Well that's at least potentially something simple... but also a big pile of work. I can only imagine how frustrated you must be with this at this point, what a thankless old boat! Still, once you've fixed it you'll know everything there is to know about these gearboxes.
Thank you all for the kinda words of encouragement and faith!
I had exactly the same thought misteralz, but then remembered that the crank would only turn the torque convertor and without any fluid in the gearbox, and so far below the stall speed, it won't transfer any drive to the gearbox. As it turns out, the box did need to come out...
Some shiny bits have arrived in the post for my Mx5, so I promised myself I wouldn't start on the mx5 till I'd at least got the gearbox out of the Daimler, if for no other reason than all 4 of my axle stands are under the Daimler. This spurred me on to get on with it, so Tuesday night after work I thought I'd just unbolt a few bits in the last of the evening light, in preparation to pull the gearbox another day.
Some time later, in the dark and the drizzle, I've got the gearbox on the floor of the shed. Once I was lying under the car fighting with it, I just wanted done! haha.
This evening I went out to investigate the problem. I started by repeating the air pressure test.
Once again I can hear the front clutch piston move (there's a kinda squelch-thud as it slides back and forth), but turning the input shaft, I can feel that the clutch isn't locking up at all. Now I was actually quite reassured by this, as I've now found a 'problem', so if I can get the clutch to work with the air line on the bench, it should work when it's back in the car.
So first stage is to pull the front clutch out and check to make sure that the seal isn't all knackered up or anything.
Pulling the front clutch apart the first thing that strikes me is that it's odd that those clutch plates don't come al the way up that hub. I took them out and counted them... I've got 6 in there (3 fibre, 3 steel). That'll be the problem then. There's meant to be 8.
I'm not sure how I did this. I distinctly remember checking the manual and noticing that the rear clutch had 6 plates and the front had 8. I wonder if the piston wasn't all the way retracted when I assembled the clutch so it seemed 'full' with 6 plates in? The spare plates didn't worry me at the time, as when I built the rear clutch that also left me with a spare steel, so I figured it might be a difference between the several different gearboxes this rebuild kit covers. Maybe I was just tried and can't count to 8...
Anyway I quickly checked to see if the seal was sticking out/looking weird, like the old one was, but that looked fine. So I put the 6 plates back in, along with the one of the 'spare' steels and the 'spare' friction disc. Now this lined up neatly with the top of the central hub, which looks promising.
Popping the front clutch back in, I did the air line test and now the noise has changed. I can no longer hear the clutch piston moving, instead there is just a 'thump' and now when I turn the input shaft the clutch has locked and the output shaft turns. Wonderful.
So another lesson learnt is not to skip the test stages. Had I taken 5 mins to do these air line tests while I was assembling the gearbox, I would have spotted the problem and it would have only cost me 10 mins to correct it, rather than several hours that it's cost me this way round.
So problem solved, I reassembling the gearbox and it's now sat on the shed floor waiting to go back into the car, which will probably happen at the weekend.
All in all, a free fix and, once the gearbox was out, an obvious and straight forward fix. It's just cost me my time and realistically there isn't much else going on right now, so that's not the end of the world! Fingers crossed it works now!
Good stuff. We all make mistakes. It’s frustrating, but I suspect that you’re like me and would prefer the extra work to be the result of your own mistake rather than because you’d entrusted the work to someone else and they’d c0cked it up.
My worst worry about dying is my wife selling my stuff for what I told her it cost...
That was a mistake I could have done myself. Glad it didn't cost you anything more than your time at least. But on the plus side, it makes for very good reading for the rest of us! Really enjoying your thread.
That's actually a v positive problem to come across (I know there's the issue of having put the box in once and then having had to take it out....but still). You learnt something along the way and no further money spent, maybe a slight self-flagellation mentally for maybe missing a testing step but all in all - that's a really good outcome. Boxed isn't destroyed, you don't need another one, you can get on and fix the mx5 now guilt-free - all round excellent!!
Yes kevins, I breathed a sigh of relief as soon as I was able to find the repeatable consistent fault when testing wit the air line on the bench. Those intermittent faults where you can't find the issue are just the worst!