Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Clutch

I've put together some notes regarding the clutch. Some of the info is available elsewhere, but I thought it worth dumping it here also.

Friction & Pressure plates
The clutch plate components are manufactured by TTV Racing in Bury St. Edmonds. As far as we know, the clutch is a custom design for the M3W. TTVR will not deal direct with customers regarding M3W products.
CG Motorsport can refurbish used components to ‘as new’ at reasonable prices. (86 Jack Lane, Hunslet Leeds, West Yorkshire, LS10 1BN Tel: 01132 426 359)
Note: There has been some anecdotal talk that early cars were fitted with a smaller clutch plate.

Clutch Master Cylinder
This seems to be made especially for this application and is supplied to Morgan by Liberty Vehicle Technologies (LVT) 920E. Morgan Part Number: U120071. It has a 15.8mm (5/8") bore.

Note: It appears to be similar to Ferodo FHC5109 (Saab 9000 items 4385019/8957292). I’m not saying that it’s the same, just that it may warrant further investigation in the future if supplies of the U120071 dry up. The obvious differences are the bent fluid inlet pipe and the non-adjustable actuating rod.

However, as the Saab item is more expensive than the M3W one, you might as well buy it from a Morgan dealer while you can.

I found it impossible to replace the clutch master cylinder without removing the entire pedal box from the car. This involves disconnecting the throttle cable from the pedal assembly and also disconnecting the three hydraulic hoses from the bulkhead fittings high up in the footwell. The hydraulic fluid reservoir is unbolted from the bulkhead and passed through the access panel so that it can be removed from the car still attached to the pedal box.

Warning: If you want to avoid copious amounts of hydraulic fluid spreading everywhere, my advice is to drain the entire brake & clutch system before disconnecting the hydraulic hoses. This is made easy by using a vacuum extractor such as Sealey TP69 which is also very useful when doing engine oil changes.

Slave Cylinder/Thrust Bearing
The majority of cars, certainly up until some time in 2018/19, M3W’s are fitted with a concentric slave cylinder/thrust bearing. This is an add-on to the Mazda gearbox that is supplied by Vitesse Ltd, Hinkley, UK.

Part Numbers (for the slave cylinder/thrust bearing only):
- Volvo 8675052 (Volvo C30, C70 (2006-), S40 V50 (2004-) + others)
- Landrover LR022452 (Freelander 2)
- Jaguar 456R7A564AA

These are readily available on eBay for less than 1/3 of the price of replacements from MMC or Volvo. They are known to fail without any external signs of failure (such as leaking hydraulic fluid for instance).
Note: Some cars are fitted with the Mazda external slave cylinder, although I've never come across one.

Once the engine is out (!) the slave cylinder is easy to change. It is held in position by a single small bolt that is loctited into position. There is a small locking clip that needs to be removed from the hydraulic connector with long-nosed pliers, following which the vertical connecting tube can be lifted up and the cylinder will be free to slide out.


Bleeding
The clutch bleed nipple is on top of the gearbox bell housing below the oil tank.

Space in this region is very limited so I found it useful to cut down an old 11mm spanner to around 65mm long so that I could get a reasonable swing on the bleed nipple.

The bleed nipple needs to be loosened more than expected to allow fluid to exit the fitting and I found that it was not easy to judge this point which made bleeding via the usual two man method tricky [i.e. open nipple, pedal down, close nipple, pedal up]. Therefore, I thoroughly recommend using a Gunson EeziBleed pressurized system, which makes the process much more straightforward.

Note: The feed to the clutch master cylinder exits the reservoir from the side at a higher level than the hoses leading to the brake master cylinder. Thus, in the event of a hydraulic leak in the clutch system, brake operation remains unaffected. This does mean however that the reservoir needs to be kept quite full while bleeding the clutch system.

Note: Early cars were fitted with three separate fluid reservoirs.

Testing
It may prove useful to test operation of the slave cylinder before bolting the engine and gearbox back together.
Warning: Do not be tempted to try the clutch pedal before the clutch pressure plate is re-fitted. If you do, the piston will be ejected from the slave cylinder housing with a corresponding loss of hydraulic fluid under pressure. If you are unfortunate to have this happen to you then hopefully the piston and cylinder can be reunited by carefully squeezing the assembly in a vice but it’s better to avoid the issue! [You can guess how I know this....]

Therefore, once the hydraulic pipe has been unclipped from the slave cylinder, the bleed manifold and pipe can be fed up through the hole in the bell housing and threaded to the front of the oil tank where it can be reconnected with the slave cylinder. Then, after fitting a clamp to prevent inadvertent disassembly of the slave cylinder, it can be bled and tested outside the vehicle.

In the side of the gearbox there is an oblong cutout, fitted with a rubber grommet. I believe this is for the MX-5 clutch release lever? In any case, it is just possible to observe the operation of the slave cylinder through this hole with the aid of a dentist’s mirror or endoscope.