Lets talk axle tech. Pics, info, expereinces, etc

[Gmfwd]

I am making this thread to spread and gather axle information for these cars.

I have a track and street e36 that I beat the crap out of. 360wtq 370ish hp conservative.

Heres my issue: I break a crap ton of axles. Actually broke 12 this year. I am very rough with the car.


I run a non-m rear setup. Why dont you go m3 you say? Well I have invested a lot in my dual wilwood e-brake setup and I would prefer to retain in... But I may end up swapping anyway. My goal here is to investigate if there is any way to build stronger non-m axles for myself and anyone else interested.


So lets nerd out a little:
Heres a e36 inner CV. Its 100mm diameter 6 bolt. This CV is not proprietary to BMW, it is actually from a VW Bus, just not as thick (less plunge in and out)


It uses 20mm balls


Its 26mm thick


It takes a 25 spline axle shaft
This is considered a type 2 CV or T2. Very common in the VW/Audi/Porsche cars, and dunebuggies based from them.

My original intent was to simply put stronger, off the shelf axles in these CV's and call it a day, afterall, the joint never fails for me, its always the shaft.

There are 3 types of e36 axle for medium case cars
Typical 328, 325, and bastard 328. Below you see 2 typical 328 axles and one bastard 328. I don't have any 325 axles handy but they are skinnier a are not gun drilled IIRC, making them the strongest.


These tubular axles fail very easy for me. The bastard axle breaks more like a 325 axle as they are less hollow. They almost look machined when they snap off.


Like I said before, these axles are all 25 spline, measuring the OD shows:


Inner hole for the 328 type is



Sooo... back to my origional plan of buying axles and putting them in... Well all of the aftermarket axles I can find are 28 spline or 31 spline. Swayaway.com is a good supplier but there are many more offing off the shelf options of any length.

So I either need to find 28 spline "stars" for these CV's or I need to abandon these cv's all together.

More on this soon

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Here is a m3 CV:


It measures 108mm. It is known as a 930 CV, pretty much the small block chevy of the CV world. It has tons of aftermarket options and is stronger than the T2 right out of the box.

It uses a magical 28 Spline axle


However you notice this axle is really drilled out. Not sure if all M axles are like this or not.


This is for sure a strong axle, but is it strong enough for the stupid things I do? Maybe maybe not.

The cool thing is that you can buy a set of chromoly axles for M cv's and build yourself some really strong stuff for cheap.

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Its common knowledge that the m3 axle wont fit the normal e36 hub.


So heres my potential options:

1. Get someone to cut custom 25 spline axle shafts for stock CV's

2. Get custom "stars" for the stock CV's to use off the shelf 28 spline axles

3. Modify my hub to take a m3 axle

4. Swap entire rear trailing arms and re-make my wilwood hydro setup

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Option 1:
Could be pricy. And what if I do reach the limit of these nonM cv's?

Option 2:
Less expensive as option 1. I can buy a T2 CV with 28 spline off the shelf for VW, the only custom/unknown is will the star fit the outer CV...

Option 3:
The m3 hub is only 3mm thicker diameter then my wheel bearing. I already have m3 diff flanges. Maybe I have stock hubs turned, press them back in, and slap it together?

Does anyone have a e34 axle handy? Do they use a 100mm CV? There wheel bearing has the same ID as e36. Maybe there stub and flange would fit and then I could have a bolt on CV at the axle and at the diff??

I have looked into e46 options. 325/328 uses the 100mm CV. I have not had one apart to see if there 25 or 28 spline, 28 spline would be awesome!

e46 330 uses different CV's and a axle stub comparable to e36 m3 so same case there...

4WD chev s10 and some f150 use a 27 spline axle hub. Maybe one of their stub shafts is more suitable for my needs... gonna have to tear into one and find out.

Option 4:
Starting to look more reasonable. I just wanted to fully explore all other options before going down that path.


So sorry for the huge brain dump. Please discuss any info or experiences you have. Maybe we can all gain something from this.

[E36 HateR]

Get a bearing with the outer diameter of a non M wheel bearing and the inner dianeter of an e36 m3 splined hub, press in, swap axles, and go.

[Gmfwd]

That would be 45mm ID and 75MM OD

Ive been looking for that for a while. I cant seem to find anything that is wheel bearing duty, but that doesnt mean it doesnt exist

[pbonsalb]

What are you doing to break the axles?

[Fender13Bender]

Put in M3 stuff.

Done

[Gmfwd]

What are you doing to break the axles?

Running a welded diff, 3.91. Many hard shifts and clutch kicks with grippy tires and heavy ass wheels on the street.

Ive only broken 2 or 3 at the track.

The street is much harsher.

[pbonsalb]

Maybe the welded diff is the culprit. Getting axle hop?

Not many break M3 axles. That would be the way I would go even if I had to change a bunch of other stuff. Maybe look into machining the trailing arms instead.

[Gmfwd]

I have never broken a axle with the LSD in it. Unfortunatly it only sees a few hpde events per year with the LSD in and minimal street time.

e30 guys do you have this problem? They use pretty similar axles

[pbonsalb]

Could you make do with a 4 clutch conversion for 60% lock part of the time (during slippage) instead of 100% all the time? Seems like the welded diff is a problem causer with your driving. Usually people with enough power and traction to break axles are breaking 188mm diff gears, front diff bolts, stock driveshafts, and 188 mm diff output shafts. Seems odd you are breaking only axles.

Wheel hop can break stuff, but can be reduced with stiffer diff and subframe bushings. You did not specify what tires you are running -- if they are not R compound, they don't have the stick to be an issue.

May be that if you fix the axle issue, the breakage will just move to the next weak link in the chain, so think ahead and make sure that however you address the axles is compatible with the next likely upgrade.

[iRodD]

M3 everything. 210 diff. Done.

[whoshaunq]

Broke non-m axles left and right
swapped to m3 rear everything, stopped breaking axles.

M3 everything. 210 diff. Done.

this.

[Butters Stoch]

I have dissected 328/325 axles to see if there was a way to beef up. Your best bet is not mess with it, stop wasting money, get the m3 trailing arms and 210mm diff.

[cj.surr]

That would be 45mm ID and 75MM OD

Ive been looking for that for a while. I cant seem to find anything that is wheel bearing duty, but that doesnt mean it doesnt exist

If you can find a wheel bearing with a smaller OD or larger ID, you could always turn a sleeve spacer bushing to fit it.

[Butters Stoch]

Not sure the m3 outer joint will fit the trailing arm of a 325/328. Meaning the ABS sensor and ring.

[Jaze]

I love how you guys throw around "get a 210 diff" like they are laying in junkyards like e36 diffs.

[Butters Stoch]

I love how you guys throw around "get a 210 diff" like they are laying in junkyards like e36 diffs.

Pretty dry out there. Gotta dig deap. But at the same time, I don't see any WTB threads either.

[autowa]

Pretty dry out there. Gotta dig deap. But at the same time, I don't see any WTB threads either.

Will the internal guts of a e46 m3 diff (210) fit in a 750 non lsd pumpkin?

[pbonsalb]

Some of the experts like waganstyle are down on the E46M3 variable diff for long term reliability reasons. But I am pretty sure the guts will swap to another 210mm case.

[autowa]

Some of the experts like waganstyle are down on the E46M3 variable diff for long term reliability reasons. But I am pretty sure the guts will swap to another 210mm case.

Max psi doesn't seem to have any issues with their house e46 with nice numbers. Im pretty sure theybrun stock diff.... I have one sitting here i cant unload so I'm looking in to this since the 750il are hard to come by especially here in Canada.

[E36 HateR]

If you can find a wheel bearing with a smaller OD or larger ID, you could always turn a sleeve spacer bushing to fit it.

Or just shave off 3mm diameter on the m3 hub and press into 328 bearings.

[Butters Stoch]

You can NOT put m3 axles into 328/325 trailing arms. Doesn't matter what you do with the hubs or the bearings. They won't fit the back end. The axle will be hitting the ABS sensor and also hitting the parking brake cable. The M3 outer joints are physically bigger.

[Butters Stoch]

M3 on left, weak sauce 325/328 on right.

[Gmfwd]

Good point butters. I dont have abs sensors but I do have a parking brake still. I never considered back side clearance like that...

[Butters Stoch]

Good point butters. I dont have abs sensors but I do have a parking brake still. I never considered back side clearance like that...

They won't fit. I have a 328 trailing arm next to a m3, just looked, no way will you get it in.

[Gmfwd]

just looked, no way will you get it in.

Story of my life...

So I like the 210mm diff upgrade. A welded 3.64 would do me real good for the tracks I run. Would also eliminate breaking diff covers and diff flanges.

We know that 210 uses M3 style CV on the inside. I guess its safe to assume a outer e32 CV is also of comparable size...



e32 stub flange fits e36 bearing according to realoem here:



So it could be possible, assuming e32 axle is close enough in length, and the stub shaft fits the e36 trailing arm, that these parts could possibly work together in a non-m e36.

I have a spare trailing arm. I should get out to a yard and pull these parts and try it. Maybe, just maybe there is a solution here.