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TR4/4A TR4A Clutch adjustment question

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Zimmycobra

Zimmycobra

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Help! I am now very confused. Here is my situation. I just restored a 1965 TR4A IRS. Not having any faith in what was there before, I rebuilt things as I could find from research and the Moss catalog. When it came to the clutch slave cylinder, I rebuilt the cylinder with the correct kit. When I reassembled the clutch and slave, I added the external slave return spring as shown in the Moss catalog. In reading posts here on this forum relating to the slave cylinder and its adjustment, I learned that starting with the TR4A, the external return spring was no longer used due to the internal spring of the cylinder. I took off the external spring this afternoon.

My system has the adjustable clutch pushrod. From the factory manual and the posts here, I believe that I understand that I should loosen the lock nut, turn the pushrod so that there is absolutely no play between the piston and the yoke, set the slight gap between the locknut and the yoke, and then screw the rod out until the nut hits the yoke and then tighten the nut. This will set the proper TOB clearance and the internal spring in the cylinder will then self adjust.

If that is correct - here is my major question - what is the lock nut spacing? I have a shop manual that states 0.1". I believe that several posts here also state 0.1". I also have an older 1974 Autobook Owner's Workshop Manual that states it should be 0.010". My personal feeling is that the 0.1" is too large. It causes what seems to be too much play. Can someone please verify the correct setting for me. Thank you all in advance.
 
0.1" is indeed the factory setting for earlier cars with Girling hydraulics. I'm not sure why the factory made it so large; probably to be sure it didn't close up between service intervals. (It goes down as the friction plate wears, and if it ever reaches zero the clutch will likely start to slip.) No idea where the .010" figure came from (same number is in the Haynes), but it pretty clearly is incorrect, IMO.

But for the 4A-6 setup, the freeplay shouldn't matter. The spring inside the slave is supposed to hold the piston out against the pushrod, so there is effectively no freeplay at the slave, regardless of the adjustment.
 
Thanks, Randall. The more I thought about it, the more I realized that it really doesn't matter due to the internal spring taking out the freeplay anyway. I will leave it at the 0.1" that I have now. I also realized that I must not have the piston pushed in when I set this because I can actually feel the freeplay at the slave. If the internal spring is working, there should be no free play no matter what the setting is. I need to look at this a little more. The clutch does work - actually does disengage and let me shift, although closer to the floor than I would like. From the video on Moss, I may still have some air trapped in the slave cylinder. I will try their bleed method to check this out as well.

Thanks again for the input.
 
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