clutch, spring versus diaphragm

[arthur r]

Has anyone got advice on converting a TR3A spring clutch to TR4 diaphragm. I know the flywheel and extension will need machining. Is it worth it in terms of a lighter and more reliable clutch operation?

[RogerH]

Hi Arthur,

it would be a 4A diaphragm clutch.

The mounting holes are different on the flywheel.

I think you can either machine new holes in the old wheel or fit a new wheel but the starter ring has to be considered.

 

The clutch on my 4A is very very light - I don;t know why as before I changed it last week it was quite stiff (compared to a modern car).

 

Roger

[BrianC]

Unless you have a problem with your left leg, stick with the spring clutch. There really isn't that much difference and the earlier design lasts longer and is just as reliable (if not more so) than the diaphragm clutch.

[Drewmotty]

The older design normally only needs a friction plate at replacement time whereas the later unit usually requires the lot binning.

Unles you're producing big horsepower from a highly modified engine I'd stick with the original.

[Lebro]

I changed mine to a diaphragm type, I used a "GT6" one from the TR shop.

I did this because I was fitting a saloon gearbox, & the input shaft splines are different.

This was in 2013, & the clutch has behaved perfectly so far, & is quite light in operation.

I did have to drill & tap new mounting holes, & dowel holes in the flywheel.

 

Bob.

[Dave Larnder]

Arthur

When I was about to start my reconstruction back in 2006 I asked John Sykes of TR Bitz for his thoughts and he said springs everytime.

BTW I had my flywheel lightened and the whole engine balanced with the clutch as well, and you can physically see the machining on the clutch assembly so it was the right thing to do to have it balanced too.

 

Dave