Friday, June 13, 2014

Spare Engine - Flywheel Fun!

In an attempt to gain some experience of how the A-Series engine works, I bought a knackered engine for the princely sum of £10. Although the block is cracked and some parts were missing, it was ideal for taking to bits and learning what's what.

In the previous post I had taken the timing gear apart, but now my attention is focused on getting the flywheel and its housing off. This time I decided to do some research beforehand and found 'how to' guides on the internet and also some helpful videos on YouTube. So I went into this one armed with a bit of info, that's not to say that I didn't have my fair share of disasters and frustration.

The outer housing, sometimes called 'the wok' was just a matter of undoing a few bolts and taking it off, so not really worth bothering with here, the main fun starts with what lies beneath...

So what you might ask is beneath 'the wok'? The clutch of course! And when it comes to clutches, they seem to come in two flavours. There is the Verto and the preVerto. I'm not going to go into the differences here as a quick internet search will do that job. But needless to say, I have the verto type.

Verto Clutch

The first thing to notice is that there are three threaded holes that are there to accommodate a clutch puller. A clutch puller is one of these tools that I have an aversion to buying on the grounds that it is only used once in a blue moon and therefore not worth shelling out the cash. So, how to get the flywheel off without buying a clutch puller is the real challenge here.

The shaft that the flywheel is sat on is slightly tapered as is the inside of the flywheel. When the flywheel is torqued onto the shaft it is incredibly difficult to remove again. How this would be possible with the engine in the car is beyond me.

You will see above that I have inserted some bolts into the holes in the flywheel already. I had the great idea of using my trusty puller tool on the flywheel to pull it off the shaft. The first thing to do is to remove that hulking great nut in the centre. Unusually for the mini it is measured in metric at 30mm, I had to buy it specially. I don't mind buying sockets as they can be used for many things.

I undid the bolt a little and mounted the puller in place using the bolt heads to pull against.

Ready to go... I turned the handle of the puller and turned... and turned... and. well you get the picture. As it got harder to turn, I used a set of pliers to apply more torque until there was a nasty crack and the puller came flying off and I scraped my arm in the process. One thing you can rely on is that at some point your Mini will demand blood!!

But it seamed that this time, it had demanded more. As I picked my trusty puller tool up off the floor, I soon realised the source of the noise. My little friend was no more as it had snapped one of it's feet off :( To say I was gutted was an understatement. Everyone has a favorite tool and this was mine.


So with sadness in my heart, I once again looked online at the variety of clutch pulling tools available and came so close to buying one. I looked at one from Halfords for about £20. I know that's not too expensive, but it looked flimsy and not worth the money and I have my principles. So I closed the laptop and got busy finding a solution to the problem, rather than buying one. It's what poor old Puller would have wanted!

I knew what needed to be done. I needed to pull on the bolts sticking out and push on the centre nut in order to free the flywheel, but how. A scout around the shed came up with nothing at all. So I has a look in the cellar where I found my salvation in the form of a dumbell weight plate of all things!!

If you are a professional, I'd turn away now as the following paragraphs details one of the most outrageous hacks I have performed to date.

My idea was to drill holes in the plate that match up with the holes in the flywheel and use bolts through the plate into the flywheel. This way I could turn the bolts in turn and it would push on the centre nut to pull the flywheel off the shaft.

It was perfect except for the fact I needed to put 3 holes through a cast iron weight plate with a crappy drill and blunt drill bits and more importantly, the bolts were not long enough for the idea to work. Luckily I live not too far from a bolt supplier, so a quick trip there supplied three 90mm long bolts for next to nothing. Now just the small problem of those three holes.

The first problem was to locate where the holes would need to be on the plate so that they would align with the holes in the flywheel. I thought about measuring, but in the end used Blu-Tak. I attached a little Blu-Tak to the ends of the bolts that were in the flywheel and just stuck the plate in place and transferred the Blu-Tak to the plate. This left an impression of the head of the bolt in the correct location.

All I had to do was drill the holes in the places the Blu-Tak dictated. This would have been easy enough if I had a half decent drill and some good bits. But as mentioned the bits I had were utterly blunt so I started out drilling with the smallest bit I had and worked my way up the sizes.

It took forever, but eventually I got there.

And once the holes were big enough, it was bolted into place on the flywheel.

The picture above shows that the central nut on the flywheel was undone about half way to make it stick out. With the plate in place and the flywheel locked with some old wood, I used my breaker bar and a socket and went around the three bolts in turn giving them a slight turn trying to keep the tension as even as possible as I went. According to the Haynes manual, it is important that piston one is at TDC while doing this.

After about 3 goes around, I could tell that the flywheel was coming loose as it got easier and easier to turn the bolts. I had read that sometimes it goes with a bang, but not in my case as it just eventually came free without so much as a squeak.

With the flywheel off, I removed the C-shaped washer. The reason for setting piston one to TDC is to ensure that it is facing down. If it is facing the other way, it might slip down and get in the way when pulling the flywheel.

Then slip off the rest of the stuff. I don't know what it is called, it's just stuff!

Now the final part of the housing can be removed from the engine, there are several bolts behind the clutch with locking tabs and many others around the outside of the housing also. Once they are all out, I used a leather mallet to tap the housing free from the engine.

Sweet victory at last! Removing the flywheel is a major achievement and one made even more so by inventing my own tool and tainted a little by the passing of another. Sorry Puller.

Should I have bought the proper tool? Probably yes is the answer, it would have been a whole heap easier, but where's the fun in that? Plus I would have been left with a clutch puller that would sit in the shed for years unused, but most importantly, it's just not the 'Have a go hooligan' way.

Now that the flywheel housing has been removed, it has revealed a tantalizing array of goodies to investigate, but they are for the next blog entry. I think that is enough for now, you can have too much of a good thing you know!

<Next Post> - 'Spare Engine - Oil Pump Inspection'
<This Post> - 'Spare Engine - Flywheel Fun!'
<Previous Post> - 'Spare Engine - Timing Gear Removed'

For updates, stick a 'Like' on Wayne's Mini Progress facebook page.

No comments:

Post a Comment