10 replies to this topic

[mike.]

Hi guys,

Been having some problems with my pre-verto clutch. Main issue was that the car would be hard to get into 1st gear, it would always take a few attempts before it would engage and I found I was crunching gears ever so slightly whilst driving.

The system is well bled and the problem didn't improve with pumping the pedal, so I was convinced it is a problem with the pivot or adjustment.

I stripped the pivots off, the arm/clevis pins and the pushrods and found a small amount of wear on the clevis pins and the ball on the bottom of the arm. The arm was an old item but the clutch plunger was new. So I replaced all the bits so now it had all new clevis pins, pushrod, arm. The slave cylinder is also new as is the braided hose.

I then played around with the adjustments, both the return stop and throw out stop nuts but still couldn't get it quite right. I then discovered that the clutch end cover or 'wok' had cracked near the pivot:



So I sourced a new cover and have just fitted it.

I imagine the crack was caused by having the throwout stop nuts adjusted too tight, followed by compressing the clutch pedal hard down to the floor in an attempt to get the car in gear.

I have adjusted the throwout stops as per the haynes manual, i.e. until the nut butts up against the cover, then one further flat. I think maybe what happened was the nut was moved turned further by mistake whilst tightening the locknut.

This photo showed how my clutch is currently adjusted with the new cover



This is using the haynes manual method, and it leaves the throwout stop around 1.5mm from the wok. The clutch feels fine (i've not tried with the engine running yet) and it doesn't hit the floor.

Does this look about right? It just seems very close to me.

I found this guide:

http://www.7ent.com/...adjustment.html

Which says to just use a 1/8" drill bit to set the clearance. This would give me over double the clearance I have now but then may cause thrust washer issues...

I'm going to try driving the car with it as is and see how the gears engage. If i'm still having problems i'll try adjusting the clearance to around 3mm and see how it works for a short distance.

Just wondering somebody more experience can tell me roughly how close the throwout stop should sit to the clutch cover?

[Jordie]

you got the return spring on the top of the arm?

looks close on the throwout nuts to me. doesnt look like it will fully disengage.

[sonikk4]

Even the BMC manual says 1.52 mm or .50 mm.

[Cooperman]

When adjusting a pre-Verto clutch you should first of all back the overthrow nuts well away from the casing. Then check that the top of the clutch arm moves at least 0.55" linearly. If it moves less then there is a problem with either the clutch pedal arm to slave cylinder rod clevis pin or a hydraulic system.
Assuming the arm moves 0.55" or more at its very time.
Then pull the arm as far as it will go towards the inner wing, i.e. away from the engine, and set the stop gap to 0.020" and lock it with the 7/16" AF nut.
Finally have someone push the clutch pedal right to the floor and screw in the inner overthrow nut in until it just touches the clutch cover. Release the pedal and turn the nut a further 1/2 a flat inwards. Without the inner nut moving, lock it with the outer nut.
The clutch is now set correctly.

[sonikk4]

Mike did i send you a copy of the BMC workshop manual??

[mike.]

The return spring is not fitted at the moment and was not fitted during adjustment, but will be fitted when test driving.

Cooperman - That is how I have adjusted it, however i've not measured the linear movement of the arm/pushrod. It moves quite a lot, but I will measure it to be sure. Also, the throwout stop is adjusted until it touches the cover, then 1 full flat further. I'll readjust it to half a flat.

The clutch feels fine without engine running and doesn't stop early nor hit the floor, it just looks like a small amount of throwout clearance, and then after reading that guide which said 1/8" it confused me further.

Sonikk - Nope i've not seen the BMC manual, would love a copy if you have it as it seems to be full of the detailed little clearances that the haynes doesn't have.

Edited by mike., 11 March 2013 - 08:43 PM.

[sonikk4]

The return spring is not fitted at the moment and was not fitted during adjustment, but will be fitted when test driving.

Cooperman - That is how I have adjusted it, however i've not measured the linear movement of the arm/pushrod. It moves quite a lot, but I will measure it to be sure. Also, the throwout stop is adjusted until it touches the cover, then 1 full flat further. I'll readjust it to half a flat.

The clutch feels fine without engine running and doesn't stop early nor hit the floor, it just looks like a small amount of throwout clearance, and then after reading that guide which said 1/8" it confused me further.

Sonikk - Nope i've not seen the BMC manual, would love a copy if you have it as it seems to be full of the detailed little clearances that the haynes doesn't have.

Pm me your email address and i will send it on to you.

[Cooperman]

I had exactly that with a car where the engine was working fine, but it was taken out to do some other work. Then after re-installing the clutch would not dis-engage enough to get it into gear cleanly. It all looked fine with the arm moving and everything set as above. Luckily I had my own 1964 car alongside, so I measured the travel at the tops of the arms. My car was 0.58" and the other was 0.35".I changed the clurtch slave cylinder, bled it out and the arm top moved 0.55". Re-set all the other settings and it was perfect.
It doesn't take much to screw up a Mini clutch operation.

[mike.]

Ok i've been and checked the clutch again. I've checked the the linear movement of the slave pushrod and it is exactly 0.55" so no problems there.

I've got the return stop set at 0.020" and I set the throwout stop half a flat past initial contact with the cover. This leaves the throwout stop 2mm from the cover. It doesn't look like much and that other guide says it should be 1/8" gap. But i've got full movement at the pedal end without it hitting the floor so only a test drive tomorrow will show if i've solved the gear selection issues.

[Woreign]

Should there be any play between the hole in the plunger and the ball at the end of the lever? Mine has a small amount, which I'm sure makes a big difference in operation. Everything is new on the clutch system, except the plunger. The pedal still goes to the floor, so I'm thinking this might be my problem...

Edit: I had adjusted my clutch for the Verto style, not the pre-verto. After adjusting correctly, things ar emuch better.

Edited by Woreign, 22 March 2013 - 02:04 PM.

[IainNeon91]

Ok i've been and checked the clutch again. I've checked the the linear movement of the slave pushrod and it is exactly 0.55" so no problems there.

I've got the return stop set at 0.020" and I set the throwout stop half a flat past initial contact with the cover. This leaves the throwout stop 2mm from the cover. It doesn't look like much and that other guide says it should be 1/8" gap. But i've got full movement at the pedal end without it hitting the floor so only a test drive tomorrow will show if i've solved the gear selection issues.

Hi there mate, I don't suppose you solved this did you?? I'm having the same issues as you, it takes a few attempts to get it into first, and sometimes crunches....

 

Cheers.