Hi, I need to remove the cover over the timing chain on a K75 engine. There is a seal on the cover that seals the hall effect sensor shaft. Will it be necessary for me to unconditionally replace that seal when replacing the cover? Or is it reusable as is?

Seals are reuseable but it probably is something like 25 years old. Unless you know for sure it is only a few years old I replace them as a matter of course. With the heat there or anywhere on an engine I would be using a viton seal as they cope with the heat much better than a norman Nitrile seal.

Thanks Rick. That particular seal is similar to the rear main seal but it is shaped in a way that necessitates a special BMW installation tool to ensure the seal wiper is correctly positioned. I'd replace the seal if it is deteriorated but don't relish the thought of trying to fit a new one. I hope the old will be easier to refit (maybe I'm mistaken though).

there have been a few threads about that particular seal and installation rob

some clever folks found a pill bottle that works well for the sealing lip, to hold it in place whilst the housing- seal is reinstalled

I did that seal on two Ks before I found out about the special trick but I just make sure the lip goes on correctly when installing and have not had any trouble. Of course now that I have opened my big fat mouth I will probably find a big pool of oil right there under the hall sensors.

This was the small win for me. Works well.
Hope you don't struggle with all the technical lingo.



'So I was stuck on how to get the timing case cover and the seal over the shiney spinny thing at the front without the edges folding over on the seal.
This is where the Fanta came in.
I put this on the inside of the seal with the cap toward the front of the bike, pushed the timing cover back into place and hey presto. The fanta top came shooting out the front and the seal was perfectly in place. Score 1 for me.


Not sure if I should post this in the 'how to' section? I may lack a few photos, but this is at least as good as Alby's recent sprag clutch how to'.