cheers hatman and paul, how do you know which one to buy or does it not matter.
i havent heard of tapered and parralell threads (is one for disco and other defender)?
According to Microcat, both the Defender and the Discovery could have either type fitted.
You should replace like-for-like, which means that you'll have to look to see if you can see a part number on your current one, or remove it and examine the threads.
Parallel threads are the same diameter along their length and usually have a sealing washer on the mating face.
Tapered threads taper along their length, getting slightly larger along their length (towards the switch body), so that as you screw it into the matching tapered thread in the block, it tightens-up and seals the hole oil-tight.
Looking at the Discovery II Workshop Manual and Microcat, there's no mention of a sealing washer
Have a look at your existing switch to see if you can see a part number, it doesn't have to be one of the ones I posted above, it could be the OE Manufacturers part number, which I might be able to cross-reference.
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