Little white Eunos

Copying my posts out of the 'So what did you do...' thread here for posterity.

28/10/22

I'm still waiting for the new clutch slave cylinder to arrive so I was faffing with the exhaust last night. I'd tried to fit a new Jass heat shield, but one of the bolts sheared off in the manifold captive nut, and I couldn't get the remains out while it was still in the car. So I took it out again and spent a while drilling into the bolt to get one of those stud extractors in it. Eventually I just drilled through enough of it that I reached the other side, and used some brute force and ignorance to mangle the rest out. Then I did what I should've done in the first place and chased the threads with a tap. My manifold is missing the bottom right bracket that the heat shield has a hole for, so it'll only be held on with two bolts. The manifold that came attached to the spare engine was also missing the same bracket so I couldn't even just swap them over!

When I was test running the car to do the timing it was pretty bloody hot without any sort of heat shield, and the Jass one is just a shiny single skin piece of stainless steel, so I wrapped the manifold as well. Bit of a rough job but it should do the trick.


Oh and I noticed that my temperature gauge didn't move, even when the engine was hot. I swapped the sensor in the top of the thermostat with the original one, but I'm still getting nothing on the gauge. Any guesses what to try next?

31/10/22

OK, clutch slave replacement is done, but I got lost with where all the pipes went. It looks from the diagram like there's a whole load of unnecessary pipework between the master cylinder and the slave cylinder:

Before I do something silly, is there any reason I can't just replace all that gubbins with the braided line straight down from the master cylinder to the slave? I'm going to wish I'd done it while the engine was out, that's for sure.

01/11/22

Braided line went straight from the master cylinder to the slave, and I ripped out all the spaghetti so that cleaned things up a bit. Refilled will fluid, bled it out of the nipple....and there was absolutely no pedal resistance at all! Does that mean my master cylinder is now b0rked too?

02/11/22

I'm getting really fed up with it now. I finally found a position where I could see into the clutch fork-hole, and the fork is pushing the release bearing towards the clutch as it should. It just doesn't seem to push it far enough to move the clutch spring fingers. I took the slave cylinder off its mounting point, brought it up above the master cylinder, put the bleed nipple at the top and bled it a few times. I think the master cylinder is OK as it does get some pressure, and does push the fluid through to the slave. The pedal has a bit of resistance right at the end of its travel, but I still can't get the bleddy thing into gear with the engine running.

04/11/22

A few people have suggested that I might need to adjust the clutch pedal/pushrod position in the master cylinder, and I found some guidance on Flying Miata, so I'm going to give that a try next. A few other people have suggested that I've put the clutch friction plate in back to front, which I really didn't think I had until people kept suggesting it...

07/11/22

I got a sneaky hour or so in the garage on Saturday, and after doing my best contorsionist impression I fiddled with the clutch pedal position. Apart from scraping my knuckles, swearing a lot, and the blue plastic spacer thing disintegrating (after 30 years in service, not surprising), it made bugger all difference

The hole where the pedal pushrod goes into the master cylinder looks a bit rusty so I'm thinking of replacing the master cylinder as one last-ditch effort before biting the bullet and dropping the transmission. Even if it doesn't make any difference, at least I'll know all the bits have been refreshed at the same time.

08/11/22

Actually scrap that, I tried all the adjustment I could with the pedal and it still wouldn't work, so I've started undoing things to drop the gearbox. Got the propshaft bolts undone, though unsurprisingly after 30 years it's rusted to the flange of the diff. Nearly 4 months off the road now, and only 2 of those were doing the engine swap!

09/11/22

Made some more progress last night. Got the prop shaft out, took the slave cylinder off for the 7th time, and undid about half of the bellhousing bolts. A couple of awkward ones still to wrestle with but should be able to drop it next time I'm in the garage. I'm actually hoping that I did put the friction plate in back to front, because if I didn't, I have no idea why it's not working!

15/11/22

Took off the exhaust (again), undid the PPF bolts and some electrical connections, undid the last few bolts holding the gearbox to the engine, and waggled it off. Not gracefully as I didn't know where the centre of gravity was going to be, and I missed a cable off so that pulled out of its connector, but otherwise no big trouble.

Took the clutch pressure plate off, and I did have the friction plate on back to front. So it's really annoying that I've wasted a good month faffing about not being able to fix my mistake (and that the design is such that it *can* be put on back to front), but at least I know it's on the mend now.

21/11/22

Made some progress with the gearbox, after much grunting and faffing about with trolley jack, tow strap coming up through the gearstick-hole, wooden trolley and bits of 2x4, I got it in the right place to start doing up some bolts to the bellhousing. Hopefully finish getting it in the right place tonight, then do everything back up again, refit prop shaft and exhaust, etc. Had to re-make the connections to the reverse switch which got pulled out when I forgot to disconnect them before dropping the box last week. Have a trackday and 12 car rally both on 2 December so really want to get it working before then!

23/11/22

Took a while to work out why the box was fitting more closely at the bottom than the top, where the gap was so big none of the bolts would reach....the engine had sagged forwards so its rear canoe was sticking up. Quick jack under the front of the block to tilt it backwards, and it came together fine, along with a few stripped knuckles. Just got the exhaust bracket bolts and starter motor bolts to put back in around the bellhousing, then PPF, prop shaft and exhaust can go back on. Fill it with new gearbox oil, refit the gearstick and it should be good to go...

24/11/22

Well, as I often find, something that should have been simple took far too long. Was putting the PPF long bolts back in, they have a couple of captive nuts joined together which slide along the top of the PPF so they line up with the holes. However, the front one on mine seems to have somehow got bent upwards so the nut face is not flush with the top of the PPF. I spent well over half an hour trying to get the bleddy bolt to catch in the thread, but it just won't get to the correct angle. Is there a way to get those captive nuts off so I can straighten the plate the joins them together? Hopefully without having to drop the gearbox again...

25/11/22

I tried punching the pegs out from underneath but they weren't budging. I took the PPF off the gearbox and pushed it to one side so I could get a better look, and it really didn't seem to be too far off straight, so I used brute force and ignorance, and got them done up eventually. Also finished doing up all the bellhousing and starter motor bolts. So, left to do are: refit prop shaft, reinstall exhaust, reattach slave cylinder, refill gearbox/turret, refit gearstick and gaiters, and probably some other stuff I've forgotten. Should be back on its wheels next time I get out to the garage...

29/11/22

Nearly but not quite! Got the prop shaft in and done up, refilled the gearbox with oil (50/50 75W-90 and redline lightweight shockproof), reinstalled the exhaust, reconnected the speedo cable, checked the diff oil.

Stupid thing of the night, when fitting the prop shaft I wanted to be able to turn it to get at the bolts, and I thought it was in gear, so I chucked the gearstick in the turret to get it into neutral, without having done up the gaiter etc. So of course it twanged out with all the washers and bits flying around the cabin, and the nylon cup on the bottom of the gearstick was nowhere to be found. I searched on/around/under both seats, under the edge of the carpets, on the dashboard, on the garage floor, and eventually found it hidden in the turret oil. What a plonker.

So, just refilling the turret, fitting the gearstick, gaiters and centre console, and reattaching the slave cylinder to go. Then hopefully I can take the bloody thing for a test drive!

30/11/22

AAAAAAAAAAAAARRRRRRRRRRRRRGGGGGGGGGGHHHHHHHHHHHHHHHHHHH!

Finished putting the bits back together, put it on the ground, and IT STILL WON'T GO INTO GEAR! FFS.

It feels exactly as it did before I swapped the clutch plate around. The slave cylinder moves with the pedal, there's no air in the system, I just haven't got a clue what to try next

01/12/22

Thanks all, I'm going to try a new master cylinder first, as I don't have to drop the gearbox again for that. Other folks have suggested that I should have changed the pressure plate at the same time as the friction plate, so if changing the master cylinder doesn't fix it, that's my next port of call. The clutch was working perfectly fine before the engine went, and when I swapped it over to the replacement engine I thought that replacing the friction plate would be all that was needed, since the old one was fairly worn and it was much easier to replace while the engine was out. Looks like it'll end up being a replacement of the entire clutch system at this rate!

08/12/22

Changed the clutch master over to the new one, was surprisingly easy. Bled it OK, but it didn't make a noticeable difference to my clutch woes. I took the rubber boot off the fork hole and stuck a crow bar in there, and found it is possible to move the release bearing further than it goes with the fork and it felt like it must be moving the clutch. It just doesn't do it with the pedal, like the slave piston doesn't push it far enough. The clutch fork is quite loose on the ball but it is still attached as far as I can tell.

09/12/22

Having put a video of my slave cylinder/clutch fork movement onto the Mk1 Facebook group, someone else posted a video of theirs (thread is here, probably need to be a group member to see it). From what I can see, my slave piston is moving the fork the correct amount, but the other guy's fork is much closer to the slave cylinder 'at rest', so his piston is less extended before the pedal is pushed. This seems to be because his clutch fork end sits much nearer the front of the car than mine does. Not sure if that's all I need to do, sort out where the fork is sitting?

I've read a few posts on other forums where people have started it in gear and the shock has freed something up inside, but my car is facing into the garage, and there's not much room between leaving the garage in reverse and going through the wall of the neighbours' garage so I don't really want to risk it. Potentially could try pushing it out to turn it round, but I might not get it back in again as the drive is on a slope!

The new release bearing was the same as the old one, and of course I didn't take any pictures to prove that to myself, nor did I take any pictures of the innards after I took the gearbox off again, so can't be sure of anything anymore. I'm just about resigned to taking the gearbox off again and fitting a new pressure plate, as that's the only thing I haven't changed now!

13/12/22

I've ordered a new clutch kit (pressure plate, friction plate and release bearing) and started to take the gearbox off again last night.

Took off the exhaust, prop shaft, PPF front bolts and electrical connections as well, so after one 2-hour session I've just got the bottom two bellhousing bolts to remove and it'll be off again.

16/12/22

Today's clutch news: got the gearbox off again last night, and remembered to take some pictures this time.

Here's the one that didn't work (old pressure plate, new OEM friction plate):


The clutch fork doesn't appear to be damaged but it does go down at the end, is it supposed to be straight all the way along?


New clutch kit (pressure and friction plate) fitted. The torque spec for the bolts seems very low (22 Nm) but I went with it anyway. (And yes I realise there are no bolts in the photo!)

Hopefully will get it back together in my next session and see if it has fixed the problem...

20/12/22

I checked out the clutch fork, and compared it with photos of new ones, and it doesn't seem bent or broken, so I cleaned it up and put it back on the car. It is really loose on the pivot ball thing, but doesn't come off unless you spread the spring.

So I mated the gearbox back up to the engine (with new clutch) and the fork seemed to be exactly the same as it was before - waggling around and not contacting the pressure plate fingers until right at the end of its travel. Surely this can't be correct?

Another vid of the movement:

The ball pivot things appear to be a separate part so will see if I can find one to replace. The fork seems fine but maybe the spring has become too weak to hold it in place properly, so might try getting a replacement for that.

I haven't changed anything with the gearbox itself and it was working fine before, so I really think it's something to do with the clutch fork and where it sits.

The clutch fork isn't bent, and it's hooked up to the release bearing properly yep. The spring holding the fork to the pivot ball won't let the fork come off altogether, but isn't holding in there very tightly either.

23/12/22

So back into battle last night, I bothered to drain the gearbox oil before removing it again (spilt a load out of the propshaft hole last time, duh), and it was a lot more of a struggle to get it off the engine this time for some reason. I tried putting the engine at different angles, supporting the turret end of the gearbox at various heights, etc etc and eventually managed to wrestle it off. Having watched a couple of videos on the choob where people lay underneath and bench-pressed it up there I didn't fancy that, but on reflection it might not have actually been more effort!

Got the fork out, and the verdict is...

...looks about the same as yours Zed.

I have a hard time believing that the weakness of the little spring holding the fork to the pivot could prevent the clutch from working, but that and the pivot ball are really the only things left in question!

The one nightmare thought I have had is that since the replacement engine came off an automatic, maybe there's something different about the back end of the engine, but it doesn't look like it when comparing to my original manual engine, and I transferred the flywheel over and fitted a new pilot/spigot bearing. I will have a look for some guides of doing a manual swap on an auto car and see if there's anything I've missed there...

06/01/23

Was back out in the garage last night, trying again to work out what's going on with the clutch. I put the alignment tool back into the friction plate and it didn't go in very far, so I took the clutch off again. The splines of the friction plate were a bit chewed up, presumably from my attempts to mate the gearbox to the engine, so I put a different friction disk in and did it all up again. New clutch fork and dust cover coming from MX5parts and I'm going to give it one more try before admitting defeat and towing it to a workshop.

Anyone have any tips on how to be sure the shaft/splines have gone in properly before tightening things up? I've rechecked the clutch alignment after doing up the pressure plate and it seems good, but when it comes to wrestling the gearbox on it seems a bit random as to whether the splines will go in or not.

10/01/23

I put the new clutch fork in, and the new boot, seemed a lot more secure and the release bearing moved where it should do. So I took my time and got the gearbox back on, it went quite smoothly and I checked that the splines were in OK by putting it in gear, loosely fitting the propshaft and turning the engine a bit. Seems to have more resistance and better pedal feel. Won't know if it actually works until I've put some other stuff back on (at least the exhaust so I can start the engine), and if it doesn't, I'm going to give up and take it somewhere.

12/01/23

I got a load more done last night - finished tightening up all the bellhousing bolts and the starter motor, put the prop shaft back on and the exhaust manifold. I keep meaning to loosen up the bolts joining the manifold to the downpipe while the exhaust is off, as it's a beeatch to get to them when it's all fitted....but I hadn't so it went back in as before. At the moment I have to take off the whole manifold and disconnect it at the mid-pipe end so it all comes out in a 5 ft long tree trunk.

Need to refill with gearbox oil and then I can start it up and see if it goes into gear...

17/01/23

IT'S ALIVE!

All I had left to do tonight was fill the gearbox with oil and reattach the air filter thing under the bonnet, which is just as well as it's -2C here tonight. So when I put the key in and the engine wouldn't start, I was pretty much ready to sell the bleddy thing! A few minutes later I realised I hadn't reconnected the wire between the ECU and the spark plugs, and it started up OK 🙄 (all four wheels off the ground)
Then the acid test, with the engine running it wouldn't go into gear from neutral, so I stifled a cry and turned it off, put it in gear and started the engine while in gear, wheels spinning OK. So I turned it off again, put it in gear and started it with the clutch in, then dumped the clutch roughly, it made a bit of a clunk and then it all worked! So I can get into gear from neutral, and change gears again too. FINALLY!

Of course now I've got the car on a SORN with an expired MOT, so I can't just take it for a burn, but will at least need to take the long way to the MOT station to shake it down a bit after 6 months off the road. I'm now wondering whether it would have done the same thing 2 months ago when I first put the gearbox back on after flipping the friction plate around, but at least EVERYTHING in the clutch system is completely new now, down to the bleddy clutch fork boot.

24/01/23

All sorted, taxed, MOTd and insured

Can't believe it's been over 6 months, but at least I now know how to replace an engine, remove a gearbox and replace a clutch!