Shimming Bevel Gears

[JasonB]

Hello all,
I was wondering if anyone had any info on shimming bevels gears... my motor was a basket case when I got it and since having trouble with the gearbox I am starting a engine rebuild and would like more info on shimming gears.. i think it might be a degree in the art of shim way (-;


Regards
JasonB

[DewCatTea-Bob]

" I was wondering if anyone had any info on shimming bevels gears..."

____ I'm fairly sure this topic has already been touched-on within another thread...
Please try a search here, and if you can't find any related-info, I'm sure we'll still help you with any specific question.


Hopeful-Cheers,
-Bob

[Bevel bob]

A good selection of shims in hand, unload the gears (remove rockers) ,aim for the smallest amount of play , a mikecrometer to measure the shims. get the ground areas to meet ,a pencil and notebook,spare new circlips ,consider how a new gasket will change everything, be prepared to do the job over and over till its right,Don't even start if the bevel bearings are not right,If the crank is not shimmed in the cases right you are wasting your time, make sure that the bottom bevel bearings (and spacer) are held down in the steel bushing by the alloy housing and its big shim which may all be compromised by a thicker new gasket,think about the nip on gaskets, be prepared for some deep thinking!!.When your sure its perfect check it again, work in comfort in good light and with patience. Consider that the everlasting bevels on Hailwoods IOM Ducati self destructed on the finishing line ,were they set up right do you think?,even the experts make mistakes.

[JasonB]

Thanks for the reply guys, I did search for bevel shimming on the site and didnt find what I was looking for, I was suggested to use a product call bearing blue, where you coat the surface on each gear to see where they are making contact, I am assuming you have to take into account heat as well ??

Regards
JasonB
This site is a wealth of knowledge ....

[Rick]

JasonB,
The process you've heard about is common in setting up worm gear reducers and auto ring/pinion assemblies- I've done it for industrial power transmission gearboxes. This pdf file describes it:
www2.dana.com/pdf/AXSM-8663.PDF
But, I've never heard of a Ducati mechanic going through this 'contact patch' ritual- it's usually done by feel- loose enough not to bind and whine, but not 'too' loose- I think there are Ducati service manuals in the tech section of this site that go through the Ducati method.
Okay, I looked it up:
http://www.motoscrubs.com/Ducati_Manual ... d-shop.pdf
The suggestion to adjust the gears with no load is good advice, it's hard to tell if they're binding with external pressure on them, that is , until they turn blue and shear off.
Rick

[Pete]

There is an article in one of the old DIOC newsletters about shimming bevel gears

http://www.bevelheaven.com/dioc/dioc40.pdf

Pete

[Bevel bob]

Blueing gears is for when unmatched odd gears are used and helps to get the tooth loadings in the right place.