For those that have LSD noise after switching to MT90

[hectik1]

It tore up the Ford Contour's trans (one of my former cars). It was put into my Evo when the clutch was done...then I had 3rd and 5th gear go which I traded for my MS3. It will never touch my Speed.

Your reasons? I got an easily discernible improvement in shift quality after switching to MT90, especially 2-3. There may be even better oils out there that I have not tried, but I would never go back to the factory fill after living with MT90 and I am unlikely to switch because I am quite happy with it.

Just to recap, A cone clutch lsd that does not moan when cold at full lock and low speed is unlikely to provide limited slip functionality at WOT. Friction modifiers are meant for plate type lsds in stand-alone differentials and interfere with the function of transmission synchronizers. The lubrication is shared by the transmission and diff in the MS3 and that is why Mazda chose a cone-clutch lsd. A Torsen/Quaife type lsd would have been a better, but much more expensive option.
-enganear

 

[enganear]

It tore up the Ford Contour's trans (one of my former cars). It was put into my Evo when the clutch was done...then I had 3rd and 5th gear go which I traded for my MS3. It will never touch my Speed.

Hmmm, OK. I question the responsibility for your transmission issues. It sounds like you are just hard on transmissions. in 40 years of autocrossing and aggressive street driving in a multitude of cars, I have never damaged a gearbox.
-enganear

 

[fastdreams]

Just to recap, A cone clutch lsd that does not moan when cold at full lock and low speed is unlikely to provide limited slip functionality at WOT. Friction modifiers are meant for plate type lsds in stand-alone differentials and interfere with the function of transmission synchronizers. The lubrication is shared by the transmission and diff in the MS3 and that is why Mazda chose a cone-clutch lsd. A Torsen/Quaife type lsd would have been a better, but much more expensive option.
-enganear

Thanks for the info.

However, my car did not moan one bit with the stock fill. By your statement above that means the stock fluid does not allow the lsd to function correctly?

I'm not sure I buy that.

On the other hand, I don't care one bit about the moaning in my lsd with the motul, thanks to this thread. I thought it was because I track hard and put the lsd to hard use. But so far I have perceived no performance degradation, and shifting is somewhat improved, though still not great.

 

[RichB]

my car did not moan one bit with the stock fill. By your statement above that means the stock fluid does not allow the lsd to function correctly?

You are correct. The factory fill did prohibit the LSD from functioning properly. This is why shifting with the factory fill sucked as well. I'm not sure what the factory fill is, but from what I felt it's like it has way too much friction modifier in it. Mazda chose to make the LSD quiet which sacrificed performance.

 

[ericrapp]

Is not that always the way, the intake the exhaust the motor mounts the suspension the shifter. By design. Goes back to the, well i want super crisp shifting but no vibrations, and i would like 350whp but easy enough for the wife to drive it! I cannot believe the engineers did not offer this with an auto transmission!? But one thing that makes this fun is putting the pieces together to create what Mazda knows lurks under the surface. it really is nice from the factory and leaves lots and lots of little presents to open if you can figure out to unwrap the bow. The Mazda folks know exactly what they are doing and have done in my opinion. A good point Rich

 

[RichB]

I agree that Mazda knew what they were doing. For them to sell a car with this kind of performance as well as 100% comfort would have made the price through the roof. They had tho choose what was important to them and they did a great job keeping the price down and keeping a lot of the performance. It is up to us to fine tune it to where we want.

 

[ericrapp]

yep, it's quite alot of car. SuperLSD whine be damned! And thanks for the education about it folks. I have learned a good bit. again.

 

[freeflyfreak]

Have we ever figured out just exactly who makes the transmissions for these cars?

If we could get that nailed down, we could *uck off Mazda and contact the trans manufacturer and let them tell us what the deal is.

Does anybody know who makes them.....

BG6 on this page:
http://www.aisin-ai.co.jp/english/products/ff.html