2005 Mazda 3 w/ Manual Tranny Question

sdude2k2000 · Apr 30, 2005

Ok... I've narrowed it down to either Royal Purple or Redline for the transmission lubricant, but my question is... what grade do I go with? The manual states 75w90, but Redline (for exmaple) offers two types... Standard 75w90 -and- the MT-90 (good for Fords I guess). And Royal Purple has their Syncromax (spec'd for Fords on their site) and standard 75w90.

I'm a n00b when it comes to this stuff... so if you guys can help me out, I'd appreciate it.

drive it forever · Apr 30, 2005

While a good product, Redline is way over rated in my experience of using it. I would buy and use Royal purple before Redline. I bought some Specialty Formulations gear oil and have been happy with it, check it out, he is a site supporter.

rpn453 · Apr 30, 2005

Redline seems to encourage the MT-90 over their regular 75W-90 gear for trannies, so I put it in my Mazda3 last fall and I've had pretty good results. It's thinner than the factory fill in cold weather, and works just as well when warm. I actually expected it to be better though, so I was a little disappointed. I'll try something else at 100,000km, just out of curiosity, but I have no complaints.

From Redline's website:
"75W90 Gear Oil can be used in many transmissions and transaxles; however, other Red Line lubricants have better frictional properties for rapid synchronization."

http://www.redlineoil.com/products_gearlubricants.asp?subcatID=18

noob · May 1, 2005

RP Synchromax is WAY too thin for your application. It's one of the thinnest MTFs available. Go with MT-90 or SF MTL-P.

Bror Jace · May 1, 2005

noob beat me to the punch.

When selecting a gear oil for your application, you should find out the thickness of the factory-recommended oil and make a list of those in the same genral weight range. That would have gotten rid of RP Synchromax, Pennzoil synchromesh, etc ...

Then, move those fluids specifically engineered for synchronized manual transmissions to the top of your list.

So, for a 90 weight oil, I'd go with Red Line Oil MT-90 or Specialty Formulations MTL-R.

--- Bror Jace

unDummy · May 1, 2005

MTL-R
MT-90 or 75w90ns
Maxgear 75w90 over synchromax!

Amsoil also has some fluids with the GL4/GL5 specs!

04SpecV · May 1, 2005

Why do people keep recomending Royal Purple Synromax on the Nissan boards. My tranny specifies a 75W85. Clearly the Synromax is WAYY too thin for this. But people seem to be having good results from it???? I don't get it. Where to people come up with this crap.
I'm currently running 1 Quart Redline mt90, about 1.5Quart MTL.. Trans doesn't shift that great, maybe slightly better than the stock fluid.

sdude2k2000 · May 1, 2005

Is it really worth it to run a synthetic in the gearbox? So far... the MT-90 is the most appealing to me, but does it truly offer benefits? If so, what are they?

I really appreciate all this feedback!

crossbow · May 1, 2005

sdude,

Mazda is already running a syn in the gearbox. You wouldn't want to replace a syn with a dino oil would you?

Considering how infrequently gear oil is changed (compared to engine oil), you should always use the best fluid available for your application.

I'd run MTL-R myself from speciality formulations. Its cheaper to order a gallon then 3 qts.

TomH · May 1, 2005

quote:

Originally posted by crossbow:
sdude,

Mazda is already running a syn in the gearbox. You wouldn't want to replace a syn with a dino oil would you?

You sure about that? I had heard that the factory fill is a semi-syn fluid.

crossbow · May 1, 2005

Ya we confirmed it about 2 months ago. I can go and pull the type and data for you if you want. Might take awhile.

TomH · May 1, 2005

quote:

Originally posted by crossbow:
Ya we confirmed it about 2 months ago. I can go and pull the type and data for you if you want. Might take awhile.

No need. It just seems odd to me that Mazda would fill the tranny with syn from the factory, yet not recommend syn as a replacement.

crossbow · May 1, 2005

Mazda doesn't recommend syn because they don't want to spend the money testing every possible solution.

Its the same reason they'll try to void your warranty for installing a short shifter...that they sell.

Think right/left brain syndrome, but at a corporate level. Two different concepts, with no cross communication.

rpn453 · May 2, 2005

quote:

Originally posted by sdude2k2000:
Is it really worth it to run a synthetic in the gearbox? So far... the MT-90 is the most appealing to me, but does it truly offer benefits? If so, what are they?

I used it because dino oil gets very thick at -40C. The Redline still thickens a lot, but not quite as bad as the factory stuff. I was actually hoping for more of an improvement though.
If I wasn't in a cold climate, I don't know if I'd bother with the synthetic.

HardbodyLoyalist · May 2, 2005

Does your manual specify GL-4 or GL-5?

There's a difference. Some trannies can handle GL-5 and some cannot. If your manual specs GL-4, by all means, don't assume you can run GL-5.

MT-90 is GL-4. The Specialty Formulations products are (I believe) dual-rated.

TomH · May 2, 2005

quote:

Originally posted by HardbodyLoyalist:
Does your manual specify GL-4 or GL-5?

Mazda states thae tranny can use GL-4 or GL-5. AFAIK, it doesn't have to be dual-rated.

Bror Jace · May 6, 2005

04SpecV: "Why do people keep recomending Royal Purple Synromax on the Nissan boards. My tranny specifies a 75W-85. Clearly the Synromax is WAYY too thin for this. But people seem to be having good results from it???? I don't get it. Where do people come up with this crap?"

I have no idea.

I've been on a few Nissan boards recently trying to shake some sense into people ... same with a couple Honda boards. I see people recommending RP Syncromax as well as Pennzoil (or GM) syncromesh and these fluids are just too darn thin for these transmissions.

Some trannies seem to shift very well with these thinner fluids ... but I have to believe this is coming at a high price ... increased wear. Only time will tell for sure.

--- Bror Jace

unDummy · May 7, 2005

Some recommendations are based on "you try it" and post the results. Others just don't read the owners manual for fluid weight 'recommendations'.

Mazda for years has given the vehicle owner a choice on the GL4/GL5 fluids. Most of the synthetic 90wt fluids work great.

Nissan has almost always spec'd a GL4 90wt with a recent move(TSB) to 85wt oils.

The real question is whether a thinner STOUT MTF would work as well as a PATHETIC thick MTF. I guess(or hope) that the boutique gear oil additive chemistry in the thinner MTFs might be better then those thicker OEM gear oils.

Also, to thicken an oil, some recommend the ol' 50:50 mix to more closely match the OEM fluid. Read the product specs, compare them to SAE J306, compare them to the OEM recommendation, and mix away.
I find that a mix of 75%MTL and 25%MT90 works better then the 50:50 everyone trys when homebrewing a 75w85 fluid.
The same formula can be tried for RoyalPurple's Syncromax and Maxgear. I too believe Syncromax is way too thin for 85wt transmissions.
Pennzoil Synchromesh can probably be thickened with Pennzoil's own GL4/GL5 90wt gear oils in the same way.

Besides OEM fluids, there is at least ONE aftermarket 75w85 gear oil brand mentioned in this thread that should be tried in those Nissans.
Also, what does Hyundai use in their better shifting identical 6-speed Tiburon/SpecV tranny?

Bror Jace · May 7, 2005

"I find that a mix of 75%MTL and 25%MT90 works better then the 50:50 everyone trys when homebrewing a 75w85 fluid."

Since many Nissan guys seem to use Red Line MT-90 all by itself, I think cutting it with 25% MTL is probably a significant improvement ... but you might be right that a 75% MTL mix is the way to go.

"The same formula can be tried for RoyalPurple's Syncromax and Maxgear. I too believe Syncromax is way too thin for 85wt transmissions.
Pennzoil Synchromesh can probably be thickened with Pennzoil's own GL4/GL5 90wt gear oils in the same way."

I just recommended this same approach on the V-board. I have my biases, but I always like to propose more than just one solution so people don't suspect I'm merely a shill working for one company or another.

"Also, what does Hyundai use in their better shifting identical 6-speed Tiburon/SpecV tranny?"

Good question ... but the better shift feel is attributed to the better shifter the Hyundai uses.

--- Bror Jace

2005 Mazda 3 w/ Manual Tranny Question

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