20 replies to this topic

[BrianHJ]

I have a 63 Mini Minor 850 with a spring loaded, not diaphragm clutch.  Can I replace it for a diaphragm, or do I need to keep it and just change the plate.  I also have a slight leak on the seal, do all versions of the seal fit.

[Spider]

You can change it to a Diaphragm Clutch, though yours will be a 'thin tail' crank, so there's a modification you need to do to the flywheel OR you can swap the hub from yours to a slightly later diaphragm flywheel.

 

The big Oils were all the same size, I've found the best are the Mini Spares ones. The Inner Seal is the same size as a front wheel bearing one. While you can use these, you'd be best off getting on in Silicon (like the big seal), to better deal with the heat.

[bob01b]

I also have a late 63 with original 850 and coil spring clutch.  When I researched this (just in case) I found crankshafts after engine 8AM-U-H551625 should be 1.5" dia. tail shaft.  That information came from "Anatomy of the classic mini" by Mark Huthert found on "google books" page 71

[BrianHJ]

I also have a late 63 with original 850 and coil spring clutch.  When I researched this (just in case) I found crankshafts after engine 8AM-U-H551625 should be 1.5" dia. tail shaft.  That information came from "Anatomy of the classic mini" by Mark Huthert found on "google books" page 71

I had read this as well, the crank seems to taper down a little and is smaller than 11/2", can you still leave in the spring one as it only looks like the plate is worn.

[BrianHJ]

You can change it to a Diaphragm Clutch, though yours will be a 'thin tail' crank, so there's a modification you need to do to the flywheel OR you can swap the hub from yours to a slightly later diaphragm flywheel.

 

The big Oils were all the same size, I've found the best are the Mini Spares ones. The Inner Seal is the same size as a front wheel bearing one. While you can use these, you'd be best off getting on in Silicon (like the big seal), to better deal with the heat.

I was told that these are hard to come by now, is it the thickness that the difference is or other things.  I may try and leave it original if not just needing machined, but will get a silicone seal on your advice.

[Spider]

There's not much that needs doing, but you'll need to find someone with a lathe to do it for you

 

 

If you look around, you might find a set of replacement springs. I wouldn't be running with the ones that are in there, they do fatigue & settle.

[GraemeC]

Swapping the hub sounds an easy fix - I’m sure I have a spare 2 piece diaphragm type flywheel.
(Assuming you’re in the U.K. - can’t see in mobile site)

[BrianHJ]

Swapping the hub sounds an easy fix - I’m sure I have a spare 2 piece diaphragm type flywheel.
(Assuming you’re in the U.K. - can’t see in mobile site)

Graeme I am in central Scotland

[GraemeC]

Let me see what I can find over the weekend.
I’m not quite as North as you, I’m in the southern end of the Lake District.

[BrianHJ]

Let me see what I can find over the weekend.
I’m not quite as North as you, I’m in the southern end of the Lake District.

Thanks anyway Graeme, when I phoned mini spares they said that I would also need to change the crank to an 1 1/2" one as the clutch wont work with the tapered crank fitted to this age of 850.  As the car is so old there are a lot of differing views on how to tackle this job, with some saying it can be done just by getting the flywheel shaped to fit the diaphragm without changing the crank to the wider one or worst still replacing an engine that is still only in the 28000 mile mark, and some saying no. 

 

I would love a full list of options and parts required as I cannot be the only one with this predicament.

 

Thanks Brian

[Spider]

, when I phoned mini spares they said that I would also need to change the crank to an 1 1/2" one as the clutch wont work with the tapered crank fitted to this age of 850.

 

The Clutch plates from 1959 up to 1984-ish while underwent some small changes, were all 100% interchangable. With either some small machining or a later flywheel to bolt to your hub, the diaphragm spring will also fit and work. I've done quite a few.

There's no need to change out your crank for reasons to do with a replacement clutch.
 

[BrianHJ]

 

, when I phoned mini spares they said that I would also need to change the crank to an 1 1/2" one as the clutch wont work with the tapered crank fitted to this age of 850.

 

The Clutch plates from 1959 up to 1984-ish while underwent some small changes, were all 100% interchangable. With either some small machining or a later flywheel to bolt to your hub, the diaphragm spring will also fit and work. I've done quite a few.

There's no need to change out your crank for reasons to do with a replacement clutch.

Thank you for the information, it helps a lot.

 

Cheers Brian

[Spider]

To perhaps give you a bit more confidence here, this is from an Australian Parts Book;-

 

 

2 things to note from that is i) it refers to a Coil Spring Clutch and ii) the Part Number for the plate is AYG3088.

 

and then here;-

 

 

Again, 2 things to note is that i) it refers to a Diaphragm Spring Clutch and ii) the Part Number for the Clutch Plate is AYG3088, same as that used in the Coil Spring Clutch.

[BrianHJ]

To perhaps give you a bit more confidence here, this is from an Australian Parts Book;-

 

 

2 things to note from that is i) it refers to a Coil Spring Clutch and ii) the Part Number for the plate is AYG3088.

 

and then here;-

 

 

Again, 2 things to note is that i) it refers to a Diaphragm Spring Clutch and ii) the Part Number for the Clutch Plate is AYG3088, same as that used in the Coil Spring Clutch.

Thanks again, knowledge is key to any job. I have ordered the oil seal and tool, now I need to get everything else organised to tackle this.

[BrianHJ]

I have now replaced the clutch, got the flywheel reshaped as suggested and changing to the diaphragm type; I replaced the levers and plunger for good measure.  I now cannot get any pressure on the plunger when adjusting until the pin in the cylinder is fully out and it will not go any further as it is fully to the end of travel. I think it could do with a spacer/washers to take up the play. I thought between the diaphragm and the back pressure plate to get it closer to the release bearing. Would this work, and can I get some suggestions please.  The clutch cylinder is now not returning with the spring, not having a good day.