450 SCR engine rebuild

[Wolf]

...the circlip does not look that good, but I think it is not the culprit - the loss of thickness is less than 0.03 mm - the axial play still exists with the worn circlip replaced. I will look deeper into it...

[Wolf]

...some progress here: I've bought and modified a 2nd gear pinion since the old one showed some decay.

[Wolf]

...and something annoying: the new main shaft from Ducati Vintage shows some a deviant geometry compared to the old part. The 4th gear pinion won't spin freely.

Regards

Wolf

[Duccout]

Hi Wolf,

This is the problem with remade parts, the quality control is poor. Can you lap the 4th gear onto the shaft with metal polish? And could you take up the extra with of the circuit groove with a shim?


Cheers,

Colin

[Jordan]

...some progress here: I've bought and modified a 2nd gear pinion since the old one showed some decay.

2nd gear is the weakest part of the 5 speed gearbox evidently.
That's an interesting idea - by removing the web between the dog and the gear, it's less likely the gear will develop a crack that starts at the dog.

[Wolf]

Hi Jordan,

I also thought that this is an impelling idea. Not my idea - you can buy the already modified 2nd gear here:
http://www.desmo.shop ; search for 060316020

I've bought the gear wheel at Ducati Vintage and let it modified by a colleague who is handy with a grinding machine.

Hi Colin,

the problem is with the axial position of the grooves for the spring rings. The remedy will be grinding down the 4th gear pinion to the adapted length. Diameter of the main shaft appears to be OK.

Cheers

Wolf

[Wolf]

...I need some help/insight: In case I've to add/remove shims from under the lower bevel gear - do I need to extract the whole bearing cartridge? Is this the way to shim the lower bevel gear?

Many thanks!

Wolf

[graeme]

Hello Wolf,
I have just done this on a 450,,,,,
Yes, the crank has to be removed and the lower bevel bearing carrier has to be lifted up a bit.
If the 2 bottom bearings are the self aligning type (mine are) you can lower the lower bevel until the oldham half cut is below the upper bearing, then pull the bevel outwards so the bevel clears the crank case casting. Slide it out, add or subtract shims, then re install the shaft into the 2 bearings and press the carrier back down towards the crank shaft.
Very time consuming.

Regards
Graeme

[graeme]

ps,,,

If you have already finished the crankcase internals and you don't want to remove the crank, you may be able to remove the lower bevel by lifting the bearing carriage higher. Never tried but it should work the same.

Graeme

[Wolf]

Hi Graeme,

thanks a lot for your encouragement!

I assume I was able to shim the lower bevel drive without touching the vertical shimming. This make sense since the only new part was the crank shaft, the bevel wheels stayed the same. For some reason it was necessary to adjust the preload for the bevel shaft.

Cheers

Wolf