I am manual swapping my 528, posted about it before, and when researching the speed and reference sensors I noticed the flywheel needs a pin for the reference sensor to play off of. However I don't see that pin on my flywheel nor do I see it on the diagram for it on real OEM.
#8 is a dowel pin and there are three of them for the clutch to align. For manuals do the reference sensors play off of the dowel pins or am I missing something? Looking at pics of other flywheels I don't see anything save the dowels that the reference sensor could play off of
1st 5er wrote: Dec 29, 2024 9:08 PM
Yes.
I'm not aware of a separate # being that it's an integral part of the flywheel and specific to each application.
I might try to weld on the piece from the flex plate from when it was an automatic.
Is there any specifics on how large the piece should be, or is there wiggle room? Piece I have is bigger than the piece welded on in the image above
Whats it actually using the sensor for, just engine speed, or does it need an accurate timing reference for something? If its batch fire and not driving the ignition I'd assume its just speed. At that point its not super critical, just make sure its well attached. Don't want that thing flying off at 5 grand.
gadget73 wrote: Dec 31, 2024 9:43 AM
Whats it actually using the sensor for, just engine speed, or does it need an accurate timing reference for something? If its batch fire and not driving the ignition I'd assume its just speed. At that point its not super critical, just make sure its well attached. Don't want that thing flying off at 5 grand.
The sensor is for ignition timing so it's got to be pretty close. However I don't know how much clearance there is between the tab and the sensor. I've always thought if I had one fail on a M/T car I'd try tapping a small hole and putting a small bolt in there. With red locktite. Never done it, but that's what I'd do.
Does anyone have the correct position for the reference sensor block. I am in the same predicament and need to weld a tab on, but need the correct positioning. Either dimensions or a tracing..... Thanks
Tone1633 wrote: Jan 02, 2025 4:06 PM
Does anyone have the correct position for the reference sensor block. I am in the same predicament and need to weld a tab on, but need the correct positioning. Either dimensions or a tracing..... Thanks
A/T or M/T? I can probably measure it, but it might be a few days. I measured one long ago for a guy in Australia, but gawd, that must have been 20 years ago and I doubt I can find the info anymore. Ping me if I don't report in a few days, I'm not a flake but I am entirely capable of forgetting.
I went down this route when I fitted a manual gearbox to my 525e Auto. I used an E21 flywheel, but for the life of me icant find/remember how I worked the tab position out.
All I remember is thinking that the car was a bit gutless and the whole project was a waste of time.
I would highly recommend fitting motronic M1.3, which dosent use the flywheel tab, rather a timing wheel on the front of the engine. You will want to do this anyway when you fit a 731 head on it anyway.
OK, took a reminder but I finally dug it out and took measurements and pictures. The image a few posts up does look like what I remember, but not what I have, which I think came off an '82, E24. But it was probably at least 15 years ago I pulled it so I might have the exact car wrong. But it is a lightweight motronic flywheel. Images didn't come out as clear as I would have liked, wow, like that's a first, but hopefully usable. And I have the direction of the cutout by the tab facing in the wrong direction, look at the pic to be clear on that, not my scribbling. And feel free to ask more questions. Also, especially to the OP, don't forget the stiffener/spacer on the bolts and the bolts themselves are a different length than the ones on Autos.
Mike W." wrote: Jan 08, 2025 1:14 AM
OK, took a reminder but I finally dug it out and took measurements and pictures. The image a few posts up does look like what I remember, but not what I have, which I think came off an '82, E24. But it was probably at least 15 years ago I pulled it so I might have the exact car wrong. But it is a lightweight motronic flywheel. Images didn't come out as clear as I would have liked, wow, like that's a first, but hopefully usable. And I have the direction of the cutout by the tab facing in the wrong direction, look at the pic to be clear on that, not my scribbling. And feel free to ask more questions. Also, especially to the OP, don't forget the stiffener/spacer on the bolts and the bolts themselves are a different length than the ones on Autos.
Is the z location a specific place on the flywheel or can I weld the thing on anywhere on the side? I don't see how it would matter or it would tell when it's just spinning with the engine, and for all I know when mounting the flywheel all that matters is that the bolt holes line up, right?
Is the z location a specific place on the flywheel or can I weld the thing on anywhere on the side? I don't see how it would matter or it would tell when it's just spinning with the engine, and for all I know when mounting the flywheel all that matters is that the bolt holes line up, right?
Z is emphatically a specific location and the tab has to be pretty much exactly in the correct location. Open this pic in a new tab to view it full size and you can see the Z marked on the side or the flywheel. The dowel (kind of a sleeve which only fits in one bolthole on both the crankshaft and the flywheel) locates the flywheel in the correct location on the crankshaft, so that's a fixed point, then you need the tab in the correct location so the ECU knows where to fire the ignition. Say 1/8 of an inch wouldn't make much difference, but that's about as far off as you want, it's got to be pretty damn close to perfect. Again, zoom in on the pic and you can see the mark and the Z. Also the OT mark, but you don't really need it.
Z is emphatically a specific location and the tab has to be pretty much exactly in the correct location. Open this pic in a new tab to view it full size and you can see the Z marked on the side or the flywheel. The dowel (kind of a sleeve which only fits in one bolthole on both the crankshaft and the flywheel) locates the flywheel in the correct location on the crankshaft, so that's a fixed point, then you need the tab in the correct location so the ECU knows where to fire the ignition. Say 1/8 of an inch wouldn't make much difference, but that's about as far off as you want, it's got to be pretty damn close to perfect. Again, zoom in on the pic and you can see the mark and the Z. Also the OT mark, but you don't really need it.
There is no notched line like that on my flywheel. Your flywheel is for an m20, correct?
There is no notched line like that on my flywheel. Your flywheel is for an m20, correct?
Arggg. No, M30.
Half you, half me. I should have checked, 528's were mostly here in the US 528e's, but there are also a lot of gray market 528i's here. Oh well.
No worries. You know any sources I can use to find out where to weld it? Or should I not chance it and just shell out the money for a new flywheel with one?
