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Posted by: bobforman Mar 7 2023, 08:16 PM

Learned today my 2.0 flywheel has been turned at least once. Concerned about doing it again but would like to know the minimum tolerances for the offset (depth of the plate surface and the pressure plate mounting surface). Can't seem to find it in the workshop manual.

Posted by: r_towle Mar 7 2023, 08:30 PM

Dave has a full diagram.
Search here, it’s been posted.

Posted by: r_towle Mar 7 2023, 08:33 PM

http://www.914world.com/bbs2/index.php?showtopic=149714

Posted by: rjames Mar 7 2023, 09:02 PM

It was suggested in that thread (and by the new flywheel I purchased from PP at the time ) that the diagram was for a -6 flywheel. I never got a definitive answer for a type 4 flywheel after creating that post.

Posted by: bobforman Mar 7 2023, 09:05 PM

Thanks much.

Posted by: technicalninja Mar 7 2023, 10:30 PM

A good VW machine shop should know that info and when the flywheel is turned the same amount should have been removed from the PP mounting surface.
This is called a dual or step cut and will be more expensive than a single cut.

I don't have a measurement either but if you can get Eric on the phone he would probably know.

https://www.automotivemachine.com/

This machine shop specialized in VWs first...
I've known Eric since he was 5 years old.
His dad Tom started AM in the 70s I believe.

He now modifies type 1 engines into oil field equipment for the removal of natural gas and contaminates from oil wells.

Ever seen a V8 that 1/2 of it was a compressor?

He did the same basic thing with a type 1.

There is a picture of it under VW parts header on his web site if you're interested.

Posted by: technicalninja Mar 7 2023, 10:49 PM

Just looked at that other thread.

If you are asking about measurement C (disc surface to flywheel bolt mounting surface)
I have a 73 2.0 flywheel that I believe has never been turned and its C measurement is right at 9mm so I'm thinking 9 is what they start out as and not a minimum thickness measurement.

In your shoes I'd call AM anyways.
He's very hard to get on the phone. Leaving a message is usually a requirement.

Posted by: ClayPerrine Mar 8 2023, 06:49 AM

The only difference between a /4 flywheel and a /6 flywheel is the crank mounting surface. They use the exact same clutch disk and pressure plate. So the dimensions for turning a flywheel are the exact same.

Posted by: technicalninja Mar 8 2023, 10:16 AM

That's good info Clay. Thanks!

So, the step between disc surface and pp mounting surface is 22.5mm or "A" in the diagram.

This is the important measurement to get correct.

Many times in the past I've found inaccuracies in published OEM data...

Why would anyone cut the ring gear upper surface?

That diagram shows different values for "B" which is the total thickness of the flywheel.
In my world this figure would never change as I see no need or gain for machining the face of the ring gear, just extra cost as that would be a third cut at the machine shop.

My unmachined 73 flywheel measures 40.4mm for B and the back surface is not flat as shown in the diagram. It has a small chamfer on the outer edge.