Article on The Internet Mini Encyclopædia
What is the difference between Verto and non verto clutches?
"I have just been through the what clutch saga for my new 1310. In the process I found out pretty much everything about mini clutches.
This clutch was used from early 60's to 1982. It has the pressure plate on the engine side of the flywheel, and the diaphragm sits on the outside pulling the pressure plate into the flywheel, through holes in the flywheel, sandwiching the friction plate. This type of clutch is just as good as the verto, but is prefered by the big-engined mob since more upgraded parts are available/cheaper. Lightened flywheels and fast friction plates are common/cheap. The bad things about the old-style is that it does tend to snatch on (even in standard form).
This newer clutch was fitted from 1983 onwards. The metro had started off in 1980 with a non Verto clutch then went to Verto later on in 1983, then in 86 went to cable operated Verto. It was designed to be lighter operating and have a smoother pickup (springs in middle of friction plate). The diaphragm and pressure plate is all in one and sits on the outer side. This moves towards the engine to squash the friction plate against the flywheel. The diaphragm assembly is more expensive that the old-style but seldom needs renewing, as it's very meaty. The old-style friction plate is directly swappable with a verto plate, so you can use uprated old-style plates in a verto. The flywheel has a large centre hole, and it's the diaphragm that sits on the crank, hence it's easier to remove the assembly (still need puller). Also, the verto clutch requires a greater throw, hence the use of a shorter clutch arm. If you use the long arm on a verto it won't disengage fully and you won't be able to get in some gears!
For my 1310 (GT block/crank) I used a 90k mile verto assembly from a scrap 998cc A+ and stuck a AP Racing Old-style friction plate in it. This is what the MG Metro Turbo does. It works fine."
How do they work?
It's difficult to see at first but obvious once you know!
The secret lies in the spring 'fingers' that point inwards on the diaphragm. These are actually levers. When the release bearing pushes on the thrust cup this pushes each finger down. The other ends on the fingers are attached to the 'main spring' steel band which flexes upwards, allowing the (built in) pressure plate to lift off the friction plate. Push on a spring finger and you'll see.
The release bearing pushes the diaphragm and this pushes the pressure plate away from the flywheel through the three holes in the flywheel. This disengages the friction plate. The 'main spring' is the steel band inside the diaphragm!
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