Clutch Question

[harrywt]

The friction plate compresses about 10/1000" , 0.010"

I left the paper with the measurements back in my shop of course. I measured both the new and old friction plates while clamped in a c clamp and the 8.13mm spacer comes out at about halfway as I suspected

remember the disk will compress quite a bit when under the load of the pp.
The spacer spec is closer to the compressed thickness.

 

[Robert Kenney]

The finger height uses the flywheels machined friction surface as the datum, not the middle where the bolts go. Looks like you have the caliper on the middle surface in your photo. That will help your measurement.

 

[harrywt]

Thanks Robert, I'm glad someone is watching the posts. If you look carefully above you will see that I know about the point where I should be measuring.

The distance from the flywheel bolt surface to the flywheel engaging surface was measured as 17mm, I added this to the 50.8mm specified distance

the finger height uses the flywheels machined friction surface as the datum, not the middle where the bolts go. Looks like you have the caliper on the middle surface in your photo. That will help your measurement.

 

[harrywt]

ok. No one is sending me the dimension I need to set up the clutch. This would be the distance from the top of the screw heads to the flywheel face while a spacer is in place instead of a pressure plate and the pressure plate is bolted to the flywheel.

I measured the old bolts to get a sense of the original setup distance and attempted to match it. Notice that the space from jam nut to bolt head is variable, I checked that the clutch fingers have a similar variation. I gave the lower finger the larger distance.

Then I made sure that all bolt heads are co planar so that the throw out bearing makes even contact.

So next weekend she's going back in there come hell or high water. I have sent a second email to mid-america clutch who sell this clutch. Also the IHPA guys have asked their clutch rebuilders to give them a call regarding this but no answer yet.

 

[harrywt]

So I have installed the flywheel, clutch and transmission! Thanks to IHPA for trying to get info from the clutch rebuilder!!

I was not able to get a definitive answer to the dimension for setting the clutch finger screws. If you have followed this thread and the "t19 install in korea" thread you May have noticed that I have been building up a picture of what the adjustment accomplishes.

Of course the most important thing is to have the throwout bearing contact evenly every time you press on the clutch pedal. That's the easy part.

At the end of the day it is a matter of making sure that you can adjust your clutch pedal over the life of the friction plate. We all know the rod that goes from up by the steering rod and down through the floor to the relay lever. It is threaded on either end but with opposite handedness, same as a tie rod, same as the screen door save you buy at the home depot.

When your friction plate is new, the rod should be adjusted to its shortest length and as the friction plate wears you lengthen it gradually to have the clutch engagement point in the pedal travel stay in the same place.

Now there are three levers on the way to the throwout bearing, 1) the clutch pedal, 2) the relay arm and 3) the throwout arm in the bell housing. We need all of them because the springs in the clutch are badass strong. I couldn't budge one clutch finger while placing all 240lbs of harry against it.

With three different levers it is difficult to calculate how much swing of the clutch pedal translates to movement of the throwout bearing. So we have a table in a shop manual to look up how far the clutch fingers should be from the flywheel face when the clutch is ready to install. In fact 99% of us let the clutch rebuilder do it for us.

What I did was take the old adjuster bolt that was assembled to the highest clutch finger and measured the distance from the bottom of the jam nut to the top of the head. I then matched the new adjusting bolt to this dimension. I installed this new bolt and used it as a fiducial. I then made sure that all of the bolt heads were coplanar with a digital level and an old bearing race. It was a bit tricky, I should have done it on an assembly table. I tried to level the flywheel but I found it easier to get the flywheel very steady on the table and then match the bolts to the flywheel. If the flywheel was at 0.9degrees then I made that bolt axis 0.9degrees. This definitely introduces some error but I decided to accept it.

So now some pics and I have to get back to some "honey do" stuff, more later.