Oil for the gearbox Fiat X1/9
- Thread starter Dmitriy
- Start date
phillips82
True Classic
GL-1 non EP is still made. We keep it on the shelf and most farm and tractor supply stores keep it in stock.
DanielForest
True Classic
GL-1 is still available but some people think it is a little bit dated. Don't use GL4 or GL5. Some transmission experts will suggest MTL Redline or equivalent. More expensive but it will increase longevity of the gears.
Steve Hoelscher
True Classic
GL-1 is outdated by modern lubricants. The preferred gear oil is Redline MTL. As an alternate use any of the name brand "Synchromesh" fluids. Castrol Synchromesh is a good option.
Do not use any EP rated gear oil. It does not work well in the X1/9's transmission and there are no hypoid gears to require it.
I see you have installed a limited slip differential. If this is a clutch type you might want to include an ounce of friction modifier.
Do not use any EP rated gear oil. It does not work well in the X1/9's transmission and there are no hypoid gears to require it.
I see you have installed a limited slip differential. If this is a clutch type you might want to include an ounce of friction modifier.
Fiataccompli
Chris Granju
as a point of clarification, would that be "MTL" or "MT85" or MT90" interchangeably?...I've heard "MTL" (which I guess if named similarly would have been "MT80") & "MT90" recommended. I'm not arguing or inviting a debate (I think the search feature can provide that, right?), but as a late (like 20+ years) adopter of modern gear oils, I don't know which i would be best to reach for in a southeastern climate for my two X1/9s that are currently running GL1 ...Hell, come to think of it, I HOPE the '85 is running GL1, but I know the '79 is and always has. Thanks for the space here.
Steve Hoelscher
True Classic
MTL is the stuff you want. https://www.redlineoil.com/gear-oil-for-manual-transmissions
I have had great success with MTL. Been using it since the mid 90s. It works great in the hot southeast climate in both my street car and my autocross car. I do recommend MT-90 for racing applications where higher gearbox temperatures are common. Higher than you would ever see in a street car.
And, a note from the MTL product spec page on the Redline website: Recommended for GL-1, GL-3 and GL-4 applications as well as where most special synchromesh fluids are specified
Fiataccompli
Chris Granju
clarified! many thanks
Paul Valente
Automotive Engineer
The Redline has been pretty well documented to work in the X1/9 transmission and is a good choice. If you can get the added protection of a synthetic GL-4 and it isn't detrimental to the shift quality then why not? It's not very expensive and easily to get in this country.
That is my opinion which I'm entitled to just because everyone with a keyboard is entitled to one.
I also think I'm qualified to chime-in on the science of the subject having spent quite a few years (29 to be exact) on the engineering side of the automotive industry with a particular focus on designing drive-line components. Not trying to ruffle feathers, just laying it out there for your reference...
Redline MTL is a synthetic GL-4. GL-4s do generally have some amount of EP additives in them, though probably less than half what a GL-5 would have. GL-4 was designed for spiral bevels and GL-5 for hypoids, which are spiral bevel gears in which the centerlines of the mating gears do not intersect.* There is no classification that is older than the other. GL-1, GL-4 and GL-5 are all the same age so you can't really credibly state that GL-4 is modern and GL-1 is old. It wasn't like GL-4 obsoleted GL-1. They were designed for different things. There is synthetic GL-1 (if you look hard enough) but it still won't have EP additives in it so it will rely solely on its ability to build a lube film whereas the oils with EP additives form a semi-solid like layer to prevent metal-to-metal contact during extreme pressure events....which is also a mechanism that can screw-up the effectiveness of synchronizers in some cases and lead to clashing/damage/etc.
The only GL classification that expressly forbids all EP additives (and friction modifiers) is GL-1.
GL-1 has fallen into disuse by manufacturers mainly because gearboxes have gotten more power dense and pressures have increased for both bearings and teeth. By modern transmission standards, GL-1 is simply inadequate for a the job basically because they need the EP additives now even in non-hypoid arrangements, but that doesn't mean it isn't adequate for a transmission that was designed to use it.
From the www:
*Just for fun, GL-2, which is no longer active, was for worm gears.
Source:
http://www.api.org/~/media/Files/Ce...blications/1560-Eighth-Edition-April-2013.pdf
http://www.machinerylubrication.com/Read/28470/role-of-extreme-pressure-additives-in-gear-oil-
https://www.redlineoil.com/mtl-75w80-gl-4-gear-oil
http://www.machinerylubrication.com/Read/30366/gear-oil-applications
That is my opinion which I'm entitled to just because everyone with a keyboard is entitled to one.
I also think I'm qualified to chime-in on the science of the subject having spent quite a few years (29 to be exact) on the engineering side of the automotive industry with a particular focus on designing drive-line components. Not trying to ruffle feathers, just laying it out there for your reference...
Redline MTL is a synthetic GL-4. GL-4s do generally have some amount of EP additives in them, though probably less than half what a GL-5 would have. GL-4 was designed for spiral bevels and GL-5 for hypoids, which are spiral bevel gears in which the centerlines of the mating gears do not intersect.* There is no classification that is older than the other. GL-1, GL-4 and GL-5 are all the same age so you can't really credibly state that GL-4 is modern and GL-1 is old. It wasn't like GL-4 obsoleted GL-1. They were designed for different things. There is synthetic GL-1 (if you look hard enough) but it still won't have EP additives in it so it will rely solely on its ability to build a lube film whereas the oils with EP additives form a semi-solid like layer to prevent metal-to-metal contact during extreme pressure events....which is also a mechanism that can screw-up the effectiveness of synchronizers in some cases and lead to clashing/damage/etc.
The only GL classification that expressly forbids all EP additives (and friction modifiers) is GL-1.
GL-1 has fallen into disuse by manufacturers mainly because gearboxes have gotten more power dense and pressures have increased for both bearings and teeth. By modern transmission standards, GL-1 is simply inadequate for a the job basically because they need the EP additives now even in non-hypoid arrangements, but that doesn't mean it isn't adequate for a transmission that was designed to use it.
From the www:
GL-1
Status: Inactive
The designation API GL-1 denotes lubricants intended for manual transmissions operating under such mild conditions that straight petroleum or refined petroleum oil may be used satisfactorily. Oxidation and rust inhibitors, defoamers, and pour depressants may be added to improve the characteristics of these lubricants. Friction modifiers and extreme pressure additives shall not be used.
GL-4
Status: Active
The designation API GL-4 denotes lubricants intended for axles with spiral bevel gears operating under moderate to severe conditions of speed and load or axles with hypoid (see note) gears operating under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications where MT-1 lubricants are unsuitable. The manufacturer's specific lubricant quality recommendations should be followed.
Status: Inactive
The designation API GL-1 denotes lubricants intended for manual transmissions operating under such mild conditions that straight petroleum or refined petroleum oil may be used satisfactorily. Oxidation and rust inhibitors, defoamers, and pour depressants may be added to improve the characteristics of these lubricants. Friction modifiers and extreme pressure additives shall not be used.
GL-4
Status: Active
The designation API GL-4 denotes lubricants intended for axles with spiral bevel gears operating under moderate to severe conditions of speed and load or axles with hypoid (see note) gears operating under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications where MT-1 lubricants are unsuitable. The manufacturer's specific lubricant quality recommendations should be followed.
*Just for fun, GL-2, which is no longer active, was for worm gears.
Source:
http://www.api.org/~/media/Files/Ce...blications/1560-Eighth-Edition-April-2013.pdf
http://www.machinerylubrication.com/Read/28470/role-of-extreme-pressure-additives-in-gear-oil-
https://www.redlineoil.com/mtl-75w80-gl-4-gear-oil
http://www.machinerylubrication.com/Read/30366/gear-oil-applications
Steve Hoelscher
True Classic
Paul,
You are of course correct and I respect your wealth of knowledge on the subject. To be clear, it was never my intent to infer that GL-1 was obsolete and that a GL-4 (or in this case Redline MTL) superseded it. It was my intention to note that traditional Petroleum GL-1 has been surpassed in performance by modern, synthetic, synchromesh formulated gear oils like MTL.
Thanks for clarifying the GL classifications.
Dr.Jeff
True Classic
So I assume this is a 4-speed? Not that it matters regarding lubricants, just confirming there isn't a new LSD for the 5-speed.
Dmitriy
Low Mileage
I'm very sorry that I misled you. This is a photo from the Internet as an example. My gearbox is 5 speed. Without LSD. She's already on the car. I used a gearbox from Fiat RITMO as a spare part for my gearbox.
Paul Valente
Automotive Engineer
Dobre utra, Dimitri. You might want to try an agricultural tractor dealer for GL-1 if you want to use that. If you can't get Redline MTL, there are lots of cars that use GL-4. As I pointed out, these oils don't have to follow a set formula to earn their API classification. We have very few Russian posters and your oils may be composed of different base-stocks and additives than ours so keep an eye on it for a while for any signs of gear clashing.
Good luck!
Good luck!
Paul Valente
Automotive Engineer
In looking back on it, I guess I didn't point out that the classifications are not based on a set formula. They are performance based. In other words, to call an oil a GL-5 or ATF or whatever, it has to pass a certain set of tests. This is why you can see fluids like ATF that are rated for multiple classifications like Dexron AND Mercon. Basically there is a base-stock* (80% maybe?) and then a bunch of additives they put in to make it into motor oil, ATF, GL-4, etc. Ironically, times the additives are slaughter house derived (I know, gross right?) so the idea of aftermarket "snake oil" additives is not ridiculous. It already (figuratively) has snake oil in it.
* there is some controversy over what constitutes a synthetic, semi synthetic or mineral oil base-stock. Different countries have different definitions. In this country, you can start with something that comes out of the ground and refine it enough to call it synthetic.
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* there is some controversy over what constitutes a synthetic, semi synthetic or mineral oil base-stock. Different countries have different definitions. In this country, you can start with something that comes out of the ground and refine it enough to call it synthetic.
Dr.Jeff
True Classic
I found similar info about the regulations on what constitutes synthetic, etc, from different countries. Pretty interesting when you consider there is a large market of lubricants from other countries that specialize in various motor sports. But in general it appeared to me that many of the other countries had much stricter regulations than the US does.
The whole subject of additives and the aftermarket products has always been interesting. Just on a superficial level, it seems to me (subjectively) that the particular mix of additives put into a particular product could be adversely affected by randomly adding some other product into it. In other words, are all additives compatible and is more necessarily better?
Perhaps off topic a little, but I wonder about coolants (antifreeze) in the same light. For example there are several different types specified for various vehicles. Then there are the "universal" ones that claim to be good for all vehicles. Seems a bit contradictory.
The whole subject of additives and the aftermarket products has always been interesting. Just on a superficial level, it seems to me (subjectively) that the particular mix of additives put into a particular product could be adversely affected by randomly adding some other product into it. In other words, are all additives compatible and is more necessarily better?
Perhaps off topic a little, but I wonder about coolants (antifreeze) in the same light. For example there are several different types specified for various vehicles. Then there are the "universal" ones that claim to be good for all vehicles. Seems a bit contradictory.