If you have'nt already, make sure you clean the breather filter
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I didn't like that breather cap too much so I got a length of hose, a jubilee clip.
The bit of foam from the cap is now in the end of the hose up near the air box.
Is that to keep it clear of Mud and Stuff when you're Off-Roading?
I don't go off the Tarmac a great deal so it's not such an Issue for me.
If you have'nt already, make sure you clean the breather filter
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33 11 8 560 809 FILTER
parts fiche
Make sure oil level is correct and also correct grade - GL5 - ie non-foaming.
So, best bet would probably be to change the oil - then you know the level is correct AND it the correct grade
Also, make sure the breather still contains the foam filter/restrictor - it seem to break up with age and disappear! breather cap just pops of with a couple of screwdrivers.
Cheers....................Grizzly![]()

After >15 years the foam will decayed into powder and fallen into the oil. Drain and refill with fresh hypoid oil of the correct grade and fit a new bit of foam.
I think it has to sqeeze down into the steel pipe that the black breather cap clips into. It's a few years since I replaced one - but I think that was the only "sensible" place it fits into???
I have a spare new one in the garage and have attached a photo - it's a very soft open-cell foam 14mm diameter x 16mm long.
The bevel box only has to breath very slightly and slowly as it warms up and cools down. I suppose the idea of the foam filter is it helps stop the escape of oil and the ingress of water and dust etc???
Cheers.................Grizzly

Filter only costs £1 from your local BMW dealer...........................Grizzly
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