Dennis wrote:

I'm putting in a new Ford flywheel M-6375-A302B to address a balance issue.  I'm using kit number M-6397-A302 that includes the dowels.  As best I can tell, there is a few thousandths press fit between the parts. Moderate tapping with a brass hammer hasn't gotten the pins in.  Is this normal, am I using the wrong method, or is one of the parts wrong?  According to my Mitutoyo calipers, the pins measure 0.313, and a 0.3095 drill shank fits into the hole easily.  The hole is somewhere in between those measurements.   

 
There needs to be an interference fit so the pins don't fall out.  You have .0035 interference for a nice snug press fit.  You're good.

A light press fit on something that small wold only be a couple thousandths, and that's all that fit should be.  The dowels are just for locating the pressure plate during installation.  Once its torqued down the bolts do the job.  The pins are made such that they can't fall out once the pressure plate is installed (flywheel side is larger in diameter than the hole in the pressure plate).  What you describe is not a light press fit IMO.  The pin is 0.0035" bigger than the hole.  The press fit for a bearing or race is about that tight, and those are significantly larger than a flywheel dowel.  An interference fit tends to increase as the parts get bigger, so on something like those dowels I would only expect maybe 0.002" interference, whereas on a differential side bearing it might be more like 0.003"-0.005" depending on the size of the bearing.   

All that said, the flywheel is double drilled for both a diaphragm and Long style pressure plate.  The diaphragm pattern will use the 8mm bolts in the kit you have, but the Long style uses a 5/16" bolt.  I would think there are also two sets of dowel pin holes.  So, I would try this: thread the bolts from the kit into the appropriate holes in the flyhweel and then see which dowel pin holes correspond to that pattern, and see if the issue you are having still exists.  They may have made the dowel pin holes different sizes to prevent mismatching the two different pressure plate styles with the bolts and dowel pin holes.  

Obviously I'm assuming you are using a late model diaphragm clutch kit (Fox era) that uses the metric hardware.  

Last edited by TKOPerformance (Today 10:52 AM)

I have a Mcleod flywheel and drove the pins in with a hammer, without a lot of force, w/o shrinking the pins. 

I'm pretty sure I have the same flywheel and just tapped the pins in with a brass hammer.  

Thanks guys.  I went ahead and tapped/beat them in with the brass hammer.  They are definitely tighter fitting than I expected.  Since the flywheel is on the engine, it became a nice bell so I'm officially deaf now from the ringing.