Very productive day in and under ELT 44C.
First off, thank you Harvey for your how-to guide, which was extremely useful.
Pedal heights were too low, so I fixed that. Then I discovered that the clutch pedal was reaching the end of its rather short travel well before the stop bolt on the floor. Next, the release bearing's actuating arm wasn't angled as it was supposed to be, but vertical. So off it came, managing to avoid dropping the nut in the bellhousing. I epoxied the nut to the arm to prevent disaster on refitting, and refitted the arm one spline round from where it was.
Time to enlist the help of Mrs S. Even with the pushrod held in by just two threads it still wasn't possible to get the pedal to touch the stop bolt before the slave piston touched the circlip. Master cylinder fault, allowing insufficient travel? No - I pushed the slave piston right into the cylinder, pressed the pedal and there was full travel to the stop bolt. And, in doing so, got air in the system. Mrs S was cajoled away from trimming the rain forest that our garden seems to have become and back onto clutch-pressing duties while I bled the system.
Still not right. Conclusion? The pushrod was too short. Why that should be, I don't know. So I made up a longer one from a spare bolt, tapping a longer thread and rounding the end, and tried that. Success! All now seems to work perfectly - nice biting point, no drag, no funny noises, lovely snickety gearchange. And much relief all round.
While under there I also realigned the engine and gearbox so the spring at the back of the gearbox is vertical instead of leaning at a drunken angle, and the snub rubber is as central around the bar as I can get it. I'd like the back of the gearbox to go up another 1/4in but I don't see how it can. The tie rod at the front of the engine was loose as I repositioned the engine slightly on its mountings, so that's not forcing the gearbox down. Anyway it's as good as I can make it.
I also think I might have discovered the source of a bang at the back when taking up drive smartly, which might be tied in with a slight tremor (not quite a judder) when reversing slowly with the clutch slipping - the tremor seems to cycle with the slow rotation of the propshaft. Should it be possible to heave the diff extension, where the propshaft enters, up and down quite easily against the mounting? Or has the mounting come to bits? It does seem to be very softly mounted at the moment.
John