Flywheels - Interchangeability

dj_efk

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Word from my workshop: My flywheel is at the end of it’s life due to deep scoring on the clutch friction surface, I need to find a replacement.

From RealOEM, I see there were two versions: D=240 X 27 (part no. 11221270286) and D=240 X 33 (part no. 11221706577) - I assume the difference of 6mm is down to the thickness of the flywheel (?).

I may be Interpreting what it’s saying incorrectly, however it seems to suggest the latter (thicker?) part superseded the former - hence they are interchangeable (and hence the clutch parts etc. will fit either).


Any thoughts welcome here, as otherwise the part I am assuming is fitted to my 69 2800cs (240x27 - I can get the workshop to measure it) is going to be very scarce!

On the other hand, if they are indeed interchangeable and hence I can use the 240x33 version then that’s a little easy, as this was fitted to some 2.8 and 3.5 5 cars E12/E28/E23/E24 built before Oct 84, some E32s build before Dec 87 and also some E34s built before April 88 - BUT my question would then be this: Wouldn’t the swap affect the clutch biting point, as the geometry of the actuating mechanism will change?

Thanks
 
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Honolulu

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The realoem link illustrates the flywheel for an auto trans car, which yours seems not to be. I assume there isn't another diagram for manual trans cars, since such need not be illustrated. The fiche isn't an assembly diagram, just a sketch of the rough positions of various parts, with p/n's.

The geometry may not change, since most clutch components are bolted to the flywheel. I wonder if the clutch slave was mounted differently though, or one version used a longer pushrod. Some diving into the fiche may reveal that.
 

dj_efk

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Just looked at all the clutch mechanism pages for the car and can’t see any such variation so I assume there is none.
 

pat cooks

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The clutch slave has a long travel and can take up the difference, very early cars used a ZF manual gearbox, only ever seen one, not very nice gearchange and no parts available, later cars from 1970? used a four speed getrag with circlip mounted slave cylinder and a different release arm, later cars, 1974? used a bolt on slave with a different clutch arm and pivot point on the opposite side of the bell housing, I seem to recall that the early pivot was steel and pushed into the front of the gearbox with a clearance hole in the bell housing, later was a plastic pivot pushed into the bell housing, all are interchangeable with a bit of thought and maybe access to a 4" grinder, there are also different style and lengths of release bearings, needs careful assembly and a good idea what looks right regarding angles, travel etc. all above from memory, beware........
 

dj_efk

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Pat,
My car was built in March 69 so is indeed a very early car with the ZF box. Gear change is actually quite nice and precise (to me anyway)

That said, I’m now installing an E12 528i 5 speed in it, so given the the clutch kit is matched to this rather than as per original spec, I probably want a thick version of the flywheel.

Have you got one you can let go of with a good friction surface for the clutch?

Dave
 
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dj_efk

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Update: I’ve found a source who can supply an E28 flywheel but I feel the price he is asking is poor value. Should anyone in the UK or EU have one they can supply me at a reasonable price, please PM.
 
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