19 replies to this topic

[Exmouth35]

Clutch has started slipping on my June 1960 Austin.
Looking at mini spares and other suppliers website they don't seem to list replacement parts for pre 1964.
I'd appreciate any info and recommendations for I'm assuming complete clutch assembly. I think the rear oil seal needs replacing as well.. a little oil drips from the jiggle pin.
Thanks in advance.

[nicklouse]

the plate is the same as the preverto as is the oil seal.

[Spider]

Oh,,,

 

The original Clutch arrangement in your Mini was a 'wet' (pressure Oil fed) Primary Gear and a Coil Spring Clutch. The Tail of your Crank, if original is 1-3/8"

 

The 'wet' primary gears were changed out in production around 1962 for a 'dry' type that was designed for dry running. They did this because of on going warranty claims from Oil leaking past the seals of the Primary Gear on to the Clutch. There was a conversion offered to convert 'wet' to 'dry' types. Hopefully, yours has been converted. The parts needed for the Wet primary gear are well and truly NLA, including the seals, however, your friendly Bearing Shop might be able to find suitable seals.

 

The Clutch Plate in yours is common to the rest of the Mini Range up to 83-ish when they went over to Verto Clutches, and so this isn't an issue.

 

The Coil Springs (which look similar to Valve Springs) are NLA. You can have your Springs Tested for 'poundage' and if OK, just refit them. If they are at all weak, you might be able to find some valve springs from another car that fit the bill.

 

There is I * think * a modification that can be done to the Flywheel so that it will accept a modern Diaphragm type Spring, I'll see if I can find some details. While it maybe tempting to just get a later Flywheel, there won't readily fit as from around 1963-64, the Tails of the Cranks went from 1-3/8" to 1-1/2", and so these won't fit. You maybe be able to swap out the Hub though to fit a later Flywheel, but you'd need to check that the flywheel when fitted up, sits in exactly the same place (depth) as the original.

 

If you trawl through some of the ebay US listings, sometimes parts for these come up.

[Exmouth35]

Thank you that's useful info.. will strip it out tomorrow and see what I have

Edited by Exmouth35, 19 January 2020 - 11:17 PM.

[surfblue]

Oh,,,

 

The original Clutch arrangement in your Mini was a 'wet' (pressure Oil fed) Primary Gear and a Coil Spring Clutch. The Tail of your Crank, if original is 1-3/8"

 

The 'wet' primary gears were changed out in production around 1962 for a 'dry' type that was designed for dry running. They did this because of on going warranty claims from Oil leaking past the seals of the Primary Gear on to the Clutch. There was a conversion offered to convert 'wet' to 'dry' types. Hopefully, yours has been converted. The parts needed for the Wet primary gear are well and truly NLA, including the seals, however, your friendly Bearing Shop might be able to find suitable seals.

 

The Clutch Plate in yours is common to the rest of the Mini Range up to 83-ish when they went over to Verto Clutches, and so this isn't an issue.

 

The Coil Springs (which look similar to Valve Springs) are NLA. You can have your Springs Tested for 'poundage' and if OK, just refit them. If they are at all weak, you might be able to find some valve springs from another car that fit the bill.

 

There is I * think * a modification that can be done to the Flywheel so that it will accept a modern Diaphragm type Spring, I'll see if I can find some details. While it maybe tempting to just get a later Flywheel, there won't readily fit as from around 1963-64, the Tails of the Cranks went from 1-3/8" to 1-1/2", and so these won't fit. You maybe be able to swap out the Hub though to fit a later Flywheel, but you'd need to check that the flywheel when fitted up, sits in exactly the same place (depth) as the original.

 

If you trawl through some of the ebay US listings, sometimes parts for these come up.

See this link from the Mk1 forum

 

http://mk1-forum.net...l spring clutch

 

(I'm miniminor on there).

 

My 63' Mk1 is still running on a narrow tail crankshaft and coil spring clutch, replaced clutch plate itself several years ago.

There is a link in the above thread

 

http://mk1-performan..._mechanical.htm

 

which shows how a coil sprung flywheel can be modified to take a diaphram clutch spring if you wish to have a little machining done.

 

I seem to remember reading somewhere that 997 Cooper valve springs are the same as used in the coil spring clutch set up?

[Spider]

 

Oh,,,

 

The original Clutch arrangement in your Mini was a 'wet' (pressure Oil fed) Primary Gear and a Coil Spring Clutch. The Tail of your Crank, if original is 1-3/8"

 

The 'wet' primary gears were changed out in production around 1962 for a 'dry' type that was designed for dry running. They did this because of on going warranty claims from Oil leaking past the seals of the Primary Gear on to the Clutch. There was a conversion offered to convert 'wet' to 'dry' types. Hopefully, yours has been converted. The parts needed for the Wet primary gear are well and truly NLA, including the seals, however, your friendly Bearing Shop might be able to find suitable seals.

 

The Clutch Plate in yours is common to the rest of the Mini Range up to 83-ish when they went over to Verto Clutches, and so this isn't an issue.

 

The Coil Springs (which look similar to Valve Springs) are NLA. You can have your Springs Tested for 'poundage' and if OK, just refit them. If they are at all weak, you might be able to find some valve springs from another car that fit the bill.

 

There is I * think * a modification that can be done to the Flywheel so that it will accept a modern Diaphragm type Spring, I'll see if I can find some details. While it maybe tempting to just get a later Flywheel, there won't readily fit as from around 1963-64, the Tails of the Cranks went from 1-3/8" to 1-1/2", and so these won't fit. You maybe be able to swap out the Hub though to fit a later Flywheel, but you'd need to check that the flywheel when fitted up, sits in exactly the same place (depth) as the original.

 

If you trawl through some of the ebay US listings, sometimes parts for these come up.

See this link from the Mk1 forum

 

http://mk1-forum.net...l spring clutch

 

(I'm miniminor on there).

 

My 63' Mk1 is still running on a narrow tail crankshaft and coil spring clutch, replaced clutch plate itself several years ago.

There is a link in the above thread

 

http://mk1-performan..._mechanical.htm

 

which shows how a coil sprung flywheel can be modified to take a diaphram clutch spring if you wish to have a little machining done.

 

I seem to remember reading somewhere that 997 Cooper valve springs are the same as used in the coil spring clutch set up?

 

 

I did actually see your post over there

 

The Springs were colour coded for their 'poundage'. The 850 had 'red' springs and the 997 Cooper had Black with a White Dot coloured Springs.

 

Clever finding the wheel bearing seal at the same size, though I'm not sure it would really have the temperature capability ??  Then again, I think you said yours has been going a while now.

 

Cheers for the link on the flywheel mods

[Exmouth35]

Really interesting reading.
I've removed the casing cover and the housing edge was very oily so clearly the seal has failed.
I'm waiting for minispares delivery including the flywheel puller.
Just reading bmc workshop manual it looks like they suggest an industrial press to dismantle and re assemble the clutch onto flywheel. Again any tips welcome.
I'm also looking forward to changing the oil seal!!

[AP2020]

Really interesting reading.
I've removed the casing cover and the housing edge was very oily so clearly the seal has failed.
I'm waiting for minispares delivery including the flywheel puller.
Just reading bmc workshop manual it looks like they suggest an industrial press to dismantle and re assemble the clutch onto flywheel. Again any tips welcome.
I'm also looking forward to changing the oil seal!!

 

If your flywheel won't come off google guessworks mini gearboxes as he has a HD puller

[AP2020]

...

 

The Clutch Plate in yours is common to the rest of the Mini Range up to 83-ish when they went over to Verto Clutches, and so this isn't an issue.

 

....

 

Pretty sure the Verto was first used august 1984

[Spider]

Really interesting reading.
I've removed the casing cover and the housing edge was very oily so clearly the seal has failed.
I'm waiting for minispares delivery including the flywheel puller.
Just reading bmc workshop manual it looks like they suggest an industrial press to dismantle and re assemble the clutch onto flywheel. Again any tips welcome.
I'm also looking forward to changing the oil seal!!

 

The few I've done, I just pulled up on the backing plate bolts.

 

These really do need to be assembled on the bench and then fitted as an assembly. The Workshop Manual also refers to a tool for centring the clutch plate with prior doing up the backing plate bolts (as after, it will be all clamped together). You can in fact use the Primary Gear for doing this with.

 

You'll need to check the clearances in the Primary Gear Bearings too as when they have excessive clearances, this too will make them leak.I'm just trying to find the wear limit on these. New Bearings have a clearance of 0.0025 to 0.003" . These are a White Metal Bearing, similar to the Camshaft Bearings.

[surfblue]

Clever finding the wheel bearing seal at the same size, though I'm not sure it would really have the temperature capability ??  Then again, I think you said yours has been going a while now.

 

Not mine - must be someone elses on that thread, I deffo used a proper crankshaft seal.

 

 

Just reading bmc workshop manual it looks like they suggest an industrial press to dismantle and re assemble the clutch onto flywheel. Again any tips welcome

 

 

You dont need a press to assemble the clutch just about 4 hands!

An assistant to compress the springs while the bolts are popped in and nipped up is beneficial. Or a couple of G cramps. (Why are they called G cramps and not G clamps? Never understood that!

[Exmouth35]

Well my Minispares flywheel puller arrived today. I had to shorten the centre bolt a bit so I could get a big socket and wrench attached..
It's now seriously tight.. I put a fan heater on it for half hour to get it hot.. still not moving.
Kettle of boiling water poured over and pop!

Edited by Exmouth35, 23 January 2020 - 07:49 PM.

[surfblue]

Well what have you got in there, is it still the old coil sprung, narrow tail crank set up?

[Exmouth35]

[quote name="surfblue" post="3631028" timestamp="1579893476"]Well what have you got in there, is it still the old coil sprung, narrow tail crank set up?[/quote
Yes its all original..coil spring clutch, narrow crank. All seems to be in good condition probably preserved by the oil.
The red seal was definitely the culprit.
I've de greased everything and will try to find time to change the seal and reassemble with the new clutch plate next week.

[Exmouth35]

I did try to upload some photos but it said file too large.