I have dismantled my M20 engine in order to do a full restoration.
I have "splitted" the crankcase and the drive side case came out easily. Now I have the timing side case left connected to the flywheel. I tried to hammer gently the mainshaft with no success. The bearing holds the case and the mainshaft, and does not fall apart.
Does anyone know how should I remove the flywheel from the case? The manuals say both parts should be removed easily…
I thought putting the whole assembly in the oven and heat it. Than try to pull it out again. Any suggestions?

Thanks,
Nimrod

email (option): nimrod@kaufmann.co.il

Have you removed the gears from the end of the shaft? if you have, there should be no reason that it should come out. You should support the crankcases on 2 blocks of wood and then replace the nut on the end of the shaft to prevent the thread from getting damaged whilst you hit it with a copper/ hide mallet, or an aluminium drift with a normal hammer.

email (option): davmax@ntlworld.com

Hi Nimrod,

I had the same thing with a motor which was standing in bad conditions for some 60 years,
And took it out with a large extractor. I think that this is the best way, as then it is balanced.
If you do it, first, insert a screw into the flywheel's mainshaft, in order not to damage it with the extractor.
you really just need to break the first resistance and then it would slide out.
"Bizbiz" would usually use a crowbar between the flywheel and the body...

The other option is of course as Dave advised,
which usually works great.


Cheers,
Noam.

email (option): noam10@gmail.com

I wouldn't recommend hitting the shaft on the end...with or without the nut. Quite a lot of force is required to drive out the shaft and if you hit it 'out of square' you'll damage the shaft/thread/nut....

Occasionally the shaft/bearing on the timing side will be hard to remove if an engine has been left standing as Noam describes....

I first remove the crankshaft pinion..Then rest the cases on some blocks so that the drive side of the crank is clear of the floor/bench surface...
Next I use a tool that I machined for this purpose...

Basically it is just a piece of bar that has an O.D. just less than 7/8" (.875") diameter...This is then drilled out to a 1/2" (.500") clearance size so it fits over the shaft where the pinion was removed...It must have sufficient depth in the hole to allow the end of the bar to rest firmly against the shoulder where the diameter of the shaft increases to 7/8".

Now you should be able to drift the shaft out using the tool and a mallet or hammer....Ian

email (option): ian@wright52.plus.com

Ian, do ya have a picture of that gizmo?

I do normally.use a hydraulic press, I'm just looking for the practical solution for him, it may not be that tight in there and just one swift tap with a hammer may get it moving![8-)

email (option): davmax@ntlworld.com

Thank you all for the prompt reply and advice
I have used a drilled bar rest against the shaft shoulder. Placed the case on a wooden block and hit it with a mallet. Nothing! Then I tried the sledgehammer (which I promised myself not to take out of my toolbox throughout the entire restoration...).No success
I think I better look for hydraulic press. I am afraid that hitting harder than that may damage the case.

Thanks,
Nimrod

email (option): nimrod@kaufmann.co.il

Sledgehammer!!!???

Sorry, I probably used the wrong term. English is not my first language
Nimrod

email (option): nimrod@kaufmann.co.il

If it was bigger he probably meant a lump hammer, about the size of a small sledgehammer but with a short handle.....

Hi Nimrod,

Think I would try and heat up the crankcase a bit if I was in your position.

The inner bearings may be Loctited on the shaft and if so they probably won't go without some heat. You have a fair chance that the whole bearings are coming out of the case, but then your case is save and you can deal with the bearings in full sight.

Good luck, Michiel / NL

Agree totally...It's very easy to apply excessive pressure with a hydraulic press as you have no 'feel' at all...
I don't like the things and think they should be used with extreme care in some situations...
A large fly press is much better....

However, after the application of some heat it should respond to the drift and a hammer....
Don't forget also that the outer bearing (and crank etc.) can be driven out of the (heated) case using a punch and hammer inserted through the two holes inside the timing chest that are provided for this....Ian

email (option): ian@wright52.plus.com

Hi Nimrod,

I've mailed you.

If you want, and we are not too far, I can try to help..

Noam.

email (option): noam10@gmail.com