Just curious...

[CRDMS1]

...why nobody is using the Redline 75W90 Gear Oil in the Mazdaspeed tranny. From their website...

75W90 Gear Oil - the preferred product in nearly all car and light truck differentials, both conventional and limited-slip. 75W90 is preferred for most racing applications. It contains friction modifier which is recommended for limited-slip units. 75W90 Gear Oil can be used in many transmissions and transaxles; however, other Red Line lubricants have better frictional properties for rapid synchronization. Exceeds API GL-5.

Interesting that it specifically mentions a 'friction modifier' for LSD applications. I've seen threads recommending MT-90, MTL, and Shockproof but none of them mention anything about LSD.

Anyway, I plan to switch tonight and would love to hear your comments on this issue before I have to go pick up my fluids. I also will call Redline when they open...

Peace...(hippy)

 

[kpracer94]

haven't tried redline but amsoil makes 75w90 that is designed
to work with LSD,s. amsoil also makes an additive called SlipLock
in a 4 oz. bottle that you can add to any other fluid.

 

[Logan]

I've just heard too many horror stories about redline in subaru trannies.

 

[changedman]

what could happen with redline fluids? is there something im missing?

 

[CRDMS1]

Redline is a well respected product in the synthetic/racing community and usually shows well in independent testing. I'm not sure about the Subaru issues, but several members of this site use their products with no reported problems that I can recall.

Back on topic!

Peace...(hippy)

 

[CRDMS1]

Never mind. I spoke to a guy at Redline who kindly explained that the 75W90 gear oil with friction modifier is for the clutch-type LSD only (chatter). For our car, he highly recommended the MT-90 for daily driving with the occasional autocross mixed in. Picked mine up at lunch...$6.95 per quart + tax (case purchase).

Peace...(hippy)

 

[Dexter]

cool, i gotta do this sometime soon

 

[Fakhelek]

Never mind. I spoke to a guy at Redline who kindly explained that the 75W90 gear oil with friction modifier is for the clutch-type LSD only (chatter). For our car, he highly recommended the MT-90 for daily driving with the occasional autocross mixed in. Picked mine up at lunch...$6.95 per quart + tax (case purchase).

Peace...(hippy)

What is the difference between the MT-90 and the Shockproof oils?

 

[CRDMS1]

What is the difference between the MT-90 and the Shockproof oils?

Without getting into all the technical stuff which I barely understand anyway, Shockproof is intended for long duration racing-type applications where the transmission sees much higher temperatures than normal. For normal spirited driving and occasional autocross or drag racing, I see no real added benefit over MT-90.

You can read all about Redline products on their website at:

Redline Products

Peace...(hippy)

 

[Fakhelek]

Thanks for the info. I'll check it out.

P.S. You should listen to The Cars in your black MSP. I do and it's great.