M4 380mm brake rotors fits E92 m3 hub?

tdott wrote

Someone needs to try CCBs from an f8x!

F8x CCB front 6 pots / M2 2NH 6 pots on E9x and F3x chassis F8x CCB front 6 pots / M2 2NH 6 pots on E9x and F3x chassis

KevM3UK wrote

also the E92 wheel bearing fits exactly to the m4 spindle, i tried it off the car first then bolted the disc on and caliper, its plug and play with no altering of the track ,the wheels sit exactly the same and i still use my 10mm spacer with no ill affect.

Can you confirm which wheel bearing bolts you used? f8x or e9x?
The mating surface for the bolts look different, flat vs ball seat. But the bolts are different length and different thread pitch, so that has me thinking the e9x bolt has to be used to thread into the e9x wheel bearing on the f80 spindle. But considering this is what is holding the wheel bearing and everything attached to it (calipers, rotor, wheel, etc). I don't know if I want to risk putting a square peg in a round hole if you know what i mean.

I may consider just using f8x wheel bearings as that conversion is possible also.

According to realoem. f80 wheel bearing bolts are shorter (M12X1.25X45) and one time use. e9x is M12X1.5X60-10.9.


EDIT: Actually looking at the wheel bearing part on realoem, it lists 3 different bolts and 1 of them are M12X1.5 so I assume that is the one I gotta use. I was looking at part #4 which is the bolt itself and only one was listed.

Kevin, can you tell us what size the rear spacer washers are? Also, how did you reverse the E9x speed sensors 180 degrees on the F8x spindle? Does your abs still work?

tdott wrote

Can you confirm which wheel bearing bolts you used? f8x or e9x?
The mating surface for the bolts look different, flat vs ball seat. But the bolts are different length and different thread pitch, so that has me thinking the e9x bolt has to be used to thread into the e9x wheel bearing on the f80 spindle. But considering this is what is holding the wheel bearing and everything attached to it (calipers, rotor, wheel, etc). I don't know if I want to risk putting a square peg in a round hole if you know what i mean.

I may consider just using f8x wheel bearings as that conversion is possible also.

According to realoem. f80 wheel bearing bolts are shorter (M12X1.25X45) and one time use. e9x is M12X1.5X60-10.9.


EDIT: Actually looking at the wheel bearing part on realoem, it lists 3 different bolts and 1 of them are M12X1.5 so I assume that is the one I gotta use. I was looking at part #4 which is the bolt itself and only one was listed.

I see the same problem! The E9X hub has a1.5mm thread pitch. The bolts for the E9x hub are flat. As pointed out above (very good observation) the F8x spindle where it receives the hub bolts is round (indented) not flat like the E9x. Also the f8x hub has a 1.25mm thread pitch. I don’t see with the difference in collar shapes and thread pitches that one could interchange hub generations on the newer spindle. It seems a round collar M12x1.5mm bolt would be needed to use the E9x hub on the F8x spindle. I can’t find such a bolt. If someone cannot clarify, I see the only solution being we would need the F8x hub with the F8x spindle. Now parts to do this swap are getting spendy.

Edit: the M4 wheel bearing bolts are M12x1.5 not 1.25 with a round collar. At least the ones I have are.

Socket head bolt? Torx head bolt? Both have circular heads that are smaller diameter than a hex head.

jcl17 wrote

I can’t find such a bolt. If someone cannot clarify, I see the only solution being we would need the F8x hub with the F8x spindle. Now parts to do this swap are getting spendy.

I updated my post adding the screenshot of readoem showing that under the wheel bearing part itself (#3) there are 3 different bolts listed. Where as the wheel bearing bolt itself (#4) is what I was originally looking that.

31206783065 is a M12X1.5X45 bolt with a ball seat that will fit the f80 spindle which is what I think is needed to mount the e9x wheel bearing in the f8x spindle. But I don't have confirmation as yet.

pbonsalb wrote

Socket head bolt? Torx head bolt? Both have circular heads that are smaller diameter than a hex head.

We are referring to the type of bolt mating surfaces.

You can't put an e9x one in the f8x spindle. It will not sit flush.

Interesting bolt!

The mating surface is what is different. Zoom in on the knuckle where the four hub bolts go on the m3 and do the same on the m4 one. Notice one is flat like any normal bolt. The other has a round ball indent like the female conical connection of a wheel lug where the lug nut goes. I wish Kevin would chyme in how he ended up with the project. I’m near certain the hubs are not interchangeable. At least not safely considering the bolt mating surfaces are not interchangeable. Anyhow. I have one m4 hub, one m4 knuckle, and one m4 brake rotor and caliper to experiment on my e93 m3. I’ll let you guys know what I figure out and confirm the hub bolt issue myself Later next week when all arrives.

Oops. My page hadn't updated before I posted. Your pic shows the dilemma well. If you find an m12x1.5mm thread with the ball mating surface let me know.

They make them in lug bolt style, but the head won’t be low profile.

jcl17 wrote

Oops. My page hadn't updated before I posted. Your pic shows the dilemma well. If you find an m12x1.5mm thread with the ball mating surface let me know.

Like I said before:

31206783065 is a M12X1.5X45 bolt with a ball seat that will fit the f80 spindle which is what I think is needed to mount the e9x wheel bearing in the f8x spindle. But I don't have confirmation as yet.

I've done this project. Had same issues missing in topic.
1. Bolts. Because car was in parts had to find solution quick. On hands we had Audi bolts with rounded head witch fit perfect. You can see bolts in pictures but I don't have part number.
2. Abs sensor for DCT. Pull it out rotate 180 deg and mount. Need to make special flusher to hold it in place.




3. Washers to center rear caliper. Use 2 washers for one bolt. 4 washers for caliper.




Final result on Eibach pro kit:

Completed my swap.

Wheel speed sensors were still reading the wrong direction for me at 180. But if I turned it to the outside 15 degrees until it pushes against the spindle then check the live reading it started reading correctly, sorry I didn't take any pics. Maybe I'll try to get some later. The correct direction if you look at the old position is the screw should be pointing towards the outside, not in the down or up position.

31206783065 are the wheel bearing bolts I used.
I only used 1 washer for each rear caliper bolt.

This is a quick mock up of Nostra's picture of how I positioned the sensor. I also tried 180, 90 to the left and both still read in the wheel in the wrong direction according to sensor data of the live stream

Awesome and still working on this

tdott Do you need any washers used for rear calipers or did they bolt straight up to E9X hubs?

Nice work they look clean

DR-JEKL wrote

tdott Do you need any washers used for rear calipers or did they bolt straight up to E9X hubs?

Nice work they look clean

Thanks, I only used 1 washer for each rear caliper bolt.

Visual of the size difference.

tdott wrote

Thanks, I only used 1 washer for each rear caliper bolt.

I tryed one, but it looked not center... I was more satisfied with two washers on bolt. Did you check if it's center?

How you test abs sensor readings?
I did test drive, and after 180 degree rotation downshifts felt smooth again, so I fixed them that way.

The Hall effect sensor "should" work in the original orientation and 180 out of phase as far as my understanding of this goes. Can anyone explain this ?

Nostra wrote

How you test abs sensor readings?
I did test drive, and after 180 degree rotation downshifts felt smooth again, so I fixed them that way.

I checked the wheel sensor readings using an obd2 reader capable of reading the live stream data from the dsc module. I tested in the 180 position and it was still saying it was in the reverse direction when going forward. I then tried 90 to the inside, same thing. It only change when I turned the sensor as much as I could torwards the outside.

Perhaps your car is different, but I confirmed by reading what the car sees from as wheel speed and direction.