Concerned with MT90

[bacarl]

Hey guys, I've seen this mentioned all over the place but haven't found any good comments about it or any resolution. I'm talking about the gear whine that people notice after switching to Redline MT90. I like the silkier/smoother shift feel, but like many others I hear a low whine at slow speeds and/or while cornering.

I've heard horror stories about using incorrect trans fluids and am wondering if the MT90 is doing more harm than good. Can anyone who's educated in trans and trans fluid speak to this? I am far from an expert.

I know AutoXRacer and Enganear among many others have spoken highly of the MT90, perhaps they could comment? Thanks guys, I'm just trying to make sure I'm not destroying my LSD by gaining a titch of shifter feel.

Here are a couple quotes I found randomly describing the issue...

Originally Posted by crypt0wind (M3F.com) ...I replace mine gear oil with a quality synthetic 75-90w and had a "wah wah wah" noise when low speed turning from the LSD. Had the dealer replaced with stock 75-90w and fiction modifier. The noise went away.

Originally Posted by Frequentflyer I put MT90 in my tranny last week. I've got mixed feelings. Although it may feel slightly smoother most of the time, I get an occasional notchiness and I still get the 3rd gear grind during quick shifting, even with Corksport MM inserts. I can't tell whether it's the tranny or just driver error. I've driven nothing but stick for the past 13 years, but it seems easy to try to jam this tranny in between 1st and 3rd when shifting quickly, which I think attributes to the grind. Anyway, I also notice more gear noise with this stuff. It's kinda like a whine the changes pitch with RPM. Seems louder while going slow and around turns. I don't hear it at all during high speed cruise. I'm wondering if the LSD doesn't like this stuff. Seems as though enough people use it though.

[SSinstaller]

The thinner slicker oil will attenuate the normal niose forom the tranny much less than conventional oil. I didn't notice any extra whine when I switched to MT90, but it whines like a cheap stereo now that I have the AWR tranny mount...

[Lymerock]

Ive autocrossed 60 events over 2 years on MT-90
been great stuff for me, perhaps a tad more noise, but no ill effects and the lsd seems to work better than with the stock oil

[gofast]

i noticed more whine too after throwing in the mt90. for a while i wondered if i somehow didnt put enough in.

[Zeya]

My tranny is still stock and I haven't put on my rear mount yet either. I hear the tranny whine at low speeds, and I think it's normal. So you have to consider that if you didn't do the swap, you might be hearing sound anyway. Of course it's hard to gauge what degree of whine you're referring to over an internet forum.

Edit: Actually let me clarify. I hear a whining sound when at high rpms in a low gear, such as first. If I somehow downshift into first (say on a tricky steep hill or something, whatever) at too high of a speed, it'll whine.

[Awddsm97]

Personally I use Redline Light shock proof Blue.

[Unoriginalusername]

i haven't heard any more noise or had any issues with it.... then again if i didn't watch it go in with my own eyes its pretty hard to tell a difference that its even there

[superskaterxes]

hmm this has me a bit concerned as i am getting ready to do this next week. would this be any different for the MS6 seeing as how we have different PT's?

[Meder]

I hear more transmission noise with mt 90. I do not seem to get any sort of whine though. I do hear more shifter/gear changing action such as clicking into gear every now and then.



One thing that I seem to get is that in the morning before the car has really warmed up, even if I take it slow and double clutch i sometimes get a scratch or crunch into gear. I am being easy on the shifter and letting it go into gear when it wants, its pretty odd. I am hoping this is just part of the mt 90 taking longer to warm up, because once the car is good to go it shifts awesome.

[builthatch]

Originally Posted by bacarl am wondering if the MT90 is doing more harm than good.

you will be fine using mt-90. don't worry. the internet is enough to drive people crazy sometimes, don't let it get to you...

people are hyper sensitive to anything that happens and where they place the blame can suddenly grow 'net legs like no other.

again, you'll be just fine.

[Frequentflyer]

Yeah, you will be fine, BUT you will most likely hear more gear noise. It's definitely not my imagination.

[gofast]

Originally Posted by Frequentflyer Yeah, you will be fine, BUT you will most likely hear more gear noise. It's definitely not my imagination.

+1 ive had it in for about 10k and havent had any mechanical issues. the whine i hear is mainly when downshifting not a constant. i should clarified a bit on that when i said i heard a whine

[kingpin748]

I haven't had an issue but I have heard others complain about that. Just make sure you get GL-5.

[subparpunk03]

Originally Posted by kingpin748 I haven't had an issue but I have heard others complain about that. Just make sure you get GL-5.

NO! GL-4...

BAD kingpin!

[bioevolve]

I use Mobil Synthetic 75W-90 and I hear less whine.

Here's a good test of gear oils, MT-90 is not listed but Redline Synthetic 75W-90 is listed.

http://www.synthetic-oil-tech.com/Ge...te%20Paper.pdf

I chose Mobil cuz it's in the middle of most of those tests. AMSoil got best score and Lucas got dead last.

[DreSEL]

I have used MT-90 in my sentra for 8 years without a single problem. And used it in my turbo SE-R as well.

[bykeryder4life]

Originally Posted by kingpin748 I haven't had an issue but I have heard others complain about that. Just make sure you get GL-5.

I'm pretty sure gl-5 will destroy our tranny. we gotta have the gl-4 on the MS3

[subparpunk03]

Originally Posted by bioevolve AMSoil got best score and Lucas got dead last.

Thats why I use amsoil oil, transmission fluid, and brake fluid. A lot of people haven't heard of it, but its pretty much like liquid sex for your engine/transmission/brake lines.

HIGHLY reccomend it, but don't take my word for it, do some research, amsoil is the top performer in almost every test I've ever read.

Their brake fluid might not be as good as ATE or motul... I haven't read too much about it, but I gotta rep the Amsoil

[FCmaniac]

Coming from a WRX, the MS3 tranny seems quiet. I noticed the same issue when switching from the stock fluid to Redline in the WRX.... much more whine. And it never went away after trying several different fluids. Overall it performed better for me though so I dealt with it. I believe most of the noise I was hearing was a combination of drivetrain lash and the LSD for some reason seemed quietest with the stock fluid.

[ElBartoRex]

Originally Posted by FCmaniac Coming from a WRX, the MS3 tranny seems quiet. I noticed the same issue when switching from the stock fluid to Redline in the WRX.... much more whine. And it never went away after trying several different fluids. Overall it performed better for me though so I dealt with it. I believe most of the noise I was hearing was a combination of drivetrain lash and the LSD for some reason seemed quietest with the stock fluid.

+1 from another former Subie owner. I remember the night I first test drove a MS3 and then got back into my WRX. It was like, wow is my transmission really this crappy? The MS3 glides like butter compared to the WRXs 'box of rocks' as it has been called.

I have had MT-90 in my car for about 10,000 miles as well and it endures a lengthy daily highway commute with no issues.

For the record, all Red Line MT-90 is 75w90 weight GL-4 oil. They do not make an MT-90 GL-5

[kingpin748]

Originally Posted by subparpunk03 NO! GL-4... BAD kingpin!

Whoops. My bad.

Better just check the owners manual instead of listening to some asshole on the internet.

[Haltech]

Ive also heard of someone using Redline MTL in a MS3, although its way to thin to be using in our trannies. So be cautioned there. its about as thick as ATF fluid.

[bacarl]

Thanks for all the great replies guys. I just talked with some buddies yesterday about GL-4 vs GL-5 so I'm up to speed on that. I'll double check the manual and the MT90 bottles to be sure they jive.

Originally Posted by Zeya My tranny is still stock and I haven't put on my rear mount yet either. I hear the tranny whine at low speeds, and I think it's normal. So you have to consider that if you didn't do the swap, you might be hearing sound anyway. Of course it's hard to gauge what degree of whine you're referring to over an internet forum. Edit: Actually let me clarify. I hear a whining sound when at high rpms in a low gear, such as first. If I somehow downshift into first (say on a tricky steep hill or something, whatever) at too high of a speed, it'll whine.

I know the whine you're talking about Zeya. I hear that too under the same circumstances. The noise I'm worried about never ever happened, then the day I put the MT90 in, I pull out of the driveway and I hear "rawrrawrrawr" as I turn onto the street.

Originally Posted by DreSEL I have used MT-90 in my sentra for 8 years without a single problem. And used it in my turbo SE-R as well.

This is exactly what I'm worried about though... Every trans is different. Just because it works great in a Sentra or in a WRX doesn't mean a MS3 trans will like it. The synchros could be weaker or the metals softer, which makes them suseptible to GL-5 lubes. Or perhaps the LSD needs a specific weight oil that the other transmissions don't require.

Originally Posted by ElBartoRex For the record, all Red Line MT-90 is 75w90 weight GL-4 oil. They do not make an MT-90 GL-5

Thanks! This is great info that I was hoping to hear. Like I said I didn't know the difference between GL-4/-5 when I put in the Redline so I didn't read over the bottle looking for that info.

Originally Posted by Haltech Ive also heard of someone using Redline MTL in a MS3, although its way to thin to be using in our trannies. So be cautioned there. its about as thick as ATF fluid.

Thanks Haltech - can you clarify, though? Is "Redline MTL" a specific type of lube that Redline produces or are you describing all of Redline's Manual Transmission Lubricants? As was stated above, MT-90 is a 90wt oil. Hence it should be thicker than ATF?

Thanks again fellas.

[saranya]

Originally Posted by bioevolve I use Mobil Synthetic 75W-90 and I hear less whine. Here's a good test of gear oils, MT-90 is not listed but Redline Synthetic 75W-90 is listed. http://www.synthetic-oil-tech.com/Ge...te%20Paper.pdf I chose Mobil cuz it's in the middle of most of those tests. AMSoil got best score and Lucas got dead last.

interesting test, thanks.

looks like amsoil put everything else to shame. but it seems to be a gl-5, so can't use in our cars since we need a gl-4?

redline here seems like a middle of the road item.

[Haltech]

Originally Posted by bacarl Thanks for all the great replies guys. I just talked with some buddies yesterday about GL-4 vs GL-5 so I'm up to speed on that. I'll double check the manual and the MT90 bottles to be sure they jive. I know the whine you're talking about Zeya. I hear that too under the same circumstances. The noise I'm worried about never ever happened, then the day I put the MT90 in, I pull out of the driveway and I hear "rawrrawrrawr" as I turn onto the street. This is exactly what I'm worried about though... Every trans is different. Just because it works great in a Sentra or in a WRX doesn't mean a MS3 trans will like it. The synchros could be weaker or the metals softer, which makes them suseptible to GL-5 lubes. Or perhaps the LSD needs a specific weight oil that the other transmissions don't require. Thanks! This is great info that I was hoping to hear. Like I said I didn't know the difference between GL-4/-5 when I put in the Redline so I didn't read over the bottle looking for that info. Thanks Haltech - can you clarify, though? Is "Redline MTL" a specific type of lube that Redline produces or are you describing all of Redline's Manual Transmission Lubricants? As was stated above, MT-90 is a 90wt oil. Hence it should be thicker than ATF? Thanks again fellas.

Redline makes a lube called MTL and its mostly used with domestics, such as Fords/Chevy's that use Borg Warner trannies. Unfortunately, someone bought this stuff and used it in there MS3 about 8 months ago or so. Cant remember the SN, but it was on the other forum.

[gofast]

Originally Posted by saranya looks like amsoil put everything else to shame. but it seems to be a gl-5, so can't use in our cars since we need a gl-4?

amsoil has a gl-4

amsoil gl-4

[phantom6294]

Originally Posted by gofast amsoil has a gl-4 amsoil gl-4

If you look closely... the Severe Gear 75W-90 page does state "Can also be used in axles where an API GL-4 lubricant is recommended."

[bacarl]

FYI guys, I checked in the owner's manual last night and it does specify GL-4 for the "with turbocharger" column.

[Phantom]

Yeah make sure not to go with GL5. It will kill your tranny quick. I did some research today and I couldn't find anything to show that GL5 could be used in a GL4 tranny.

The only thing with the MT-90 is there is no friction modifier. That is one of the conserns I am having with ordering it.

So I have a question to those who have the MT-90. Other then reports of the added noise/chatter have you seen any loss of function of the LSD without any friction modifiers? I have 78k Km on my car now and have had some noise/chatter with my tranny for a while now (stock gear oil). Easy 15k Km or more.

Has anyone added any friction modifier to the MT-90?

[DreSEL]

Originally Posted by DreSEL I have used MT-90 in my sentra for 8 years without a single problem. And used it in my turbo SE-R as well.

I understand that the Sentra's and MS3's trannies are different. And just because it works fine in one car, doesn't mean that it will be fine in another. I thought about it after I posted this. But I just checked, and both trannies have the same fluid requirements.
I remember I sent an email to Redline years ago asking them about Shock Proof, and IIRC, thay said they did not recommend it for trannies with synchros. But I've read about people using in their cars with no problem. I've even read about people mixing MT 90 with Shock proof.

The only thing that I can say from personal experience is that I love how smooth the tranny in my old car feels with MT 90. I can't say anything about the MS3 since it still has the stock fluid (although I have 3 bootles ready to go), but like I mentioned before, both transmissions require the same fluid.

[MadOzodi]

I've had MT-90 in my tranny since mid-Feb. From the research I did, I found that you are NOT supposed to add friction modifiers to MT-90 as that's what lessens the effectiveness of the LSD. So, I decided to sacrifice some noise comfort during parking lot speed turns to gain smoother shifting and more traction while squeezing on the throttle exiting 3rd gear turns on the track.

If you're going to add a friction modifier to MT-90, you may as well save your $$$ and not bother with MT-90 at all.

[phantom6294]

Originally Posted by Phantom Yeah make sure not to go with GL5. It will kill your tranny quick. I did some research today and I couldn't find anything to show that GL5 could be used in a GL4 tranny.

I've heard that for years... and more and more, I read sources saying this was a problem initially with GL-5 but should no longer be a problem; I can only find forum posts that GL-5 means eventual death for a "GL-4 tranny." I found some evidence that this issue began with VW owners using GL-5 in their 'GL-4 trannies.'

There was a discussion on the API GL-x ratings:
Gear Tribology and Lubrication - Part I - Bob Is The Oil Guy
Gear Tribology and Lubrication - Part II - Bob Is The Oil Guy

In my 2008 owner's manual, it states that GL-4 or GL-5 can used in models 'without turbocharger.' This, however, could simply mean that it's a "GL-5 tranny" and "GL-4 will work." That said, as I understand it, the original issue was with the extreme pressure additives in GL-5 that were corrosive to soft metals -- of which synchros are generally made. However, I have a hard time believing that the regular Mazda 3s have trannies without synchros or some hardened synchro that would stand up to GL-5 if it were corrosive.

Obviously, I certainly believe in 'better safe then sorry.' If a company provides a GL-4 specific version of a product... why risk it, right?

I'll continue my internet research... for what its worth.

[phantom6294]

So, did some digging... and found the testing publication number for API GL-5; STP-512A. It is a copyrighted document and was available from API for $55 or $25 download. However, I was able to view some of the pages of the actual publication via Google Book Search. (Hopefully the link works outside of my browser.)

Any ways... I found the following text to be a particular interest:

"API GL-4 and and GL-6 service designations are considered to be obsolete since the equipment used in performing one of more of the required test is no longer available. While the original type of testing cannot be performed on new oils, lubricants of there types (API GL-4 and GL-6) may be available via previously approved lubricant forumlations."

Also of interest is:

"API GL-5 Bench Tests

Copper Corrosion (ASTM D 130)

Copper containing mechanical components such as thrustwashers and sychronizers elements, may be found in axles and transmissions where gear lubricant is specified. Consequently, it is important that these lubricants are equally compatible with both copper alloys and ferrous metals. ATSM D 130 - Method for Detection of Copper Corrosion from Petroleum Products by the Copper Strip Tarnish Test (Vol. 05.01) - is used in combination with appropiate limits to define the degree of copper corrosion protection provided by gear lubricants."

Unfortunately, that paragraph is at the end of the page, and next two pages aren't viewable in Google Book Search.

[bacarl]

Good stuff man. Yeah part of the reason I was worried about this to begin with is, a co-worker of mine who's a mechanic and engineer and all-around bright guy, told me a story about his Nissan modding days. There was a change to the trans that were going into 90's Z cars. Guys were putting the newer, "perceived better" lube into their older trans and the sychros were being destroyed. Appently no one knew what the hell was going on, but it sounds like a GL-4 vs -5 issue. When he told me the story I didn't know there was a difference so it was pretty alarming.

The way I see it, any noise that begins after I make a change to non-factory parts/equipment is a bad noise. I'm looking at it more as an indication that something's wrong inside the trans, rather than just an annoying NVH issue. The noise itself doesn't bother me since it occurs infrequently. What bothers me is potential damage to my diff due to the lack of friction modifiers or whatever it is. If my diff seized up after 30k miles I'd be bummed!

Thanks to builthatch and the guys assuring me I'm safe, but does anyone know just what it is that is making the noise? The only diff I've seen up close & apart was a center diff from a Subaru that we used in our Formula SAE car. It was full of gears, so I suppose a great deal of gear whine would be produced if a lube was too thin or somethin.

[FCmaniac]

I'm sticking with the stock fluid. It shifts just fine.

[ericm979]

The noise is from the LSD. The friction modifier isn't for the transmission or differential gears- it's for the LSD clutch pack. More modifier == less clutch friction == less lockup. Too much lockup would presumeably wear out the LSD clutches prematurely.

From reading the Redline MT-90 specs, it has some friction modifier in it. Not all GL-4 synthetics do.

I recently put Amsoil GL-4 in my MS3 and it started making the same noise you are describing. I emailed Amsoil tech support who told me that their oil does not have friction modifier in it. I just picked up some MT-90 to replace the Amsoil and I am hoping that will take care of it. So I am somewhat concerned that your car is making the LSD "chatter" noise with Redline MT-90.

[phantom6294]

Originally Posted by ericm979 I recently put Amsoil GL-4 in my MS3 and it started making the same noise you are describing. I emailed Amsoil tech support who told me that their oil does not have friction modifier in it. I just picked up some MT-90 to replace the Amsoil and I am hoping that will take care of it. So I am somewhat concerned that your car is making the LSD "chatter" noise with Redline MT-90.

Not trying to specifically push Amsoil products, but Amsoil does have a friction modifier that may be worthwhile before spending money on completely changing the fluid.

AMSOIL - Slip-Lock Differential Additive (ADA)

[AutoXRacer]

Originally Posted by Phantom Has anyone added any friction modifier to the MT-90?

Never ever add friction modifier to a synthetic. That is to be used with dino oil!!!!

Friction modifiers are for friction (clutch) type LSD...being used with dino oil.
The modifier is like concentrated synthetic fluid.

When you purchase Red Line or any other "true" synthetic gear oil and/or tranny oil, it does not require any other additives!! Just buy the correct formula for your application.

I've been running MT-90 for 25K miles and no issues, no added noise, nothing...that includes daily driving and 3-4 autocrosses a month; in addition to occasional drag racing.

[Domino81]

Originally Posted by bioevolve I use Mobil Synthetic 75W-90 and I hear less whine. Here's a good test of gear oils, MT-90 is not listed but Redline Synthetic 75W-90 is listed. http://www.synthetic-oil-tech.com/Ge...te%20Paper.pdf I chose Mobil cuz it's in the middle of most of those tests. AMSoil got best score and Lucas got dead last.

Interesting stuff. Royal Purple is good stuff, but the copper test that it failed concerns me. And I personally use Redline. Never had an issue.

[ericm979]

Originally Posted by phantom6294 Not trying to specifically push Amsoil products, but Amsoil does have a friction modifier that may be worthwhile before spending money on completely changing the fluid. AMSOIL - Slip-Lock Differential Additive (ADA)

Yea I know. I'm not entirely happy with the shifting with the Amsoil and I am hoping based on past experience that the Redline will be better.