# How does a helical LSD work?



## Zombie Elvis (Jun 21, 2004)

I've searched the site for an answer and found nothing - I swear 

I want to understand how these diffs work. When I was buying my S15 the sales rep showed me a small wire-frame diagram but it showed fark-all and didn't have any explanation.

All I've been able to find out so far was that there is some sort of teeth gear that bites into the shell of the diff, and it has a very progressive and smooth locking action that is a class above other types of sticky diff.

A few links or even a brilliant explanation would be most welcome.

Bonus questions:

the Skyline V-specs (and maybe others) have variable diffs which I think are also helical - how is the variable lockup integrated into the diff?

Is the variable capability in all delivered helicals (eg in my s15) : if so, what sensors are used to trigger the adjustments? I've noticed that my diff has a wire coming out of it, but I've heard that this is for the speed sensor.
-- 
I'd rather be sideways.


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## sky-240 (Jun 28, 2004)

I read a usefull bit of information at www.sportcompactcarweb.com/projectcars/0309scc_projectsilvia/. There's an article in there about getting a 240 sx into the 12 sec bracket. The majority of the article was about three differant types of posi diff, how they work, and what they're good for. I hope it will help you.


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## Slayer2003 (Jun 4, 2003)

this site can answer pretty much any question about how stuff works, heh.

http://auto.howstuffworks.com/differential.htm


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## Zombie Elvis (Jun 21, 2004)

sky-240 said:


> I read a usefull bit of information at www.sportcompactcarweb.com/projectcars/0309scc_projectsilvia/. There's an article in there about getting a 240 sx into the 12 sec bracket. The majority of the article was about three differant types of posi diff, how they work, and what they're good for. I hope it will help you.


Cool - once i put IN the spelling mistake in the link .... _projectslivia instead of _projectsilvia, I can see that page, and it explains helical about as well as can be done without seeing an actual diagram. I think I'm starting to get the hang of it.

thanks


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## Zombie Elvis (Jun 21, 2004)

Slayer2003 said:


> this site can answer pretty much any question about how stuff works, heh.
> 
> http://auto.howstuffworks.com/differential.htm


Cool - good explanations of the other standard diff types. Nice diagrams.


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