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Clutch Throwout Stop Adjustment Issues


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#1 unburntfuelinthemorning

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Posted 07 February 2020 - 10:27 AM

On the Minis I had in the 1990s I used to adjust the throwout stop as per the manual i.e. fully press down the clutch pedal, screw the nut in until it contacts the case, release the pedal, screw in a further one flat and fix in place with the locknut.  Never had any problems.

 

I've been doing this of late while trying to fix problems with clutch drag and I've bent the ball end of a few clutch arms which is starting to get old now.  It seems that when I've had problems selecting gears I've pressed the clutch really hard in a panic, the nut's hit the stop and the arms moved just a little more and bent the ball end. 

 

Now I don't know if it's just the effect of the heavy squats I've been doing but you'd think that if the stop's set as per the manual this surely shouldn't happen - but, if the stop is set as above then the nut will hit the case just before the pedal reaches full travel so I'm wondering if I would be best following the above setting procedure but not moving the nut in that extra flat before locking it off.



#2 nicklouse

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Posted 07 February 2020 - 10:36 AM

The reason you set it as described is so you do not overload the thrust washers and then fuse them to spin. Meaning engine out and lots of money.

 

if you have set it all as described then you have issues elsewhere.



#3 timmy850

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Posted 07 February 2020 - 10:52 AM

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch



#4 nicklouse

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Posted 07 February 2020 - 11:02 AM

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

the last line of that blog is the important one. i will not comment on the thoughts on setting the stop nuts. other than that.

Adjustment is important, but also unlikely to stop the crunching when you change gears - that is usually caused by wear in the in the hydrualic or mechanical linkages. There are lots of wearing parts, and all of them need to be checked and replaced if necessary

 



#5 unburntfuelinthemorning

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Posted 07 February 2020 - 11:20 AM

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

Interesting that - Calver also says to wind it out one flat and I thought it was a mistake.

 

 

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

the last line of that blog is the important one. i will not comment on the thoughts on setting the stop nuts. other than that.

Adjustment is important, but also unlikely to stop the crunching when you change gears - that is usually caused by wear in the in the hydrualic or mechanical linkages. There are lots of wearing parts, and all of them need to be checked and replaced if necessary

 

 

Totally agree about wear or other issues causing clutch drag, I was just wondering why the throwout stop is adjusted so it hits the stop before the pedal runs out of travel because then if you press hard enough you can move the clutch arm further and bend the ball end.
 



#6 nicklouse

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Posted 07 February 2020 - 11:42 AM

 

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

Interesting that - Calver also says to wind it out one flat and I thought it was a mistake.

 

 

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

the last line of that blog is the important one. i will not comment on the thoughts on setting the stop nuts. other than that.

Adjustment is important, but also unlikely to stop the crunching when you change gears - that is usually caused by wear in the in the hydrualic or mechanical linkages. There are lots of wearing parts, and all of them need to be checked and replaced if necessary

 

 

Totally agree about wear or other issues causing clutch drag, I was just wondering why the throwout stop is adjusted so it hits the stop before the pedal runs out of travel because then if you press hard enough you can move the clutch arm further and bend the ball end.
 

 

but you dont need to press more. when pressed as far as you can you will have released the clutch plate and also pushed the crank against the thrusts fully. the wind in a flat means that you do not put any extra load on the thrusts.

 

the original engines did not have stop nuts. they had thrust issues. stop nuts were added. thrust issues went.



#7 Rorf

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Posted 07 February 2020 - 11:48 AM

Other clutch issues being: ----- Pressure plate and ears skimmed incorrectly, flywheel skimmed incorrectly, clutch straps set up incorrectly, clutch diaphragm too strong. Then linkage problems being:--  wear in pivot points and clutch arm ball worn or bent, seen most commonly when the arm is heated up and bent to cater for all the wear or putting an extension on the slave cylinder arm.

 

There could be many different reasons for poor clutch response. Can even add in primary gear clearances poor and crankshaft thrust bearings worn out.



#8 nicklouse

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Posted 07 February 2020 - 12:03 PM

Other clutch issues being: ----- Pressure plate and ears skimmed incorrectly, flywheel skimmed incorrectly, clutch straps set up incorrectly, clutch diaphragm too strong. Then linkage problems being:--  wear in pivot points and clutch arm ball worn or bent, seen most commonly when the arm is heated up and bent to cater for all the wear or putting an extension on the slave cylinder arm.

 

There could be many different reasons for poor clutch response. Can even add in primary gear clearances poor and crankshaft thrust bearings worn out.

the set up i am removing is a grey with a bent arm on a lightened flywheel and has behave faultlessly since 94. stops wound in one flat. replacing with one of these new heavy duty jobs as they were not available back then.



#9 Moke Spider

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Posted 07 February 2020 - 06:15 PM

I hear your frustration there Unburnt, and really, if everything on the car is adjusted correctly, things like this, one should not be able to do from operation the driver controls. I've not done it myself (yet), but found loads of Arms like that.

 

It also highlights why doing things like fitting washers behind the bearing are not a good idea as it exacerbates the potential for issues like this.

 

I prefer to wind the stop nut out one turn

https://www.moke.com...ting-the-clutch

 

That's very poor advice, and if an issue develops with the clutch hose, it will lead to damage of the Crank Thrusts and possibly a Broken Centre Cap.

 

The correct way is to manually pull the Lever, I slip a length of pipe over the arm for this, and pull the Arm out until it stops. Wind the Flanged Nut down to the cover, then release the Arm. Then Wind on a further 0.007 to 0.010", which is near enough to one flat of the nut (0.009").



#10 unburntfuelinthemorning

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Posted 07 February 2020 - 08:02 PM


That's very poor advice, and if an issue develops with the clutch hose, it will lead to damage of the Crank Thrusts and possibly a Broken Centre Cap.

 

The correct way is to manually pull the Lever, I slip a length of pipe over the arm for this, and pull the Arm out until it stops. Wind the Flanged Nut down to the cover, then release the Arm. Then Wind on a further 0.007 to 0.010", which is near enough to one flat of the nut (0.009").

What sort of hose issue would cause problems?

 

Manually pulling the lever seems like a good idea as it removes any error from the external clutch operating system if it isn't up to scratch, I just haven't heard of doing it this way any where else.

 

So when you manually pull the lever until the arm stops then the crank is fully against the thrust washers, is that correct?  And the stops are adjusted so that the crank can't have any more pressure applied in that direction to avoid excessive wear on the thrust washers.



#11 Moke Spider

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Posted 08 February 2020 - 08:46 AM

The issue that occurs with the Clutch Hose is when they eventually deteriorate, they collapse internally and then act as a one way valve. When that happens, f you pump the clutch without these Over-thrown Nuts in place, you'll end up shoving the Crankshaft in to the Radiator. Doesn't make for a good day. The very first Minis didn't have these nuts and it was only as a result of a few warranty claims that there were fitted.

 

This is the factory advise on adjusting the nuts

 

VcDCShz.jpg

 

While it's not clear, it does appear that they are suggesting to do this adjustment by operating the hydraulics. I prefer to allow them to have a bit more movement than that, but stop them short of putting added pressure on the thrusts. This way, we can get more movement before bending the very end of the Arm where the Ball is and possibly breaking it off.

 

I don't think I have a file photo, but if you look on the flywheel side of the Diaphragm, there's 3 'stops' around the edge of that. When pulling the lever out manually until it stops, it;s these 'stops' coming in to contact with the flywheel that limits the movement here.

 

And in answer to your question, yes, the Over-throw Stop as adjusted short of binding on the Crank Thrusts.






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