New member hello & APD rebuild

[Goldnrust]

I probably should have been finishing off the brakes... but I've got side tracked by an empty work bench, now the majority of the suspension and brakes are back on the car, and could not resist starting on the gearbox.




When I initially drained the gearbox, all I got was water, no oil. So I presume the oil had been drained at some point previously, this left me a bit worried. I had liberally sprayed it down with WD40, but I still feared for the bearings and other components that were hidden out of sight. As you can see above, it didn't look pretty in there, no carnage to see but plenty of old fashioned dirt.

With some guidance from the helpful article on the Cornwall Austin 7 Club website, I had the gearbox stripped down with relative ease (not withstanding the evening when I'd misread the instructions as I was trying to do this at 11:30pm after a busy day!).



Inside the case looked even more dirty and I seem to also have a collection of spring washers! I wonder when those were lost, a while ago I bet as some were buried under the dirt, not just sat on top.



The gearset looked equally grim, though after a bath and a scrub was looking much better for itself. I think that layer of old caked on dirt and oil had actually protected all the steel parts from the water and there was really no corrosion to be seen anywhere inside the gearbox, which was a huge relief. I'm not hugely experienced with assessing synchros, but they didn't appear to be bottoming out, and there was no sign of rocking when the two tapered pieces were held together, so I believe that's all looking promising!



Though initially feeling a bit rough, after a thorough clean up I was happy to reuse the bearings.

While cleaning I made the mistake of pushing down a bit hard on the 1-2 sychro assembly, and it popped apart, with 6 spring loaded ball bearings flying across the shed in opposite directions! I found 5 of them, but the 6th was nowhere to be seen. Helpfully they appear to be standard 1/4" ball bearings and I had a plenty of those left over from overhauling my BSA, and some with some fiddling and help from a jubilee clip, I was able to get it put back together!



The inters haft bush was swapped out for a bronze bushing replacement, as I believe is common practice.

I also discovered a broken detent spring, on the 3-4 shift fork. Due to the sideways load applied by the helical cut gears, this would have likely had the car popping out of 3rd, which I believe is not unheard of with these boxes. I fitted new detent spring and balls to all 3 shift forks as a precaution.



I considered trying to convert the oil scrolls on the input and output shafts to modern lip seals, as suggested in the Cornwall A7 club article, but I decided in the end to pause on that for now. I'm still a beginner on the lathe, a mistake would be difficult to fix and I also don't want the project to 'creep' any further than it is already doing. I'll see how big the puddles are under the car and decide if I want to have ago at it another time!

Anyway, now I was ready to reassemble with some new gaskets, which was fairly straight forward. Looking much cleaner in there.



And finally reinstall the clutch release bearing, which had been cleaned and packed with fresh high temp grease, and installed the clutch fork with new taper pins.



Excellent. I should get back to rolling about on my back under the car dealing with the brakes shouldn't I... but there's a clear bench again now and the engine sat there on the floor just waiting for some attention...