NB diff failure

[Big G]

Guys there is a thread running on the UK forum about diff failures on the NB. At an oil change members have found bits of metal in the oil [large bits].
Any one on here found this problem.
Here's a link to the forum
http://www.mx5oc.co.uk/forum/forums/t/19726.aspx

[greenMachine]

Guys there is a thread running on the UK forum about diff failures ...

http://www.mx5oc.co.uk/forum/forums/t/19726.aspx

A closer look at those threads indicates they are clutch pack LSDs. As far as I know, the NB LSDs here are all torsens (except for the smaller NA-only viscous LSDs), and those threads specificly exclude torsens from this problem.

Might be an issue for NCs, don't know what they use.

[manga_blue]

I'm just trying to work it out too. The LSD diff centres illustrated in my US parts books for NB8B and NB8A don't look anything like the NA8 Torsens. Did we get Torsens and US/UK get clutch types?

[greenMachine]

Hmm, good news, bad news.

Bad first. They do seem to be 'torque sensing', by description though not name, though there are some contradictory posts regarding nomenclature. These LSDs seem to be on 2003 and later NBs, in US and UK. However, one post claims Mazda changed suppliers resulting in the supply of these troublesome LSDs - this would imply that ALL post 2003 NBs with LSDs are prone to this failure, on the assumption that Mazda would only source one type of LSD.

Good news is that no one here seems to have had a problem, possibly because all the LSDs sold here were TORSEN brand torque sensing diffs (if this was in fact the case - anyone know? - Caff, are you reading this?). The diffs reporting problems look very different to what we know as torsens, but who knows what has come in by container from Japan ...

Or have there been problems, that just have not surfaced in places like this? Caff, where are you when we need you?

If you have had a second hand LSD put in that you didn't see before it was installed, or you installed a second hand full LSD diff in its housing, it might be worth doing an oil change, just to see what is attached to the drain plug ... ... or hopefully

[flycasta]

They dont look like the standard tabs off a plate LSD. because of the way they are square edge at the lowest point of the photo and rounded at the top would indicate they have been snapped off from the rounded area. That would mean that the square edge is like an external lug and none of the plate LSD's I have seen from Mazda have those square edge tabs they are all rounded like this.




Not a good photo sorry but you can get the general idea of roundness. The Cusco has squared edges but would not have been fitted as original equipment. None of the Type 2 torsen I have stripped down have anything like that inside either. It might be a part of a viscous LSD or a type 1 torsen as they use thrust plates inside them as well but I have never pulled one apart so cant say what is in them. The NC's have a spring type preloaded side gear LSD in them and they aren't very good anyway. I am pretty sure the whole world got the same LSD's as they all originate from Japan and they generally dont make different LSD's for different parts of the world.

This is what the NC's have. The Japanese seem to think they are better than the Torsens but I beg to differ.

[Caffeine]

Only the clubman, 10AE and SE's came with LSD's in Australia, all TORSEN types. (excluding the NC, no idea what they have)

[NitroDann]

NC has no lsd. And those arent torsen inner bits.

Dann