Need help with finding the right axles for my m3

[Jake36m3]

Need help with finding the right CV-axles. It’s originally a 320i, but has been fully rebuilt into an M3 (s50b30) by the previous owner. It has the 188mm 3.15 LSD. The current axles on the car measure:
LK: 86mm
D: 27mm
As far as my research goes, this is the measurements for a 325i axle. The only problem with that is that there is 30 teeth at my current hubs and the 325i axles only have 27 teeth. When comparing the CV joints on 325i axles to the ones on the car, the ones on the car are visibly larger. The M3 axles should also have larger joints.
The 3.0 axle measures:
LK: 94mm
D: 27mm
30 teeth at hub?
And the 3.2 axles:
LK: 94mm
D: 38mm
30 teeth at hub?
I have tried to conclude what kind of axles the current ones are, but can’t seem to find any with the measurements and dimensions I have. (LK=86, D=27mm, 30 teeth at hub, larger joints like m3 axles). Would this mean that the previous owner somehow frankensteined different axles together to fit the car?

One of the axles recently snapped at the boot, so I have to find some new ones. Since there is no axles in the dimensions of the current ones, I have to come up with a different solution. I have researched quite a bit, but haven’t found a definitive answer, so I hope you guys can help. Will I be able to swap out the output flanges with the m3 output flanges (LK=94mm)? If I’m able to do that, the m3 axles should bolt right on, right?

As far as I can see, the 3.0 axles aren’t manufactured anymore. Are the 3.0 (33212228156) and 3.2 (33212228513) axles interchangeable?

My plan is as following:
- Buy the m3 output flanges used, as they also aren’t manufactured new anymore?
- buy a new set of non-oem 3.2 axles (33212228513). What brands are the best?
Will my plan work?

I know its a long post, but I appreciate every bit of help I can get

[Greenday694]

Couple years ago I converted my 325is over so I could run the larger stronger M3 axles. Got tired of breaking the other ones.
The conversion was pretty simple. M3 trailing arms, M3 axles, and M3 output flange for the differential. The M3 axles have larger CV joints. Depending on year, they used either the smaller diameter solid axles. Or the larger diameter Hollow axles. Even the smaller diameter solid axles are bigger than the ones from a 325.
Easiest way to tell without measuring, look at the trailing arms. If they're stamped M3, then you have M3 axles. The M3 trailing arms use a larger diameter Hub and bearing assembly. 325 outboard CV joint would spin inside of them. If your output flange outer diameter measures I believe 105 mm, then that is for the non m.
So in conclusion, if you have non M trailing arms and output flanges, then you buy nonM axles.
As far as buying axles, it all depends on how much you want to spend. And how much power you're making. And how you plan to use the car. The cheaper axles will work for a daily driving. If you're making quite a bit of power and you plan on putting it to use, you'll be replacing axles quite a bit.
FYI, the fastest way to break axles even the M axles, is hard launches, sticky tires, on a prep surface. Ask me how I know. [emoji16]

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[Jake36m3]

My trailing arms are stamped with an m so I’m 99% sure I have m3 hubs too. The weird thing is that I have the smaller diameter output flanges on the diff (LK=86mm), but the hub is larger like on the m hubs. I tried to buy and install 325i axles, but as you say, they were too small on the hub (325i had 27 teeth at the hub, but my hubs had 30 teeth). The 325i axles weirdly fit the output flanges.
The 3.0 axles (solid) are discontinued everywhere (both oem and non-oem). Will the 3.2 axles (hollow) fit the 3.0 188mm diff?
I have ordered the m3 output flanges (LK=94mm), so a 3.2 axle should just bolt right up, right?

[Greenday694]

Not sure what the previous owner did. But I guess if he had access to a machine shop, he could have machined down the end of the axle so that the smaller 325 inner CV joint would fit onto the M3 axle with the outer M3 Cv joint.
My suggesting would be, since you have the M3 trailing arms, bearings and hubs, pop in a set of M3 stubs and use the M3 axles.
All the M3 Parts I installed on the rear of my car, were originally from a 97 M3. It was all a direct swap. Of course I replaced all the bushings and bearings before I installed it.

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[Jake36m3]

If anyone is interested or having the same problem as me - I have finally solved the problem! It turns out that the previous owner DID cut up an m3 and 325i axle to weld them together. He probably did this because he wasn’t able to find m3 flanges, as they are really hard to come by.

I sourced the m3 flanges in Portugal and bought the era Benelux m3 3.2 axles. It turns out that the 3.0 and 3.2 m3 axles ARE interchangeable. The m3 flanges popped right into the diff and axles fit great! Now fingers crossed that the era Benelux axles hold up��

[blckstrm]

When I broke an axle I found one used with relatively low mileage for like $50. Brand new are super expensive, so that was a great route to take. If those hold up you're great, but if not, you can used OEM ones for fairly cheap.