Thanks Voicey. That is a fine mess.This is what it will look like when you manage to get a stuck one out - you will destroy it in the process and then to top it off, it'll snap into two pieces leaving half in the gearbox. Fortunately the bit left behind is easily retrieved.
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And this is what you want to be on the lookout for...
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The "improvement" to the filter is to simply move the o-ring closer to the outside of the gearbox (the filter shown above is the old design). This prevents crud getting in and corrosion occurring. The part number is unchanged and I'm yet to get an old style filter so I would say the stock has been run out by now.
I guess this is often one of the things that we can trust a decent indy to do but often don't get done by main dealers even when the charge for it. Pollen filter another.