Leaky Alternator cover... torque settings?

[utopia]

If I read it correctly, the workshop manual for my later model (2001) 750 says 10Nm for the M6 casing screws.
I can't find anything specifically for the alternator cover .. only a general spec for "casing jointing screws".

If you're cleaning up and re-gasketing (be it threebond or otherwise) its important to tighten evenly.
My method is usually to refit the cover in question and fit all the screws, winding them in until they are still slack, but are just a tad short of snugging down.
Then I like to push the casing fully home with my hand and hold it moderately firmly while snugging the screws down using minimal torque (eg using a gentle hand and an allen key fitted "the wrong way round").
Only then will I apply some proper torque, and usually in stages, beginning with the same "wrong way round" allen key and a firmer hand and then the full torque.
In the absence of a torque wrench, 10Nm (or about 7.5 ft.lb) equates to something like a moderately firm hand on a std allen key (used "the right way round").
And importantly, all of this tightening should be done in a zig-zag sequence across the casing from one side to the other, to avoid tilting the cover. The first screw to tighten would be the one which looks most central to the bulk of the case, finishing with the outermost one.

If you use threebond, don't apply too much of it as you don't want too much of it to squidge to the innards of the case, from where it could later detach and get where it shouldn't.
Also beware of applying it where it could squidge into any oil holes or compromise any dowels.

[Flip]

Originally Posted by utopia

If you use threebond, don't apply too much of it as you don't want too much of it to squidge to the innards of the case, from where it could later detach and get where it shouldn't.
Also beware of applying it where it could squidge into any oil holes or compromise any dowels.

I'll completely second Utopia's advice there.

You have to remember the prime reason for using a sealant like Threebond is money saving on a factory assembly line- basically they no longer have to have a specific gasket for every application on each and every model the company produces.

In addition, they will have a very precise process in place for the application of said sealant and if, like the company I work for, it will be pneumatic with a set speed for the nozzle to move so that correct amount is dispensed.

For an idea, I did a little experiment at work today using a hand applied 3mm bead (as recommended for Threebond in the eBay listing in alan S4's post) of a similar sealant between two pieces of Perspex compressed under finger pressure.

You can see the kind of spread and the potential of the silicone getting into places it shouldn't.







Call me old fashioned but I would rather make a gasket from good ol' Flexoid than risk a blocked oil-way.

https://www.ebay.co.uk/itm/Genuine-F...941b2a1e3059d4