NA/NB torsen LSD - identification guides

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greenMachine
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NA/NB torsen LSD - identification guides

Postby greenMachine » Mon Oct 26, 2020 9:27 pm

93_Clubman responded to a question I asked about how to distinguish between the T1 and T2 torsens in NAs and NBs. I am reposting those replies in a dedicated thread, hopefully to make the information more readily findable for anyone asking the same question in the future.

93_Clubman wrote:GM, as you probably know removing the oil filler plug & looking inside allows you to identify whether Torsen or open diff.
Solo Miata reckons you have to disassemble diff to identify whether Torsen Type I or Torsen Type II: http://fixjunk.com/solomiata/solomiata/MiataVLSD.html
'(Q) How do I tell a Type I from a Type II Torsen?
(A) You have to disassemble the housing to view the actual Torsen LSD unit. The easy way to tell is the worm gears on the Type I are perpendicular to the axle shaft (crossed axis helical) and the worm gears on the Type II are parallel (parallel axis helical). The picture above is a Type I. '
But I reckon due to the manufacturing differences between the Type I & Type II you could identify which type by removing the oil filler plug & looking inside, but could be wrong:
'The 1994 and 1995 Miata have a Type I Torsen, which is the traditional worm gear unit. '
'The 1996 and 1997 Torsen is a Type II. This unit has a different design with the worm gears being replaced by three sets of drive gears that are mounted with their axes parallel to the ring gear axis. ':
https://www.miata.net/garage/diffguide/index.html
Some other resources:
https://www.miata.net/garage/vlsd.html
https://www.beavismotorsport.com/guides ... miata-mx5/


and ...

93_Clubman wrote:Pics of T1 & T2 in following should allow identification of which type via oil filler plug hole: https://forum.miata.net/vb/showthread.php?t=449338


Thanks again Clubman!! :beer:

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Re: NA/NB torsen LSD - identification guides

Postby greenMachine » Tue Oct 27, 2020 12:05 pm

Just noticed the Beavis link above has been truncated in my repost. It takes you to the website, but here is the link to the specific page:

https://www.beavismotorsport.com/guides-tech/differential-guide-for-miata-mx5/

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Re: NA/NB torsen LSD - identification guides

Postby greenMachine » Fri Aug 13, 2021 5:45 pm

Does anyone know if the colour of the filler plug means anything?

I have discovered a busted diff in my shed, one arm broken. It is a 7in diff, and open not LSD. The filler plug/bolt head is coloured greeny-yellow, and I am wondering if that might point to a particular final drive ratio.

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Re: NA/NB torsen LSD - identification guides

Postby 93_Clubman » Sat Aug 14, 2021 12:19 am

According to the various diff guides there aren't external indicators of diff type & think this extends to FDR.

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Re: NA/NB torsen LSD - identification guides

Postby greenMachine » Sat Aug 14, 2021 8:07 am

Thanks Clubman, I was hoping to avoid getting my hands dirty :lol: 8) , seems like counting the teeth is the way ahead.

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