17 replies to this topic

[Spitz]

For the longest time I have had trouble with the clutch.

It's like I cannot get enough adjustm,ent. Constantly tough to get into gear 

 

So far I have changed master, slave, extended the rod going from arm to slave, adjusted the stop out as far as I dare.

 

I've got the wok off at the moment to see if there is anything obvious.  I will try to post pictures shortly.

 

I think I've done everthing I can to try to shift nor ally without a "crunch".

 

It's a pre-verto on a small bore, rod shift.

 

Engine is still in car, but I've got the cover and pressure plate off.  Not sure my puller will fit in there if I need to pull the flywheel

 

Thanks

[Spitz]

Pictures

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[rww]

Remove all carpets from under the clutch pedal and ensure that it goes fully to the floor or just short of if the throw out stops engage with the wok. Bleed the the slave, nipping up the bleed nipple with the pedal depressed. 

 

On the basis that you have changed the clutch master and slave cylinders then it should be safe to assume that they are giving the correct travel at the slave. I stand to be corrected but check that the linear travel at the slave rod is 0.5"

 

 When you check this travel, do it with the slave cylinder boot off so that you can see the slave piston pushing the rod. It is essential the slave piston does not hit against the circlip otherwise travel will be limited.If it is anywhere near the circlip on clutch pedal fully down then you do need to extend the pushrod. I did this only recently when I fitted a new (race) clutch plate which was slightly thicker than the previous design. Whatever you extend the rod with you must ensure that it will go through the circlip on the slave cylinder without any interfearance, otherwise travel is limited. From memory my extension to the pushrod is approx +5mm.

 

Minimise the clutch clearance adjustment to 10thou and the throw out stop to butting up to the wok at full pedal depression then one flat further in.

 

Best of luck. You are right, it can do your head in !

Edited by rww, 20 August 2019 - 05:49 PM.

[rww]

   The other thing  I have done is ensure that the diaphragm spring is flat when the clutch is relaxed/clamping. I had to take 20thou off the horns of the back plate to achieve this. Having the diaphragm flat before disengagement ensures that when pushed to release the diaphragm spring goes over centre, you can feel it in the pedal when it does.

 

This video explains how to do the above :

 

 

I believe the theory (?) behind this is in a Lindsay Porter Mini book.

Edited by rww, 20 August 2019 - 05:59 PM.

[imack]

That release bearing thrust plate looks worn out for starters. Is the ball on the end of the release arm worn out? Clevis pin in wok or clevis hole in wok worn? Clevis pin in clutch master cylinder worn? Clevis pin hole in pedal worn? A little bit of wear at any of these points can make the clutch difficult to disengage.

[Echan42]

I had this exact issue and it was due to wear in the mechanical parts, the arm, the plunger and the clutch bearing where on their way out.

I now get butter smooth shifting after changing all three.

 

Here are the part numbers for a pre verto

 

22A180MS 6,6000 1 In Stock  1G5999 1,5000 1 In Stock  22A2204MS 20,0000 1 In Stock  2A3601MS

Edited by Echan42, 21 August 2019 - 02:02 PM.

[Spitz]

I replaced all those bits a couple of yrs ago to try and solve the issue. My clut h rod is extended by a good inch also. (Welded)
I just realised i have to remove the flywheel anyway as i removed the pressure plate

[Cooperman]

Here is my detailed clutch drag fault finder:

 

CLUTCH DRAG

 

Clutch drag or failure to disengage is not an uncommon problem with the Mini.

There are several possible causes as follows:

1. HYDRAULIC SYSTEM

1. Wear in the pedal spindle or failure of the pedal to master cylinder clevis pin.
2. Failure of seals in the clutch master cylinder.
3. ‘Ballooning’ of flexible hose due to internal hose degradation or damage
4. Air in system due to inadequate bleeding
5. Failure of slave cylinder seals

 

1. MECHANICAL SYSTEM – WITHDRAWAL MECHANISM

1. Wear in top clevis pin
2. Wear in lower clevis pin
3. Bent arm
4. Worn or broken ball at lower end of arm where it engages into plunger.
5. Wear in plunger ball seat.
6. Incorrect setting of overthrow stop nuts
7. Incorrect setting of adjusting screw (pre-Verto)
8. Corrosion between plunger and clutch cover due to lack of lubrication.
9. Thrust bearing failure – accompanied by a lot of noise.

 

1. THE CLUTCH ASSEMBLY

1. Failure of clutch diaphragm spring due to fatigue or distortion
2. Centre plate hub not sliding on primary gear splines.
3. Clutch plate surface de-laminating or breaking up
4. Distorted clutch plate.
5. If fitted, clutch plate shock springs broken and causing a ‘jam’.
6. Primary gear not rotating freely on crankshaft due to either:                                                                                                                       i)   Insufficient primary gear end float,  ii)  Primary gear bushes seizing on crankshaft, or        iii) Primary gear bushes breaking up

[Spitz]

Thank you for that.

 

In watching this video https://youtu.be/pC91HqVCjFc

 I would lean towards your #6 above......as his description is exactly what is happening when I try to get into gear.

I took the engine out and took the clutch cover etc. off.

I don't feel any free play....well....perhaps 1 thou  (??).  I'm trying to move it back and forth here https://youtu.be/bXuTk9MftsE

 

it's an A series on an 1832 box if that info is needed.

 

Does it sound like that's my problem?  If so, how do I go about fixing this?

 

Thanks

[Spitz]

Do I need to split the block from the gearbox?

[Spitz]

Need to get this done before it gets too cold here.

 

Thanks for any direction

[Spitz]

I'm in a barren land here.  No other MINI owners for hundreds of km.  I rely on this and other sites for info......... 

[Spitz]

I have had a chance to get at my engine/box.

I have a very tight .003" of movement at the primary gear.  Is this enough?

 

Someone elsewhere mentioned that a shift lever in the box could be worn or loose on the pivot.....possible cause of tough gear engagement?

[timmy850]

I recently did my clutch and it's now excellent. One thing I did was to add in a washer between the plunger and bearing. This gives you a leverage advantage on the short side of the pivot, which makes a huge difference. You just need to make sure there is sufficient clearance to the diaphragm.


You can see the angle of the clutch arm here. The further from the slave cylinder the arm is, the further the slave needs to push to disengage the clutch

[Spitz]

You may have just touched on my problem here !

I actually made my push rod at the cylinder LONGER thinking this would help things.

 

In spring I will replace the plunger and look into the washer idea.

Too cold to work on things now unfortunately........April/May can't come soon enough!

 

Thank you @timmy850