Layshaft bush in the driving side crankcase

Hello John!

I would go for a new one while you are this far down in the gearbox.

No 041289 in the NOC Lightweight catalouge

if you have the early type gearbox

Hello John,

I would most definitely agree with Ulrich. This bush spinning and blocking off it's oil supply is the most common form of failure in this type of gearbox. You seem to have caught the problem in time so it makes good sense to replace the bush and loctite it in place. In fact it is usually recommended that this bush is pegged in place but I don't know if this is feasible for most home mechanics.

The normal cause of this failure is running the gear box low on oil and the usual cause of low oil is oil leaks which are very common. So while you have things stripped replace all the O rings and gaskets as well.

Patrick

Yes it is, usually it's not much more to buy a bigger bottle so you have a lifetimes worth!

Previously john_dunn1 wrote:

Thanks Guys

Will order new bush and loctite it in place. loctite bush retainer seems very expensive.

Thanks

John.

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As has already been mentioned, the Lightweight engines (all Jubilee & Navigator prior to 106837) have this potential problem. Electra and later Jubilee & Navigator engines have this bush pegged to avaid rotation.

If left too long the result can be fatal, as brass spinning in aluminium is not good. Loctite Bearing Fit & Retainer - there are several products out there..Loctite 641 is what I used previously - but it seems too weak. Is there a better Product to use? Loctite 660? Others? The choice seems bewildering.

Picture of engine damaged by this bush rotating without the owners knowledge attached. This could happen to you. Take note of my breather pipe suggestion too. Early engines had a breather pipe too close to the chain.

Loctite that bush in place! (& pin it if you can!)

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broken-cases-jpg

Just looked here & answered my own question:

http://www.loctite.co.uk/retaining-9171.htm

Combining High Strength & High temperature - use Loctite 638

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Hello I still have my Jubilee project on the go, it's in its 6th year now, so not being rushed. I replaced the bush on my own and drilled and pinned it, what are the benefits of moving the breather pipe.

Cheers Kelvin.

Previously kelvin_potter wrote:

Hello I still have my Jubilee project on the go, it's in its 6th year now, so not being rushed. I replaced the bush on my own and drilled and pinned it, what are the benefits of moving the breather pipe.

Cheers Kelvin.

I have this problem. Is there a workshop manual or any procedure for doing this fix? What is involved? Where do you get the parts, are they stocked by the NOC? James.