KJ Jones
February 4, 2014
The top disc (sprung hub) sits atop the floater. GTR uses a repurposed 10-spline input shaft as a clutch-alignment tool to ensure the transmission can be reinstalled without much heavy effort.
The pressure plate/cover is the final piece of the Ram twin-disc clutch package. Eddie confirms the previously made alignment marks (small references on the cover and flywheel that Eddie made before) all match before calling the procedure done.
Setting the air gap (between the face of the bearing and the pressure plate’s fingers) really is the only part of the operation that can be somewhat confusing, as detailed calculations must be made to ensure air gap is sufficient. The first measurement (A) is taken at the engine and equals the amount of crankshaft flange that pokes out of the engine block. Next, with the throw-out bearing compressed, Ricardo uses a straight edge and a vernier caliper to measure the depth from the bearing face to the face of the bellhousing. This is measurement B. Finally, measurement C is the distance from the tip of the clutch fingers to the flywheel, better known as the setup height.
Setting the air gap (between the face of the bearing and the pressure plate’s fingers) really is the only part of the operation that can be somewhat confusing, as detailed calculations must be made to ensure air gap is sufficient. The first measurement (A) is taken at the engine and equals the amount of crankshaft flange that pokes out of the engine block. Next, with the throw-out bearing compressed, Ricardo uses a straight edge and a vernier caliper to measure the depth from the bearing face to the face of the bellhousing. This is measurement B. Finally, measurement C is the distance from the tip of the clutch fingers to the flywheel, better known as the setup height.
Here is the Ram hydraulic clutch-release (throw-out) bearing/slave-cylinder assembly. The bearing’s adjustability and increased travel (over the factory hydraulic piece) helps ensure that fingers on the pressure plate do not make contact with the bearing when the clutch is engaged.
After removing the stock hard line that feeds the throw-out bearing, Eddie installs Ram’s new braided line, which pops right into the master cylinder at the firewall using the factory fitting. With the exception of road-testing Ken’s ’Stang and then driving roughly 500 miles to properly seat the new clutch, making this connection basically completes the dual-disc clutch install. While the Force 10.5-inch setup will support approximately 1,100 lb-ft of torque, its top disc's sprung hub and the hydraulic bearing provide quiet smoothness and pedal effort similar to that of the original equipment.
The clutch-release bearing slips over a collar that bolts to the transmission. Notice the two AN -3 fittings that Eddie installed in the bearing’s slave cylinder? The fittings support braided line that routes hydraulic fluid into and out of the cylinder, and in turn moves the bearing’s piston back and forth.
Here is the assortment of steel shims that are included with the clutch system. The shims are used for adjusting the depth of the clutch-release bearing and fine-tuning the air gap. After measurements are taken, measurement A is added to measurement C, and then the sum of this equation is subtracted from measurement B. The amount of air gap typically should be set at 0.1500- to 0.200-inch. This routine (removing and installing the transmission and re-measuring) definitely will become repetitive if you miscalculate, so it’s important to take your time and be careful when recording this data.
DOT 3 brake fluid is used for the Ram hydraulic throw-out bearing. The AN -3 braided line on the right is the actual fluid feed for this system; the line on the left is the bleeder circuit.