central bevel gear extractor

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guzzijake
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central bevel gear extractor

Post by guzzijake » Fri Jan 18, 2019 9:47 pm

Hi, I've noticed the meshing of this central bevel gear (the one on the distributor shaft) with the individual shafts is a long way out. Does anyone know where I can get a hold of one of these special extractors? Its referenced by part number 887130111.

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Craig in France
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Re: central bevel gear extractor

Post by Craig in France » Sat Jan 19, 2019 3:12 am

Hi Jake,

Bit confused .. That puller is for pulling the bearing bushes of the drive shafts - as illustrated and described here:
0111.jpg
Is that what you're intending to do? If so, I'm not sure it's gonna help you get a better mesh. The factory advise you to adjust the mesh between the bevel gears by using shims on the distributor shaft- see below:
0111a.jpg
But maybe I'm missing something?

Craig

guzzijake
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Re: central bevel gear extractor

Post by guzzijake » Sat Jan 19, 2019 4:44 am

hey craig, yes that the one, the central conical bevel gear. I thought I needed that extractor to pull it out from inside the distributor hole and put in some shims. How does one go about getting a proper mesh between the three bevel gears? Mine is a good millimeter and a half out, the central gear is only just touching the upper half of the teeth on both pinions leading to the top ends! I could probably use washers instead of shims...

wdietz186
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Re: central bevel gear extractor

Post by wdietz186 » Sat Jan 19, 2019 7:11 am

When checking the mesh you do need to check it at the ground areas on the gears, it's a flat area that the factory did when the gears were matched. I had to replace one of the cyl. drive gears once, it is a very time consuming operation!

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Re: central bevel gear extractor

Post by guzzijake » Sat Jan 19, 2019 11:49 am

please dont tell me i need to split the engine.....??

guzzijake
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Re: central bevel gear extractor

Post by guzzijake » Sat Jan 19, 2019 2:11 pm

Well, I'm quite sure that the central bevel needs to come down by quite a ways, it can't be good for the engine running on the tips of the teeth like this? So, I'm following Steven Eke's book and I think I need to get a hold of a special tool to pull it out from the top and put in some shims/washers?
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P1011093.jpg
P1011093.jpg

wdietz186
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Re: central bevel gear extractor

Post by wdietz186 » Sat Jan 19, 2019 3:21 pm

Is there play in the dist. drive gear or the tower shaft gears? That may be the way it left the factory. Dropping the gear down [if it can be done] may bind them up and raising the tower gears would introduce too much play. Is it quiet when running?
To get the center bevel out it looks like the crank need to be out of the way so it can drop down far enough. The factory must have set up the drive gears before the crank was installed. I remember reading the engine was very labor expensive to produce, probably explains the exemplary paint and chrome quality along with the superior electrical system.

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Craig in France
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Re: central bevel gear extractor

Post by Craig in France » Sun Jan 20, 2019 2:55 am

guzzijake wrote:
Sat Jan 19, 2019 4:44 am
hey craig, yes that the one, the central conical bevel gear. I thought I needed that extractor to pull it out from inside the distributor hole and put in some shims.
Ok, got you Jake. One for sale here. It's expensive, but you might be able to sell it on again (on the 860, you can just tap out the bush from below. But I guess - I don't know - that that doesn't work on the 750?)

https://www.ebay.co.uk/itm/Ducati-Bevel ... 0011.m1850
guzzijake wrote:
Sat Jan 19, 2019 4:44 am
How does one go about getting a proper mesh between the three bevel gears? Mine is a good millimeter and a half out ... I could probably use washers instead of shims...
As you say, by adjusting the installed heights. And I can't deny that you do seem to have a bit of a mis-match there! How important it is in practice, I don't have the experience to say.* Problem is, as you change the ride heights below, you risk modifying the interplay of the rest of the bevel drive components.

As Bill says: this complexity made these engines time-consuming = expensive to build, and is why the system was changed for the 860.

* Jake: I'm going to pm you with the contact details of someone who knows these engines and should be able to advise you.

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Craig in France
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Re: central bevel gear extractor

Post by Craig in France » Sun Jan 20, 2019 3:33 am

guzzijake wrote:
Sat Jan 19, 2019 11:49 am
please dont tell me i need to split the engine.....??
You don't :-D .

With regard to Steve Eke's book: The illustrations there are taken from the factory manual (less color :) ), with the text somewhat re-written. However, certain illustrations are missed out :shock: . So, as a first step, you might want to download a copy of the factory manual from here:
http://www.ducatimeccanica.com/roundcase_rebuild/

However ...
I notice that this version only has the English text; and experience has taught me that the original translations from Italian into English are not always correct - and sometimes not even complete! Which I why I always refer to the original Italian.

I can't find a copy of the Italian manual at the mo' - but they are out there!

guzzijake
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Re: central bevel gear extractor

Post by guzzijake » Tue Jan 22, 2019 2:21 am

ok thanks Craig, it would be really helpful to talk to someone who has actually some experience of these things. The engine has clearly been apart before, quite possibly more than once, and to hazard a guess, whoever did it made a pigs ear of it. It cannot have left the factory with that kind of mesh between the lower bevel gears. I most definately do not want to split the engine to fix it, I don't mind buying that puller and playing around with washers to get it right but just want some guidance on how to accomplish it. Thanks for the pointing me in the direction of that ebay seller. Ill check my PM's now.

guzzijake
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Re: central bevel gear extractor

Post by guzzijake » Tue Jan 22, 2019 2:27 am

wdietz186 wrote:
Sat Jan 19, 2019 3:21 pm
Is there play in the dist. drive gear or the tower shaft gears? That may be the way it left the factory. Dropping the gear down [if it can be done] may bind them up and raising the tower gears would introduce too much play. Is it quiet when running?
To get the center bevel out it looks like the crank need to be out of the way so it can drop down far enough. The factory must have set up the drive gears before the crank was installed. I remember reading the engine was very labor expensive to produce, probably explains the exemplary paint and chrome quality along with the superior electrical system.
Cant see how dropping it down would bind them up, they are running on the edge of the teeth now, have a look at the picture. I wouldn't have a clue how it runs, there was no compression on the upright cylinder (valves were closed up and not sealing), it was covered in bird dog doodie and in pieces. I didn't want to attempt starting it without giving it a moderate once over. I've done the top ends, got the compression up, replaced some rocker arms, re-set the mesh of the top bevels (they were miles out) and thought that, given how far the top bevels were out, I ought to have a look under the stator cover.

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Craig in France
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Re: central bevel gear extractor

Post by Craig in France » Tue Jan 22, 2019 3:01 am

guzzijake wrote:
Tue Jan 22, 2019 2:21 am
The engine has clearly been apart before, quite possibly more than once, and to hazard a guess, whoever did it made a pigs ear of it.
Yep, happens, especially with mechanics who are more used to working on Japanese machinery. Mind you ...

Many years ago,I left my 860 at a so-called Ducati specialist for a cam to be replaced. When I went to pick the bike up, the rocker shims were lieing in the tool tray ... :shock:

Learnt a lesson there - the first of many, unfortunately :roll:

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