Clutch worry.

[genneton4]

Can somebody put me right please ?

I have a '68 1.5 coupe (not 2+2). Imported from the US.

My clutch bites quite close to the bottom of travel. Maybe just a tad below halfway (not slipping at all).

I converted the car from left to right two years ago myself. I used OEM clutch master cylinder and slave cylinder. The clutch cylinder is the one without the return spring.

The reason for the query is that .. is it something I have done wrong with my ham fisted work or is the clutch worn.

Some say clutch bite high is wear. Some say clutch bite low is wear.

The clutch is 20,000 miles old.

Mega money for a clutch replacement. I just don't have the room or height to do the job myself.

I am thinking :-

1) Is the slave cylinder arm length wrong. (I have maxed it as far as will go).
2) Is the master cylinder arm length wrong.
3) Did I do something wrong in the pedal enclosure on conversion.
4) Bite the bullet and spend £3 - 7K at least for a clutch.

Input from sages appreciated.

Keith - Notts

[mgcjag]

It's always best in my opinion to fit an external spring on the slave cylinder to keep the thrust bearing off the clutch and prevent wear....you need to first check the slave and pushrod and adjust as per the service manual....there is a hole in the bottom of the bellhousing if you look up in there you can see the thrust bearing and see how worn it is...

[rfs1957]

If the clutch itself was slipping, and NOT just because it was under permanent pre-load through bad adjustment, then you would need a new one.

But it isn’t, so I think the answer is that you don’t.

If the clutch release bearing was very worn, but still functioning correctly, you could end up with the excessive pedal travel you refer to.

You ought to be able to compensate for this wear by “lengthening” - either by adjustment or substitution - the operating rod that sits between the release fork and the slave cylinder.

I would remove the clevis pin, use the operating rod to push the slave as far up its bore as it will go (equates to Steve’s spring) whilst applying gentle pressure on the release fork (to bring the carbon bearing into contact with the clutch) and assess what gap you’ve got between the eye on the rod and the holes in the fork.

My guess is your operating rod is too short.

Easy enough to make one of the appropriate length ?

Probably just a bit of 5/16 bar with a UNF thread on the end.

Please let us know how you get on, very often these sort of queries are left hanging in mid-air and when we’ve given you the wrong advice we like to be corrected

[tim wood]

As part of this does anyone know where the special clevis pin with groove for the external spring can be obtained ?.
It’s on the SNG site as a kit but not listed separately.

T8m

[mgcjag]

Tim..off topic but the last one I got was on ebay...but search for the Jag part number to find one https://www.englishparts.com/products/J ... 27327.html

[mgcjag]

And look here for the clip for the pin viewtopic.php?t=16490

[genneton4]

Just resurrecting this thread from September if I may.

Tried to live with the pedal biting at the bottom and it's still annoying.

I agree that I could need a longer clutch master cylinder rod to bring the clutch up to be level with the brake pedal.
However, there is a spacer C31725 or C27160a on the pedal housing (between the master cylinder and pedal housing).

Could I remove this ? It looks about the distance I need (11.4mm).

Thanks - Keith

[bitsobrits]

Your earlier description of the bite point being just below halfway seems in the normal range to me. That said, I fiddled with the actuating rod length to get my pedal where it seemed right for me. My car does not have a spacer, though I'm contemplating adding one (1/8"-1/4") to lower my pedal. Spacer thickness change to pedal location change is not linear-it varies with the pedal leverage ratio.

So you can remove the spacer, but note the pedal height will now be higher, and if you try to lower it via a shorter actuating rod you may then not have enough pedal travel to fully actuate the clutch.

In any case I would recommend you buy/fabricate an adjustable rod as you will still need to adjust the rod length to get your preferred feel.

[SimonBrown]

I had a new clutch fitted to my Series 2 back in 2015, 3000 miles ago. The new clutch always had a low bite point, difficult to engage first gear etc. But not actually dragging. Tried all the usuals, clutch slave, bleeding, operating rod etc. all to no effect.
I recently and reluctantly removed the engine/gearbox and found the new clutch pressure plate was slightly out of shape.
Fitted another new clutch and the issue is completely resolved.
Apparently there were some faulty Borg and Beck clutches around this time and mine would appear to be one of them.
I hope yours isn’t the same, but it really isn’t that difficult to do the job yourself
Simon

[Paul bow]

As mentioned it’s not a difficult job to do yourself but definitely one you’d rather not do. Anyhow the 3k+ you have been quoted seems strong to me.. I had a clutch release bearing give up on a rolling road session at Northampton motorsport, 20 mins in, just exploded.. anyhow that’s a different story, I left the car at the garage and had them do the job, that was around this time last year cost me a very reasonable £1250, so factor in inflation and the fact I spent a lot with them I reckon you’d be circa £1600ish..
Can’t speak highly enough of them, fingers crossed it’s just an adjustment issue ..
Good luck

[david.coan]

My 1968 s1.5 clutch peddle bite had moved downward and it became increasingly difficult to select some gears when hot, mainly first. It’s been a gradual deterioration over a long time so i had not really appreciated it until recently. My problem has turned out to be the master clutch cylinder seals failing, allowing some fluid i think incorrectly to go back up into the reservoir on clutch operation leading i think to weak pressure requiring more peddle depression to get enough pressure to operate the slave. Just completed the job today. It transformed the clutch operation back to how i now realise it was a long time ago.
My clutch master cylinder has the spacer, i would not easily be able to leave the spacer out as the studs the cylinder locates onto are not fully threaded so ‘lots’ of washers or similar would be needed to get a bite fit on the nuts if the spacer was not there.
My new oem master cylinder from moss came with three different length operating rods, the one pre fitted was the correct length when using the spacer, two alternate lengths for other car types i guess.
Hardest part of swapping the master cylinder? Getting into the footwell to remove and replace the split pin on the peddle….small child helper would be ideal..or maybe remove steering wheel. Workshop timetable suggests 1.5 hrs job….more like 5hrs for me.

[genneton4]

Thanks for all input - problem now solved.

Just for completion. Removing the spacer was far too much.

I removed the M/C. I adapted the longer generic rod that came with the oem M/C. I cut off the fork from the original M/C rod and made an adjustable rod. Works a treat. Wish I had done it originally.

As the previous post said - removing and replacing the split pin and clevis was a pain, you need a lesson in gynecology ... but worth the effort. (and a cricked neck) !!

Keith