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  Clutch and Flywheel Instructions and Information

WARNING!! Cast iron flywheels can be moderately lightened for STREET USE ONLY. Some excess can be safely removed, but the limit should be around 5 pounds. Auto manufacturers make their flywheels thick and heavy to overcompensate for the porosity and brittleness of cast iron material. Stress or vibration can cause cracking and failure of lightened cast iron flywheels. (**SEE THIS**!)

 
Typical MC/Bias bar/Pedal installation in a fendered car - top mounted pedals
(Click for full size images)
[For more information about MOUNTING top pedals in a fendered car,
see the instructions in the Brake Section]


Note Bias Bar between the 2 large brake M/Cs
 

 
Adjusting Clutch Free Travel - SMI modification

1.) Bend the first 1/2 inch of the tab end of the bracket to a 45 degree angle
2.) Feed one closed end of the spring through the hole in the bracket. ( This keeps it captive so you will not need to worry about losing it.)

3.) Remove the slave cylinder from it's bore in the bell housing without removing the hydraulic line if possible. (You may want to pop the piston out of the slave cylinder and remove the spring that does not need to be there.)
4.) The return spring bracket slips over the cylindrical body of the clutch slave cylinder.
5.) Install the slave cylinder with the flat side of the bracket facing the block. This feature keeps the bracket from rotating.
6.) The other closed end of the spring needs to be modified before it can be hooked onto the hole in the clutch release lever arm. Snip off 45 degrees of the closed end to create this hook
7.) Using a small set of needle nose pliers, slip the spring hook into the lever arm hole.


Slave cylinder mounted to bellhousing 

  Stop against bellhousing

ADJUSTABLE FT STOP INSTALLATION INSTRUCTIONS
1.) Material required: one 6X1.0mm nut and machine bolt 24mm long.
2.) Tools needed: Drill, cutting oil, carbide 5mm bit and 6x1.0mm tap. (This arm is about 45 Rockwell, so nothing but a carbide bit is going to work. A 3/16" concrete bit will work in a pinch.)
3.) With the release bearing lever arm on the bench, measure and mark 2.5" from the center of the spring hole.
4.) Through drill a 5mm ( 3/16") hole at this spot. Use cutting oil or the drill will burn.
5.) Tap the hole being careful not to break the tap in this hard material. Also be careful not to tap it out all the way. You want the threads to be tight enough to create a little resistance screwing in the 6mm stop screw.
6.) Before installing the stop bolt, file off any numbers on the top so that the flat surface is smooth and will not eat into the aluminum bell housing.
7.) Next, file the forward side of the clutch window flat where it will contact the stop screw head.
8.) Install the jam nut on the 6mm machine screw so that about 1/2 inch of screw is proud of the lever arm.
9.) Install the lever arm in the bell housing.
10.) With the gearbox and clutch installed, adjust the travel. The gap you set at the stop will be increased by a factor of two at the release bearing.

FREE TRAVEL The consideration here is that the release bearing not ride on the pressure plate except during disengagement activity. With both Sachs and Tilton clutches, set the clearance at STOP to about .020". The arm ratio is 2:1 so the actual clearance at the release bearing is .040". The important consideration with a Tilton clutch is that the stroke, or total depression of the diaphragm spring be limited .700". Over-stroking even once may damage the clutch. All Alfas have a pedal stop adjustment. All of our Tilton pedal assemblies have this feature. Set the stop just beyond the point of release.


Interior of bellhousing showing the clutch pivot knob.
  
**SMI Store**

TESTIMONIAL .....7.25" TILTON RALLY CLUTCH SET UP
 

Two years ago, this customer bought a complete 7.25" SM flywheel with Tilton Rally pressure plate, our sprung four puck disc and release bearing. This is our email exchange with Jerry A.

Hi Paul, Quite happy with the 7.25 flywheel/sprung rally disk. Trying to figure where I am in the wear cycle...now measures about .290" or so, note the wear limit is .280, but don't know where it started. What is the thickness new?

Thanks, Jerry A

SM Reply: Our new rally discs start out at about .300" thickness. We use two different compounds to balance wear and smooth engagement. The hard compound is mounted on the flywheel side where most of the wear occurs. Great to hear it is working as anticipated.

Paul,

Wow!! If the disc started at .300 and I'm now at .290, I should have another 2 years to go! I'll be relining the disc in a couple years. It works, and I'm happy with it. Amazing the abuse this stuff will take with a few thousands wear. Not that I abuse stuff.

Thanks, Jerry A.

 

  

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