924Board.org

[Motorheadmike]

I just aquired a lightweight flywheel for my 931. What can I do (if anything) to make it work with the crank sensor.


Thanks, Mike
1981 931 series 2

[Motorheadmike]

I guess I should be more specific. It is the tone ring(crank sensor pickup ring) on the flywheel that I am confussed about. The orig. flywheel has a tone ring, The replacment lightwieght one(fidanza) doesnt. The Fidanza tech guys say that the tone ring will come off of my origonal flywheel. Is this true? If so, How?

Thanks again, Mike

1981 931 series 2

[John Brown]

Heat. It's an interference fit. I believe the turbo supplement has a procedure.
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John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

[Motorheadmike]

looks one piece to me. but I will try to heat it and see what happens, old flywheel is tost anyway. I guess it is like installing a ring gear on older domestic flywheels.

[Motorheadmike]

definantly one piece. man did I get that sucker hot. Did they make two differnt flywheels for the 81 and later cars? does anyone have the turbo suplament book to verify I that tone ring comes off? I realy want to get this thing together so I can drive. I gues I will just buy a used replacement and try to return this cool lightwight alluminium one.


Thanks everybody, Mike

1981 931[/quote]

[Motorheadmike]

definantly one piece. man did I get that sucker hot. Did they make two differnt flywheels for the 81 and later cars? does anyone have the turbo suplament book to verify I that tone ring comes off? I realy want to get this thing together so I can drive. I gues I will just buy a used replacement and try to return this cool lightwight alluminium one.


Thanks everybody, Mike

1981 931

[Smoothie]

There were 3 different flywheels. One for the 924NA with removable ring gear. One for the -'80 931 with no starter ring gear (since the starter goes in through the back, the gear is on the clutch pressure plate). -And the '81-up 931 got a flywheel with teeth that as far as I can tell from the parts list, aren't removable from the flywheel (the ring gear for the 924NA is listed as a seperate part, while there is no seperate listing for the '81-up 931's flywheel teeth). Your only option for an '81-up 931 apparently is the OE series 2 931 flywheel.
Some misc. details on it - it has 100 teeth and located at one of them, about opposite the TDC mark, is a "sintered metal insert" that triggers the crank sensor. (I'd imagine the 100 teeth are there for a reason and may have some affect on the crank sensor as well, but the sintered metal insert is apparently the main trigger-er.) The manual talks about the flywheel-to-crankshaft being a press fit and says to heat the flywheel to 140°F for installation of the '81-up 931, but doesn't say anything about heating a ring gear or about it being a seperate piece.
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox