=enUS

M3 Sideshaft http://www.realoem.com/bmw/showparts...g=25&lang=enUS

So do they fit or do you have to shorten them?