Clutch Adjustment

[csjcarolyn]

I hope this does not sound like a stupid question but how do you adjust the clutch. I know really but on my car if I move the adjusters so that I achieve a clearance at the clutch release fork then the pedal is half way to the floor. If I adjust the clutch so the brake and clutch pedals are nearly level I have no free play at the clutch fork!

If I pull the clutch pedal backwards [towards the driver] the pedal comes back several inches, it seems as if it will keep going round!

With a "normal" car the clutch pedal comes back to a limit stop and about 1" of free play can be felt at the pedal if the clutch release arm adjustment is correct.

What to do, if I have the pedals nearly level I am not confident I have cleanace at the release bearing?

[Dane_Rescueman]

Re: Clutch Adjustment

Hi Roger. I have the Cortina system which I shall chat about. I know of the Sierra system but have never tinkered with that automatic adjuster system.

At the RH lower forward of the bell housing you can see where the cable enters the housing to operate the clutch fork. The end of the outer cable is threaded and should have two nuts along it. The nose of the threaded portion enters the bell housing via a nylon bush. I don't have much luck adjusting the clutch using the pedal height calcs as in the Cortina manual (Haynes) as the Marlin pedals seem to be different. What I do is loosen the lock nut which is the one furthest away from the bell housing I then tug on the outer until I feel the release bearing come in to contact with the diaphragm spring fingers. I then screw the adjusting nut to give about a 2mm to 3mm gap, hold this in position and tighten the lock nut. When the outer is released it moves back that 2 to 3 mm in to the bell housing giving a nice clearance from the release bearing to the fingers.
My pedal is not exactly in line with the brake and throttle but I'm used to it. You can make little adjustments to the previously mentioned nuts to lower or raise the pedal slightly. Beware that raising the pedal may cause the clutch clearance to reduce.
The pedals in the Berli are mounted on a substantial shaft with pathetic nylon bushes twixt the two. These wear horribly and can make adjustment difficult.
Where the cable exits the front bulkhead from the pedal box there is an arrangment of various washers and ferrules - mostly of Dagenham plastic. If these are worn or missing then the pedal will be low.
Out of interest, I bought a Cortinal clutch cable which was far too short. The next Cortina cable I bought was spot on. Not much standardisation there then!
As you can see the very simple Cortina clutch system is not as simple as you may think. Did you know that there were at least six different release yokes; irritatingly, all with slightly different geometry!

Your pedal will keep on moving up a fair distance as the nipple is not held in place by springs or anything. Thus the arm can travel along the inner cable whilst lifting the pedal.

(I did not want to say that your clutch may be worn or the release bearing has collapsed. That would be GB out I'm afraid)

Wishing you the very best of luck Roger!

[greyV8pete]

Re: Clutch Adjustment

Hi Roger. The Sierra uses a cable for clutch operation. I replaced three in the 8 years that I had mine! In theory it is self adjusting.

The clutch pedal carries a pawl that rotates around a toothed quadrant around which the cable passes. When the pedal is fully up the stop should contact the pawl and disengage it from the quadrant. In this situation the clutch cable will be fully released and the clutch will be fully engaged. As soon as the clutch pedal is depressed a short way the pawl will engage with the nearest tooth and start to pull the cable / disengage the clutch. This is a very simple automatic adjuster for clutch wear and cable stretch. There are no adjustment nuts on the Sierra cable, just a simple ferrule that fits through a keyhole slot in the end of the clutch operating arm.

The Sierra malfunctions that I am aware of are:

1) The Pawl is sticking in the pedal (weak or broken spring or lack of clearance causing it to bind) so it either doesn't engage with the toothed segment or does so at a different point every time.

2) The spring is partially broken giving the same symptoms.

3) The cable is sticky in operation so doesn't return to the correct stop position every time.

If you have this set up try a bit of WD40 on the pawl and toothed segment bearings first and see what happens.

If your pedal doesn't return to a positive "stop" then it sounds as though the stop itself is either wrongly adjusted, missing or broken. Peter.

[James]

Re: Clutch Adjustment

Hi Roger!
I too have a Cortina system. I made a an angle iron with oblong fixing holes similar to the one for the brake light switch. In the place where the clutch pedal butted against the angle iron I drilled a hole in the angle iron and inserted an M6 bolt from the front with a nut for and aft. This made it possible to slide the angle iron back and forth and adjust the bolt to get the same pedal position as the brake pedal (the bolt is adjusted to limit upward movement of clutch pedal). I then adjusted the clutch cable as described by Dane
James

[csjcarolyn]

Re: Clutch Adjustment

Thanks for your replies and of course the way Dane and James said to adjust the clutch is the way I have done so for in past. I am intrigued as to why the clutch arrangement is as it is here, why is no limit stop fitted in the first place? If I adjust clutch clearance in the normal way the pedal is half way to the floor and the clutch does clear correctly!!!!!!!!!!!!!!!!!

Thanks again. Roger