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Hi All,

Want to swap out my gearbox and diff oil. Can't find a thread which addresses this.

I have been pulling my hair out trying to pin down what to use, but it seem like all the mech's that know use different brands and viscosity.

Mazda tell me after a while on hold (No it's an NB not and NC, and yes I'm sure its 2004, and yes its a factory turbo!) that gearbox is GL-4 75W/90 and diff is GL-5 90. (Has anyone else encountered "computer says" no when you call Mazda about your SE?)

MX5 Mania use Redline MT-90 for gearbox, and for diff Redline GL-5 75/90.

Michael at Deckspeed swears by Castrol SYNTRANS or SYNTRAX stuff. He said he's used everything else and on track Castrol is the only stuff that hasn't boiled and blown gearboxes.

Castrol website says for (turbo 2002-03 no 04/05?) gearbox use CASTROL MANUAL VMX-M 75W-85 or CASTROL UNIVERSAL 80W-90, or CASTROL SYNTRAX UNIVERSAL PLUS 75W-90, and for diff CASTROL AXLE EPX 80W-90.

I'm leaning towards CASTROL SYNTRAX UNIVERSAL PLUS 75W-90 for both box and diff...it looks like it'll do the job in both ( http://www.castrol.com/en_au/australia/ ... 5w-90.html ).

Alternatively CASTROL AXLE LIMITED SLIP 90 which is mineral not synthetic for the diff only...it is exactly what Mazda recommend (http://www.castrol.com/en_au/australia/ ... ip-90.html )

Was wondering if anyone could shed some light? Particularly where to buy the stuff - no-one seems to stock small quantities in Syd.

Cheers,

Jk

Stick redline mt90 in them both. It's fully synthetic GL4. I run it in both my Standard NB and supercharged NA. There are other options which others will recommend that will also serve you just as well.

Do more searching, there's heaps of threads on oils for NB's.
Castrol or Redline or any other major brand will be ok.

However, the Limited Slip 90 could be for clutch type LSD's only. The owners manuals for cars with torque biasing diffs/torsens usually say 'don't use LSD oil'.

Cheers

Thanks Red_Bullet and RS2000 but I own an an SE.

As I understand it the gearbox (same as Altezza RS200 and other hi-po Jap. cars) and diff (torsen LSD) are not the same as the standard NB's so I'm reluctant to follow the threads for same.

Cheers,

Jk

Is the SE diff a hypoid? If so Redline MT90 isn't suitable.

JustinK wrote:Thanks Red_Bullet and RS2000 but I own an an SE.

As I understand it the gearbox (same as Altezza RS200 and other hi-po Jap. cars) and diff (torsen LSD) are not the same as the standard NB's so I'm reluctant to follow the threads for same.

I have an SE too and the LSD diff is actually a 'cone' or 'Auburn' type, same as used in the RX8, NC & ND.

For the gearbox, Redline MT90 is a favourite and I believe it can also be used in the diff.

I attended the Nulon Oils tech night run by the MX5 Club of NSW recently and they said that any GL4 or GL5 synthetic oil would be fine, it is only when you get to the NC gearbox that you need a GL4 specifically.

That being said, DO NOT USE VALVOLINE!!
This was put in mine by the workshop that did my 100K service and it doesn't play nice with the Assin 6-speed. I'll be dropping it out when I do my next service.

Yippee!! Another oil thread ...

I had a bottle of Royal Purple Max Gear left over from my previous NB, so I used that in my SE's diff. In the gearbox, I used Redline MT-90. Felt better than whatever was in there from the previous owner.

Thanks Nevyn72 and KevGoat.


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Castrol VMX-M

I use it in both box and diff.



Mine's got a Torsen T2, which really arent fussy what oil they use. The guy who built my diff said people use everything from Regular gearbox oil to Auto trans fluid without issue.
He said that he personally doesn't recommend ATF since it's very thin and won't be able to protect as well as gear oil.


Look up what LSD the SE uses though, from memory it's not a normal Torsen, but a similar design.
I'm 99% sure it's not a clutch-pack though.

Castrol VMX-M

Stick that in then, these people know more than me. I might use it next time myself, I'm sure it's just fine. But I'm not going to take the Redline MT90 out to put it in.

There are plenty oils which will serve you well. There are way better things to do with MX5's than worry about what extreme quality oil is best.

Stick decent oil in and drive it.

Cheers guys.


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Redline! Transformed my 6spd. Make sure to get the upper and lower shift boots and nylon shifter bush as well.

Thanks Ems


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