For those that have LSD noise after switching to MT90

[)EIB(]

Thought I should share this here just for reference. Below is the official response I got from Redline in regards to LSD noise after switching to MT90 and adding Friction Modifier to reduce the noise:

------------------------------------------------------------------------
Below are the results from the Red Line Oil web site Application Request Form.

It was placed on 12/11/2008 10:25:47 PM.

Application Request Form Information
-----------------------------------------------
Name : --------
Email Address : -----------------
Address : ------------------
Address 2:
City : --------
State : ---
Zip : -------
Make : Mazda
Model : Mazdaspeed3
Year : 2007
Engine Type : 4 cylinder turbo direct injected
Differential Size/Type : Torsen Cone Type Super LSD
Transmission Type: 6-speed transaxle
Issues : I've recently replaced the transmission fluid with MT90 which is recommended for my vehicle. However, I'm experiencing LSD noise under low gear low speed tight turning in cold operating temperature. The transmission is shifting perfectly smooth under all condition. The only problem I have is the LSD noise after switching to MT90. I understanding your company makes a friction modifier that can be used with the MT90. What are the effects of adding friction modifiers to the MT90? Will it eliminate the LSD noise at the expense of shifting quality? If I choose to add the friction modifier, what ratio of mixture is appropriate for my application? If I choose NOT to add the friction modifier, will the LSD be damaged or its longevity shortened due to the noise? What is your recommendation in regards to whether or not to add the friction modifier?


)EIB(,

Thank you for contacting Red Line Oil, the cone type limited slip units are generally not particularly prone to chatter. The Friction Modifier can be added to the MT-90 though too much will be detrimental to the shiftability. If you wanted to add some I wouldn't exceed about 1% by volume, less than an ounce. The chatter is more of an annoyance than being harmful, I wouldn't expect it to affect the life. If the noise isn't annoying, then I would just live with it, if too annoying then I would increase the slipperiness of the fluid slightly, you could decide that.

Regards, Dave
Red Line Oil
-------------------------------------------------------------------------

After receiving this response, I decided not to add the friction modifier and just live with the noise.

[Abilor]

Good to know. I'd wear earplugs too.

[amascio]

I notice you mention cold weather. In warmer weather does the noise stop?

[AGspeed3]

I've had MT-90 in for 15k miles or so. Same issue - cold mornings until the engine warms up I get the same thing. Wasn't as bad when the fluid was new, but has gotten worse over time. Noise stinks, but the shifting when cold is still better than stock fluid.

[)EIB(]

amascio: for the most part, the noise happens only in cold operating conditions. Once the transmission warms up, the noise either goes away or barely noticeable with the steering wheel at full lock moving at very low speed (like driving in a parking structure, for example)

AGspeed3: I've had the fluid for a few thousand miles and I noticed the noise has gotten slightly worse as well. But like you said, the shifting quality is just so much better than the stock fluid under all condition that I would rather live with the noise than switching back....

[dan7225]

i've been using mt90 for a few years in my cars.
honestly ever since i've put it in the ms3, 2nd gear grinds a lot (revving & double clutching shouldn't be the answer to daily driving)
i have added about 5 ounces of frinction modifier (oreilly auto parts brand), and no change with the noise.
people have always seemed to rave about MT90 gear oil. i've probably spent over $250 on it in my last 2 cars. i dont think it works that great. i always seem to have some kind of gear grinding problem with it.
one thing i've noticed is that once you use it, going back to regular gear oil is a mistake. the shifting really sucks after the switch back to regular. sounds like a contradiction right? i just know the oil that came stock in both cars seemed to shift all gears just fine. no whine no grind. if i switch back to regular oil in the ms3 i expect it will probably be worse than with MT90.
i'm honestly thinking about going with redline heavy duty shockproof oil.
i've heard people rave about it after it warms up. maybe atleast then i wont be grinding gears.

[amascio]

If you have the $$$ here's what I am using with great results...Ford part # XT-M5-QS.

I was running Redline MTL to get better shifts and it WAS better, but kinda out of spec (70W80). After sifting the web on the XT-M5-QS and finding out that it was doing well, I tried it.

It is great! Shifting at any temp is excellent with the 1-2 gear grind a thing of the past. My trannie is virtually silent now which is assuring. It has been in my box for 8k miles so the stuff is no flash in the pan.

Google XT-M5-QS and look for the Ford Chemicals web page and read about it.

It was developed in Germany for some difficult shifting Getrag FWD boxes that Ford had in production.

I paid $19.25 a quart but I have seen it on the web for as low as $15 a quart.

For a 75w90 GL4 weight oil it seems thin but it is recommended by Ford for all their manual boxes that require 75w90 GL4. Ford Chemical has other oils in the 75w90 range but the XT-M5-QS is their TOP oil.

It is so well engineered that Ford considers it suitable for lifetime fill.

It doesn't seem to be wearing out so it's going to stay in for quite some time......

Cheers all!

[amascio]

An addition to my post...

It doesn't get really cold here in the Houston area so stating that the XT-M5-QT works great in all temps, in my case, might be a stretch - Houston's winter temps rarely go below 40F.

However, today it was uncharacteristically cold here, 30F, so I made sure to make the car do some sharp, low speed turns right after firing her off - no LSD noise whatsoever. I put the car in my cul-de-sac and made it drive slow in both directions at full cock and the lube is keeping things quiet.

Now at -20F I couldn't say whether the stuff would make noise or not, I do know that it's good to go just below freezing.

And at 30F, the shifting was fine - any manual trans in cool weather will have some notchiness to it and my car is no exception, but it no longer grinds the 1-2 shift ever and the cold notchiness is gone in less than a minute.

I attribute the success of this product to it's exellent base oil and exotic add pack - German lubrication engineers rarely underdo anything.

Cheers all!

.

[tru-boost]

My trans has had mt90 for anout 20k now. It doesnt make noise nut the shifts are tough for a few minutes in cold temps. DO NOT USE ANY FRICTION MODIFIER im this transaxle. It will ultimately kill your synchros and in all honesty this diff type works best without it. Just dont do it!

[07speed3]

im running royal purple and i get that noise also, i dont think that it had friction modifier.

[tru-boost]

Rp has modifier in it from the get go. Its no good for this tranny.

[amascio]

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.....

[tru-boost]

It doesnt matter who makes it, what matters is whats in it. It has a conical type limited slip and triple con synchros for gears 1-3 and double cone for the rest. That means the diff needs no friction modifier and if added it will over te destroy your synchros.

[amascio]

At one point in time it was thought to be this transmission:http://www.getrag.de/en/250 Who really knows...

[08_MS3_GT]

i've got the same noise issues - with Amsoil MTG transmission fluid. it doesn't seem to go away when warm. i have 3qt of MT-90 on-hand and was considering swapping it in.

is this sort of noise "normal"??? i mean, i wouldn't expect high-grade GL-4 synthetic oil to damage an LSD. i can easily put up with the noise if i'm fairly certain that it's not indicative of a part failure.

i swapped winter tires on @ the same time i swapped in the fluid, so i've thought that the tires were to blame. i guess the noise has been there the whole time, and, if MT-90 is causing it as well, there's no reason for me to switch?

[)EIB(]

After some mileage with the MT-90, I've noticed that the noise is there even when the gear box is warmed up. But the noise is less intense then when it is cold.

According to the response from Redline, the noise is more of an annoyance than harmful. So if it's really a concern, you might want to trying putting in a very small amount of friction modifier to see if that would eliminate the noise. Amsoil also makes a friction modifier for use with their gear lubes to reduce LSD noise, which is called Amsoil Slip Lock. Give that a try and see how it goes.

I wouldn't switch to MT90 in your case since you already have Amsoil MTG which is a good tranny lube and based on my experience the MT90 would result in the same noise.

[1speed3]

I work for Johnson Subaru and by trying every oil / diff fluid in the world i will tell you there is nothing better then Amsoil. I have had royal purple, greddy fluid, redline fluid, mobile one, Valvoline race oil, and many more. I will tell you for performance and longevity Amsoil is the best by far. It is the best for the money hands down. I had this same sound on cold mornings and it drove me nuts. It happened with royal purple and redline for me.

SWITCH TO AMSOIL ! Best thing you could ever do for yourself.

[Fat_Dave]

has anyone tried pennzoil syncromesh? i have it in my trans in my zx2 and it shifts like butter

[pjb1180]

Move south

[john blutarski]

I'd like to add that the same thing happened in my WRX. As soon as I switched from the factory fluid fill to Redline, I got much more gear whine. It never went away after that no matter what fluids I tried and I tried several even a refill of the stock stuff. The good news is it still shifted and drove perfect for 20k miles till I traded in the car.

[john blutarski]

After some mileage with the MT-90, I've noticed that the noise is there even when the gear box is warmed up. But the noise is less intense then when it is cold.

According to the response from Redline, the noise is more of an annoyance than harmful. So if it's really a concern, you might want to trying putting in a very small amount of friction modifier to see if that would eliminate the noise. Amsoil also makes a friction modifier for use with their gear lubes to reduce LSD noise, which is called Amsoil Slip Lock. Give that a try and see how it goes.

I wouldn't switch to MT90 in your case since you already have Amsoil MTG which is a good tranny lube and based on my experience the MT90 would result in the same noise.

exactly

[08_MS3_GT]

After some mileage with the MT-90, I've noticed that the noise is there even when the gear box is warmed up. But the noise is less intense then when it is cold.

According to the response from Redline, the noise is more of an annoyance than harmful. So if it's really a concern, you might want to trying putting in a very small amount of friction modifier to see if that would eliminate the noise. Amsoil also makes a friction modifier for use with their gear lubes to reduce LSD noise, which is called Amsoil Slip Lock. Give that a try and see how it goes.

I wouldn't switch to MT90 in your case since you already have Amsoil MTG which is a good tranny lube and based on my experience the MT90 would result in the same noise.

thanks for the insight - i just wanted to make sure i wasn't destroying my drivetrain.

i'll keep the Amsoil in there - the shifting is smooth, and, if the noise is harmless, then i don't have any worries. especially if all other fluids also make noise.

1speed3 - you think that MTG (Amsoil) is better than MT-90 (Redline)? I figured that they were comparable but that MT-90 was better because it's so darn common.

[amascio]

has anyone tried pennzoil syncromesh? i have it in my trans in my zx2 and it shifts like butter

Fat Dave - you're accomplishing what I did when I started using Redline MTL in my trannie. The MTL and Pennzoil Synchromesh are considerably thinner than the 75w-90 weight that Mazda specs and because they are thinner the synchros have less fluid thichness working against them as they try to do their job.

I ran the MTL for around 17k miles with no problems whatsoever to it appears to be up to the job of fully lubricating the trans' innards. And being thinner cold shifts are MUCH better than MT90. If the XT-M5_QS weren't doing so well, I'd be right back on the MTL!

[bani]

At one point in time it was thought to be this transmission:http://www.getrag.de/en/250 Who really knows...

the ms3 transmission is the aisin bg6. not getrag.

http://www.aisin.com/product/automotive/drivetrain/mt.html

[Nliiitend1]

If you have the $$$ here's what I am using with great results...Ford part # XT-M5-QS.

I was running Redline MTL to get better shifts and it WAS better, but kinda out of spec (70W80). After sifting the web on the XT-M5-QS and finding out that it was doing well, I tried it.

It is great! Shifting at any temp is excellent with the 1-2 gear grind a thing of the past. My trannie is virtually silent now which is assuring. It has been in my box for 8k miles so the stuff is no flash in the pan.

Google XT-M5-QS and look for the Ford Chemicals web page and read about it.

It was developed in Germany for some difficult shifting Getrag FWD boxes that Ford had in production.

I paid $19.25 a quart but I have seen it on the web for as low as $15 a quart.

For a 75w90 GL4 weight oil it seems thin but it is recommended by Ford for all their manual boxes that require 75w90 GL4. Ford Chemical has other oils in the 75w90 range but the XT-M5-QS is their TOP oil.

It is so well engineered that Ford considers it suitable for lifetime fill.

It doesn't seem to be wearing out so it's going to stay in for quite some time......

Cheers all!

This is the stuff I used to use in my Focuses, and it's definitely a top notch fluid.

I had intended to use it in my MS3, and hearing you say that it's performing admirably has only cemented my resolve to do so.

:)

[RichB]

When I first changed my fluid I heard this noise as well. To get rid of it I had to add a full 4 oz tube of friction modifier (about 4% by volume). This was done by following the instructions which say add modifier untill the chatter stops. I don't know where they got the 1% from.

You will be fine with this set up as your daily driver. If you are taking your car to the track, the modifier is not recommended. Just take note that adding the modifier will require you to change your fluid more often.

I have been running MT-90 with friction modifier for about a year now and love it.

[akrisamar]

I added about 2 ounces of Redline's friction modifier to MT-90 and the LSD noise is gone!

[tru-boost]

Friction modifier kills synchros. Even a small amount. It will make the diff noise stop, but over time it will cause the synchros to slip and gears to grind. I add nothing to my MT 90. I did get a little noise the first couple 100 miles while turning but it stopped. Also FYI there is no friction modifier in it from mazda.

[RichB]

When I put MT-90 in I didn't have a friction modifier for like 10K miles and it still made noise on low speed turns.

If you add friction modifier, you should be fine if you just change the fluid more often.

[///M Compact]

This is the stuff I used to use in my Focuses, and it's definitely a top notch fluid.

I had intended to use it in my MS3, and hearing you say that it's performing admirably has only cemented my resolve to do so.

:)

That's what I use; my transaxle isn't dead silent in tight corners but the fluid improved the shift quality quite a bit.

[marathonman08]

i just added MT-90 this weekend and it made a huge difference in the smothness of the shifting... as for the sound... Get a TRZ tranny mount and you won't even hear them because of all the other wonderful transmission sounds. Problem solved:D

[fastdreams]

I have Motul Gear FF or something like that. Shifts great but also has the lsd noise noticeable at parking lot speeds while turning.

Glad to see it's not a big deal mechanically!

[Pololo_MS3]

Yeap....Same issue with mine. MT-90 for 10K miles now and although the shift is better than stock, the noise drives me crazy.

I even took it back to the dealer and they said: "Did you change the oil in the tranny to RedLine Synthetic?"... I was .. yes I did... "Then that's the problem"... They added a friction modifier from Ford and told me not to worry about it...

"It indeeds sounds bad but it's better than the "stock oil"... so don't switch back..." This was the Service Manager who is pretty good and knows me well.

Hope this helps
Carlos

[destrux]

I work for Johnson Subaru and by trying every oil / diff fluid in the world i will tell you there is nothing better then Amsoil. I have had royal purple, greddy fluid, redline fluid, mobile one, Valvoline race oil, and many more. I will tell you for performance and longevity Amsoil is the best by far. It is the best for the money hands down. I had this same sound on cold mornings and it drove me nuts. It happened with royal purple and redline for me.

SWITCH TO AMSOIL ! Best thing you could ever do for yourself.

I have the Amsoil MTG in mine and it makes the noise.

[enganear]

Cone clutch lsds make a moaning sound when turning sharply at low speeds. Get used to it like clanging bpvs.

Friction modifiers were developed to prevent chatter in plate clutch lsds by increasing "slipperiness".

Cone clutch lsds and gear synchronizers require friction to work. Adding friction modifier to the MS3 tranny will result in degraded performance of the synchronizers and lsd. Your gears will clash during shifts because the synchronizers cannot exert enough torque on the chosen gear because it is too slippery. The quiet lsd is now just along for the ride because it cannot build enough torque in its cone clutches to be effective.

I feel sorry for those of you that have added friction modifier to the MS3 tranny.

If someone asks you "what is that moaning noise when turning at low speed?" just tell them proudly that your car is equipped with a cone clutch limited slip differential and that is just the sound they make. If you perceive this as a flaw, you should sell your MS3 and put your candy ass in a Camry.(sad1)

-enganear

[)EIB(]

good call! I've put on over 10k miles since I switched to MT90 without any friction modifier. Although the moan at low speed sharp turns does get annoying at times, the shift quality is so good that I think that annoyance is just a small trade off.

[RichB]

I both agree and disagree with enganear.

If you are tracking your car, you should NOT be using friction modifier.

For a daily driver I think adding some modifier is fine, but don't go overboard with it. I added modifier to my tranny to soften up the noise. You can still hear it on low speed turns, but it doesn't sound as harsh as it did without the modifier.

My tranny still shifts smooth as silk and I can feel my LSD locking up when I want it to.

If you are trying to figure out what to do, it's all up to you because it's your car. Keep in mind that if you do add modifier. You need to change the fluid more often!

Thats all I got.

[ericrapp]

I am glad i read this as iwas about to switch from redline to purple. And will not now. I am having issues with 3rd under extreme conditions. This info has been helpful thanks folks! I will consider the amsoil. Which one specifically please?

[hectik1]

I will never use Redline MT90 in my car....period.

[enganear]

I will never use Redline MT90 in my car....period.

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

[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