Clutch Adjustment and Cable Replacement

By David Jones

Removal of Inner Cable and Bowden Cable

Adjusting the Clutch

Identifying Your Clutch Cable

Identifying Your Clutch Cable

Before we get in to the nuts and bolts of adjusting and/or changing clutch cable and associated parts we should first ascertain which clutch cable version you have.

There are four cables between the A, B, and C cars and two Bowden cable tube types as well as different cable ends and lengths. The Stoddard catalog is very helpful in determining which is correct for your car but beware of changes that could have been made and check what is in the car before buying the spare as modifications can and are made which will cause problems if the right parts are chosen and you find that someone has modified your car to accept an earlier or later cable.

All have both ends threaded but different diameters on some from one end to the other.

Stoddard lists the following part #'s:

For pre "A" cars, cable and housing part #. 356.23.058. 2085mm long with 6mm ends. For the early 356A P#644.23.208.1 2057mm long with 6/8mm ends

For the late 356a and all the B T5's and the early B T6's P# 644.423.401.00 and is 2015mm long with 6mm ends

For the last T6 B's and all the "C"s the P# is 644.423.401.01 and is 2025mm long and has 6/7mm ends.

The two Bowden tubes or clutch cable housing are P# 644.23.209375 mm long for the 356A

For the B and C cars it is P#695.423.421.01 and is 490mm long.

Adjusting the Clutch

There are a multiplicity of adjustments and they are as follows.

The easiest place to adjust the clutch cable should be at the pedal end. Remove the carpet, throttle pedal and floor board, in that order on the driver's side to get to the cable adjuster nuts. There are two nuts, one locks against the other. Loosen the nuts and proceed to adjust by tightening the inside nut on the threaded portion of the clutch cable until the required free play is attained (0.8" to 1")

Usually the reason for making this adjustment is because the cable has stretched (if this is the case then order a new cable because it is telling you it is not long before it breaks) or the clutch disc or the clutch disc and pressure plate has been changed. If the clutch disc or disc and pressure plate has been changed then there is another procedure that should be followed to get the correct clearance.

While the engine is still out you should set the end play at this time by measuring the distance from the trans flange to the throw out bearing and making that distance about 40 thou more than the distance from the mating surface of the engine to the mating face of the clutch disc. This adjustment can of course be made at the trans end of the cable, as it is easy to reach and work on while the engine is out.

Because of the mechanical advantage gained by the leverage multiplier of the foot pedal that 40 thou is the equivalent to the 0.8 to 1.0" free play at the pedal. While we are at this end of the car we can compare different cable ends. On the earlier cars there is just a threaded rod that fits through the hole in the end of the clutch-operating arm. Moving a locked 14 mm ATF x 6, 7 or 8 mm nut on the threaded portion makes the adjustment. The lock nut is an 11mm ATF.

Later cars have a clevis pinned end but this clevis pin is attached to the clutch cable by means of a threaded rod as before. The problem with this later one is that the clevis wears a ridge and is almost impossible to remove after a few years due to the ridge and rust. I have found that cutting it off is very effective in reducing the amount of frustration inherent in this job. Nine times out of ten it has to be replaced anyway.

There is a quick and dirty way to adjust the clutch free play and that is by using the Bowden cable adjustment. Care should be taken using this method so as not to reduce the "bow" in the cable to the point where the clutch will shudder on take up. If a straight line is drawn through the ends of the Bowden cable there should be at least 3/4" bow to eliminate clutch shudder.

The Bowden cable portion is easily adjusted using a stubby 17mm and 19mm wrench while lying on your back under the car with your feet out the back end. [With the car safely jacked up! See the jacking article for details.]

Once the pedal free play is set the clutch pedal throw should be checked to make sure that it is not pushed "over center" There is a stop above the clutch foot pedal arm which should be placed such that the clutch pedal only travels about one inch past the point where the clutch disengages to prevent damage to the TO bearing and pressure plate.

The arm, which swivels on the floor shaft, has a clamp on the end through which the clutch pedal shaft fits. This can be used to change the position of the clutch pedal if needed for those drivers with extra leg length.

Removal of Inner Cable and Bowden Cable

I have found that the easiest way to remove the cable is from the rear [see photos below]. Remove the nuts on the threaded end at the pedal and pull the cable through. This can be accomplished by lying on your back under the car with feet out the back. Grasp the Bowden tube firmly and pull it toward the back of the car. The inner cable will come with it. Once you have enough inner cable pulled through it gets easy and all the inner cable can be pulled out. The Bowden tube can then be slid off the inner and out of it's locating arm on the trans leaving the inner still to be pulled out from behind the clutch arm. This is easier than trying to remove the two nuts from the threaded end if they have been on there for any length of time.

On the late B T6 and the "C" you have the extra clevis with 6mm threaded end and the clevis "bolt" (more of a spring loaded pin actually).

Again if this has been on there any length of time just cut it off with a file, hacksaw or dremel tool as it will save a lot of time and frustration if it does not come off in a few minutes.

Replacement as they say is the reverse of disassembly. One helpful trick is to jam the clutch arm forward against the TO bearing taking up the free play so as to make it easier to run the nut up the thread once the cable is through the clutch attachment point at the pedal end. Before the final adjustment of the cable is made make sure you have the Bowden tube adjusted with 3/4" of bend and that it is located properly at both ends. It goes OVER the throttle bell crank pivot.

Technical advice given on these pages is provided free and without warranty. The user of information presented on these pages assumes all responsibility and liability in its use. We're not lawyers, we're car folk, just sharing our experience. Be careful, use your head, have fun.

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