Wednesday, December 17, 2014

Clutch and Flywheel Check

<This post is part of the 'Winter Project 2014/15 - New Engine Rebuild' project>

With the crank and new shells sorted, I now need to move on to the clutch. This is an area I didn't really understand until I took one to pieces for the first time and saw for myself what was what. Unfortunately the best clutch I had was the one I had to grind off the crank and as I did such a bad job, I kind of... well... totally wrecked it - (read about that fun here). This leaves me with the one I took from the earlier engine, which while is still intact, does look a bit worn and tired. So in this post I will be assessing what can be salvaged and what is scrap.

Verto Clutch Components
The type of clutch that we are looking at here is a verto type and consists of a flywheel, friction plate and a pressure plate. Starting with the friction plate, I can see staight away that compared to pictures of new ones on Mini Spare's website, it's really worn down. I was going to change this as a matter of course anyway.

Also looking at the pressure plate, I can see the friction surface is worn to the point that there's a bit of a lip. I looked into getting the surface machined flat again, but it's not worth it, so I will renew it.

When I looked into getting the new parts, I found that they come as a kit, which is handy. Well it would be except every kit I saw, no matter who supplied it came minus the centre boss. Normally this wouldn't be a problem as you would just unbolt your old one and use that. However the selection of centre bosses I have available isn't too good. There is this one...

Hmmm, let's face it, the damage is a bit more than cosmetic there. So that leaves me with the one I took from the first engine strip. Although it's intact, there are some rather knarly marks on the inside surface.

I'm guessing it's probably fine to use but I would worry that it may not sit true on the crankshaft, so I may look at replacing it.

The last thing to check is the flywheel, of which I have two to choose from. One of them has a slightly better friction surface than the other, so I was going to use that one. That is however until I noticed that the teeth around the edge were different to each other. This needed to be looked into.

129 teeth v's 107 teeth

After an hour or so digging around the internet to research the problem, I found that the difference is due to which type of starter motor you wish to use. The flywheel on the right has 107 teeth and is used with the earlier inertia starter motor or Bendix-type starter as it is sometimes called. The one on the left is a later type flywheel with 129 teeth and is used with a pre-engaged starter motor. As I intend to use a pre-engaged started, that pretty much makes the decision for me. Unfortunately this is the one with the poorer friction surface, but I think it will be fine once it is cleaned up with a bit of wet and dry.

So where does that leave me, well it leaves me with a shopping list for a 180mm clutch kit which comprises both friction plate and pressure plate. Possibly a new centre boss, depending on how I feel about the one I have and a flywheel that will clean up and be useful once more.

Best get shopping...

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

No comments:

Post a Comment