Installation Information

Here is some advice for those of you who are looking to install a Helix Clutch and Flywheel kit for the first time.
It has been written in a narrow format, in order to be viewed on a smartphone:


Racing Clutches

Mounting Bolt Kits

There are 2 preferred methods of bolting the clutch and flywheel kit together:

  • High quality socket head cap screws ( min tensile 10.9 ) diameter M8 x 1.25 located through the cover assembly and screwed directly into the drilled and tapped flywheel:
    • In using this method it is important that a counter bore is used to ensure the shear load through the screw is across the full shank diameter and NOT the thread.
    • This method is much faster and therefore lower cost to produce, so is very common. 
  • High quality bolts passing through from the rear of the flywheel:
    • These need to be a close tolerance push fit through the flywheel with a locating spigot machined on the rear of the flywheel to prevent rotation of the bolts / mounting studs
    • This method is the most secure way of bolting the clutch to the flywheel, because it does not put any forces through the threads, however, this method can be more expensive as the flywheel needs to be designed for this fitment type. 
    • This method is our preferred method of fitment; please find a set of fitting instructions below. 


Fitting Instructions:

If you would like to check any clutch or flywheel dimensions, such as: Clutch weights,
torque capacities, release bearing sizes, part numbers or Cover to flywheel bolt options.
Please go online to
To download our racing clutch catalogue which can be downloaded as a PDF document. 

1) Remove the Parts from the packaging, the kit usually includes.

 1 x Cover Assembly
 1 to 3 Driven Plate(s)
 1 x Release Bearing
 6 x Flywheel K-Nuts
 6 x washers
 6 x 5/16UNF Bolts
 1 x Flywheel

2) Wipe the flywheel friction face and clutch friction face(s) with spirit.
     This is to remove the light coating of rust prevention oil.

3) If needed, trial fit the assembly in order to familiarise yourself with racing clutches.
    (However do not use the K-nuts and bolts as they are single use.)

4) Take the 6 long, gold coloured Cover Bolts
    push them through the 6 x 8mm holes in the flywheel from behind.
   The heads of the hex bolts will seat against a lip machined into the flywheel.

5) Bolt the flywheel to the crank. Use Standard Bolts unless crank bolts have been supplied.
    Torque to Manufacturers specification.
    If Loctite is to be used, we recommend 243 or 270. (Follow instructions on tube.)

6) Place driven plate(s) onto friction face(s) of the cover assembly.
    If driven plate uses a sprung centre, ensure the raised spring windows face towards the gearbox, unless otherwise labelled.

7) When looking at the side of the cover assembly, red marks should be seen.
     Ensure that the red paint on the side of the inter-plates line up with
     the red paint on the leg of the racing cover assembly.

8) Place the clutch kit onto the flywheel bolts.  
    Use a clutch alignment tool to centre the driven plate(s) within the assembly.
    Place a washer and a K-Nut onto each bolt.

9) Tighten up the K-nuts onto the bolts, working in a diagonally opposite pattern,
     using a 3/8 socket 3 turns at a time until tight.
     Torque the K-nuts to 22Nm, using a calibrated torque wrench.

10) Check that the legs of the Cover assembly are sitting flat against the face of the flywheel
      and the clutch fingers are equi-distant from the splines in the centre of the driven plate.

11) If a new release bearing is supplied it should fit onto the release arm,
      with an identical type of fitment to that of the standard bearing.

12) You should now be ready to bolt your gearbox back up.
      Ensuring that the first motion shaft in the gearbox is correctly support at its flywheel end.



Concentric slave cylinder

When fitting a C.S.C. conversion with either a historic car or racing clutch, a 6mm thick Top Pad (T.P) should be used.
This fits against the fingers of the clutch and allows the flat face of the bearing to press against it. 


When replacing the old CSC do not compress the new unit prior to fitment as compressing a dry, unfitted CSC can damage the internal seals. 
The  locating face for the CSC should be clean and free from damage. 
When located correctly, fit the fixing bolts by tightening down evenly to 11nm/8lb ft. 
(or to the torque stated by the vehicle manufacturer). 
When connecting the hydraulic pipe, tighten the tube nut to 10-15Nm, or if ‘push type’ connectors are fitted, check that the ‘O’ Ring seals are in good condition before pushing together. 
Bleed the system as per the Vehicle Manufacturer’s recommendations. 
Finally check to establish that the pedal operation is satisfactory

Mechanical Release Bearing:

On fitting the release bearing it should be arranged so that the bearing is not in contact with the diaphragm spring fingers when the clutch is fully engaged

It is also IMPORTANT that the travel of the bearing, when operated, is to a controlled distance otherwise damage to the diaphragm spring can occur.
This travel can be limited by means of an external stop.


Historic Coil spring conversions:

Coil spring clutches were commonly fitted to Aston Martins, Bentleys in the UK along with American V8 Fords and Chevys. 

These clutches were very inefficient and as result are no longer manufactured. Helix Autosport can supply a modern replacement, however, this may require you to re-drill and tap your flywheel to fit it. 

Need to re-drill and dowel your flywheel to take a new cover?
Helix Autosport can do it for you, or email us for a drawing with machining details.