84 replies to this topic

[postve]

Hey Graeme, I am thinking on completely draining the clutch system and starting from scratch, this has to be a hydraulics issue IMHO as everything else, clutch, puller, arm, master cylinder, slave plunger, nut, etc is brand
New???????? Truly wondering if at the end of the day I have a hydraulic issue?

Edited by postve, 20 November 2022 - 04:26 PM.

[GraemeC]

I'd tend to disagree - In my head if it works with the nuts backed off but not with them adjusted as per the manual, then it has to be either an out of tolerance part or something you're missing when assembling.

If it was the hydraulics the throw out nuts would make no difference.

 

(Controversially, I don't think the throw out nuts are that important as the setting procedure isn't great. On my own car, after them 'self adjusting' at the start of a rally this weekend I spent the rest of 2 rallies with them in my pocket)

[postve]

Lol - I have heard repeated calls to toss the nuts to be honest. As for hydraulic, pure speculation as I did a thorough test, clutch pressed agreeively, camera on to see if any leaks etc etc . Nothing so good as far as I am concerned. Going to re-examine the ball and change return spring when I get a chance today

[sonscar]

Are not the nuts there to limit thrust on the crank?Steve..

[Spider]

It will work without the Overthrow Nuts, but it's not wise to not fit them and have them correctly adjusted.

Minis when first produced didn't have these nuts (or the thread to fit them to), but in fairly short time, they were fitted due to warranty claims, from severely worn crank thrusts and even a few broken centre main caps.

[postve]

It will work without the Overthrow Nuts, but it's not wise to not fit them and have them correctly adjusted.

Minis when first produced didn't have these nuts (or the thread to fit them to), but in fairly short time, they were fitted due to warranty claims, from severely worn crank thrusts and even a few broken centre main caps.

Sound advise Spider and just doing so in the short run as they don't add these things unless a good reason as you explained. From what I read it's there to stop arm from extending too far and as mentioned, damage wok and worst case damage crankshaft.

[GraemeC]

Are not the nuts there to limit thrust on the crank?Steve..

 

So, you set them by pushing the clutch to the floor, screw them in until they hit the wok, release clutch and then turn them in one more flat, which on the fairly fine thread is minimal distance.

So if pushing the clutch in initially already loads the crank thrusts up excessively (or the diaphragm which is the other commonly cited reason for them), how does that slight final adjustment alleviate that?

 

And remembering what is actually happening when you push the clutch, you'd have to be able to push the thrust plate so far that there was absolutely no more travel of the diaphragm. or that the thrust plate had hit the flywheel bolt, before you'd load the crank thrusts up any more than they are in normal operation.

 

Don't get me wrong - I do usually have them fitted.  But more because they're there than a belief they're needed.  When removing mine at the weekend I did make that first press of the clutch very cautiously to ensure there was not drop in revs etc that would indicate the thrusts complaining.

 

I personally believe that the addition of them at the factory was when coil spring clutches were used which could become coil bound, but the later diaphragm clutches didn't really need them.

[sonscar]

See spiders post,they are there for a reason.I did not design the clutch mechanism and I doubt Leyland would have fitted them if it could get away with not doing so.Jst saying,that's all.Steve..

[Spider]

 

It will work without the Overthrow Nuts, but it's not wise to not fit them and have them correctly adjusted.

Minis when first produced didn't have these nuts (or the thread to fit them to), but in fairly short time, they were fitted due to warranty claims, from severely worn crank thrusts and even a few broken centre main caps.

Sound advise Spider and just doing so in the short run as they don't add these things unless a good reason as you explained. From what I read it's there to stop arm from extending too far and as mentioned, damage wok and worst case damage crankshaft.

 

Sure, diagnose the issue here without the nuts, but I'll suggest just be sure that the movement of the clutch system is 'bottoming out' by the pedal hitting the floor first than the Crankshaft burning out the Thrusts.

 

 

 

Are not the nuts there to limit thrust on the crank?Steve..

 

So, you set them by pushing the clutch to the floor, screw them in until they hit the wok, release clutch and then turn them in one more flat, which on the fairly fine thread is minimal distance.

So if pushing the clutch in initially already loads the crank thrusts up excessively (or the diaphragm which is the other commonly cited reason for them), how does that slight final adjustment alleviate that?

 

Actually, the way suggested in the workshop manual (and also how I've always set them) is to pull the Clutch Arm 'directly by hand' out all the way until it stops, though often a lever is needed, hold it there and wind the fanged nut on all the way to the Wok, then release the Arm and wind the Nut on a further 0.007 to 0.010", (though I just go another flat on the nut), hold it there and lock it off with the lock nut.

It's not to set a Stop, but a Limit should something cause the Clutch Hydraulics not to return all the way and start pumping themselves out with use, like for example an old hose that's collapsing on the inside.

 

In my own car, with the Over-thrown Nuts set correctly, the pedal actually stops about 20 mm from the floor (and also would stop about the same point without them set). Here, if I didn't have these Nuts set correctly, I'd be shoving the Crankshaft in to the Radiator.
 

[Lplus]

 

 

It will work without the Overthrow Nuts, but it's not wise to not fit them and have them correctly adjusted.

Minis when first produced didn't have these nuts (or the thread to fit them to), but in fairly short time, they were fitted due to warranty claims, from severely worn crank thrusts and even a few broken centre main caps.

Sound advise Spider and just doing so in the short run as they don't add these things unless a good reason as you explained. From what I read it's there to stop arm from extending too far and as mentioned, damage wok and worst case damage crankshaft.

 

Sure, diagnose the issue here without the nuts, but I'll suggest just be sure that the movement of the clutch system is 'bottoming out' by the pedal hitting the floor first than the Crankshaft burning out the Thrusts.

 

 

 

Are not the nuts there to limit thrust on the crank?Steve..

 

So, you set them by pushing the clutch to the floor, screw them in until they hit the wok, release clutch and then turn them in one more flat, which on the fairly fine thread is minimal distance.

So if pushing the clutch in initially already loads the crank thrusts up excessively (or the diaphragm which is the other commonly cited reason for them), how does that slight final adjustment alleviate that?

 

Actually, the way suggested in the workshop manual (and also how I've always set them) is to pull the Clutch Arm 'directly by hand' out all the way until it stops, though often a lever is needed, hold it there and wind the fanged nut on all the way to the Wok, then release the Arm and wind the Nut on a further 0.007 to 0.010", (though I just go another flat on the nut), hold it there and lock it off with the lock nut.

It's not to set a Stop, but a Limit should something cause the Clutch Hydraulics not to return all the way and start pumping themselves out with use, like for example an old hose that's collapsing on the inside.

 

In my own car, with the Over-thrown Nuts set correctly, the pedal actually stops about 20 mm from the floor (and also would stop about the same point without them set). Here, if I didn't have these Nuts set correctly, I'd be shoving the Crankshaft in to the Radiator.
 

 

This.  What stops the movement is the thrust bearing contacting the crankshaft/flywheel bolt.  I might leave a bit more than a flat clearance, but no more than 2 or 3 flats.

[Spider]

Hope this isn't going off topic but here's a little bit of a history lesson on Clutches and adjustment.

 

Factory Service Bulletin from April 1960 regarding Clutch Adjustment, note too in the drawing, there's no provison for the Over-throw Nuts at all, but it was clear, by this point, with the car only being on the market about 8 months they were getting warranty claims;-

 

 

 

Then finally in September the same year, we got the Over-throw Nuts;-

 

 

[Spider]

 

Actually, the way suggested in the workshop manual (and also how I've always set them) is to pull the Clutch Arm 'directly by hand' out all the way until it stops, though often a lever is needed, hold it there and wind the fanged nut on all the way to the Wok, then release the Arm and wind the Nut on a further 0.007 to 0.010", (though I just go another flat on the nut), hold it there and lock it off with the lock nut.

It's not to set a Stop, but a Limit should something cause the Clutch Hydraulics not to return all the way and start pumping themselves out with use, like for example an old hose that's collapsing on the inside.

 

In my own car, with the Over-thrown Nuts set correctly, the pedal actually stops about 20 mm from the floor (and also would stop about the same point without them set). Here, if I didn't have these Nuts set correctly, I'd be shoving the Crankshaft in to the Radiator.
 

 

 

This.  What stops the movement is the thrust bearing contacting the crankshaft/flywheel bolt.  I might leave a bit more than a flat clearance, but no more than 2 or 3 flats.

 

No sorry. You don't set the Flange Nut with clearance here, you wind it ON a further flat (or 2 or 3 I'd say should be OK).
 

[Lplus]

 

 

Actually, the way suggested in the workshop manual (and also how I've always set them) is to pull the Clutch Arm 'directly by hand' out all the way until it stops, though often a lever is needed, hold it there and wind the fanged nut on all the way to the Wok, then release the Arm and wind the Nut on a further 0.007 to 0.010", (though I just go another flat on the nut), hold it there and lock it off with the lock nut.

It's not to set a Stop, but a Limit should something cause the Clutch Hydraulics not to return all the way and start pumping themselves out with use, like for example an old hose that's collapsing on the inside.

 

In my own car, with the Over-thrown Nuts set correctly, the pedal actually stops about 20 mm from the floor (and also would stop about the same point without them set). Here, if I didn't have these Nuts set correctly, I'd be shoving the Crankshaft in to the Radiator.
 

 

 

This.  What stops the movement is the thrust bearing contacting the crankshaft/flywheel bolt.  I might leave a bit more than a flat clearance, but no more than 2 or 3 flats.

 

No sorry. You don't set the Flange Nut with clearance here, you wind it ON a further flat (or 2 or 3 I'd say should be OK).
 

 

I was meaning clearance off the end of the flywheel bolt but I can see how my comment could be misconstrued.

[Spider]

 

No sorry. You don't set the Flange Nut with clearance here, you wind it ON a further flat (or 2 or 3 I'd say should be OK).

 

I was meaning clearance off the end of the flywheel bolt but I can see how my comment could be misconstrued.

 

OK, gotya now.

 

To be honest, I wouldn't be too worried it that did occur as long as any such contact didn't impede the travel needed. The early Bolts did in fact have a raised pip on them to limit this travel here, but - and you might be on to it - this doesn't stop the assembly being thrown too far and the Crank Thrusts from being over loaded.
 

[postve]

I might get in trouble for this and if re removed I understand - Graeme, Spiderr,Soncar etc, take a look on my site and you will see vid showing how much movement of clutch

https://www.facebook...mibextid=S66gvF


I am going back out today to check as bleed clutch last night and fitted new return spring, plunger, bolt, arm, and have a new braided hose - will report back

Admin, I am sorry if I broke rules by posting my site and understand if this is removed