450 SCR engine rebuild

[Wolf]

...it worked without larger bloodshed. I inserted a 1 mm drill and with some heat it came out - I think it was worth it, the hole in the lever is more an oval and the pin is pretty worn. Thanks a lot for the good advice!
Cheers Wolf

[Duccout]

Well done!

[Wolf]

...maybe better than new...

[Wolf]

...but I've found a new issue: the lower bevel drive shows axial play. Strangly I noticed this only after heating the casing in order to remove the gear box bearings. Prior to the heating there was no noticable play.

Is there a good "how to" avaiable?

Many thanks!

Wolf

[Duccout]

Hi Wolf,

Do you mean play between the steel housing and the crankcase, or play in the bevel shaft and the bearings? Both of these are dealt with by shimming, the shaft needs shims placing under the circlip to take out play, or the steel housing has shims placed under the top clamp to hold it securely into the crankcase housing. I apologise if I have mis-understood what you are saying!

Cheers,

Colin

[Jordan]

Strictly speaking, as the gear pairs are helical bevels they should be matched to each other.
Shims at the crankshaft and the short vertical shaft achieve this.
You can spend much time researching, trial fitting, checking with engineer's blue.
Or you can just take out the play with random shims and hope for the best.
But that shortcut could lead to noisy operation and rapid wear.

If the gears are matched, they might have grinding marks on the edges of both. It was standard factory procedure, evidently.
The grinding serves two purposes.
The first is to identify the gears as matched pairs, as the grinding leaves a unique "finger print" visible at the interface.
Secondly, the ground surfaces must be at the same level after shimming and installation.

Such is my understanding.

[Wolf]

Hi Colin,

it is axial play between the bevel shaft and the bearings. I will look deeper into it.

Hi Jordan,

I think I'm more the "engineer's blue"-type. I think I've seen the grinding marks but did not realized their meaning - thank you for pointing me in this direction - this might come handy!

Cheers

Wolf

[Duccout]

Hi Wolf,

This is in case you don't know - if you do, discard what I say.

The bearings in the lower bevel housing are angular thrust bearings and they have to be drawn together by fitting the shims on top of them, and then the circlip goes in place to keep them tightly together, which removes any play. The circlip usually wears over time and this loosens the assembly, so a new circlip is a good idea and it needs to be pushed into the groove over thick enough shims to take all of the play out of the shaft.

Cheers,

Colin

[Ventodue]

<snip> Is there a good "how to" avaiable?

This may be useful, Wolf - from page 13 onwards.

https://jumpshare.com/s/GMW9TtivoNgpohGfAThU

[Wolf]

..thanks a lot for the valuable input, the "how to" instruction will be needed as a matter of fact.

I've looked for the grind marks the bevel gears, they are existing.

greetings

Wolf