Engine stalls when I de-clutch

[jamesheath]

Arg....
I've finally got the rebuilt engine back in the car.
It started first time and sounds lovely (at idle at least).
When I first fired it up I had the back axle on stands, so tried all the gears and everything was fine.
Now it stalls as I depress the clutch. Even if I rev it I can't keep it going enough to get it in gear and move.
I've put it back on stands, but it's the same.
When on stands I note that the prop shaft is turning when idling in neutral, and it needs a good grip to stop it turning...

Since the first run I've changed the gearbox oil (there wasn't much in there, have added 2/3 pint of SAE90), put a little more down the clutch release bearing tube and re greased everything....
How have I broken it??

[Ivor Hawkins]

No you haven’t broken it James, but get the SAE90 out of the gearbox, that will make things even worse! Make sure all of the SAE 90 drains out and replace with a small amount of engine oil...Straight 30 if the engine hasn’t been stripped and rebuilt or cheap supermarket 20/50. No more than just below the threads in the filler.

Next, check that the cutch is adjusted properly, take a look at the Cornish A7 site if you have a four speed, there’s some great guidance there.

Once the gooey ail is out and the clutch is adjusted, that should have you sorted.

["Slack Alice" Simon]

I think you should take the flywheel cover off and check that it doesn't move forwards when you push the clutch pedal.

[jamesheath]

Thanks both - apols for the delay in replying - I posted in haste as I was leaving on a trip, so I can't check anything right now.
I had thought that 90 was the right oil, although standard engine oil was acceptable. I'll switch back. I also thought that 2/3 of a pint was the right amount - that's well below the threads of the filler. I can see how the thick oil is likely causing the prop shaft to spin in neutral.
Clutch adjustment looked tricky - it seemed to involve heating and then bending all 3 levers.... The clutch did seem to work OK on first assembly.
Simon - I'll have to check when I get back - If the flywheel is moving forward, does that imply the crank is pushing forward too? That's worrying!!
I'll let you both know what I find out, though it'll be a little while sadly.

["Slack Alice" Simon]

It shouldn't move forwards or back, any movement implies something wrong with the main bearings or their housings, or a loose flywheel.

I suggested it because it is an easy check to do.

Read up about clutches, there are other things to do besides bending levers.  Eg. replacing levers and/or pivots.

If appropriate, a standard bodge is packing the cover plate away from the flywheel with washers, which works for a while.

[jamesheath]

So I'm back at home and looking at this again.....
I think It's kind of getting there.....
I fitted a proper lip seal to the rear main bearing - this pushes the securing bolts further out.
The bent lock washers on these appear to be right next to the flywheel (probably compressed a bit when I torqued up the flywheel).
The top two were accessible enough to bend them away a tad.
My guess is that the bottom two are slowly giving in, as the clutch no longer stalls the engine, and the level of drag is reducing quickly (I've only done about 2 miles)