Non-FrictionModifier Synthetic Gear Lubes

[VaderSS]

I'm running a Torsen T2, so I don't need FM.

I'm looking at non-FM 75W90 GL-5 synthetic gear lubes.

So far I've come up with;

Redline 75W90NS

Neo 75W90 EP

Redline Specs ?

Neo specs
Specific Gravity 15.6°C (60°F) 0.87
Flash Point 246°C (475°F)
Viscosity @ 100°C cST (SUS) 15.4
Brookfield vis., - 40°C 48.500
Pour Point - 45
Viscosity Index 180
7 Day Moisture Corrosion (L-33) Pass
API GL-5 Test Sequence Pass
Mil-L-2105 C Test Sequence Pass

Thoughts?
Any other non-fm synths out there?

I am currently running Mobil 1 75W90 because it is available OTS.

M1 specs;
Product Number 51130-3
SAE Number 75W-90
Gravity, API 27.0
Flash Point, ASTM D 92, °C (°F), min 175 (347)
Pour Point, °C (°F), max -46 (-50)
Viscosity
cSt at 40°C
cSt at 100°C
cP at -40°C (-40°F) 106
15.2
130,000
Viscosity Index 150

 

[MolaKule]

How about Pennzoil Full Synthetic?

This is a PAO/Ester GL-5.

 

[VaderSS]

I can't get the Pennzoil site to come up. It has no FM added? I know that most of the synths do.

 

[metroplex]

what's wrong with FM in a Torsen?

I have a Detroit TrueTrac (more durable Torsen T-2) in a Ford 8.8 rear end, and I'm using Redline 75W-90

The FM would just decrease friction. In a helical gear limited slip, that's what you want to do!!!!!! The less friction the less metal wear.

 

[Greaser]

I use the Pennzoil 75W-140 syn lube in the rear of my Jeep's Dana 44 with the limited slip (trac-loc,clutch packs)...the Pennzoil lube says it has the friction modifier allready added ,but I put in a bottle anyway just to be sure...both rear tires will light up if I want them to so they are working fine.My friend has the new Jeep Rubicon with the torsen type limitd slip out back..I did a drain and fill on his axles using the same Pennzoil lube,same weight...but didn't put in the friction modifier...we put it thru the paces last week-end...mud,rocks,steep approach angles...everything worked like a charm

 

[Pablo]

I'm with metroplex, I don't get it.

What harm would using a gear oil such as the Amsoil Series 2000 75W-90/140 do?

 

[joee12]

quote:

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Originally posted by Pablo:
I'm with metroplex, I don't get it.

What harm would using a gear oil such as the Amsoil Series 2000 75W-90/140 do?

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That makes three of us. Good discussion and post, but I just don't see the harm in running the FM in your Impala's rear-end. Joe

 

[VaderSS]

quote:

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The FM would just decrease friction

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Exactly!

From a Torsen support tech;

quote:

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The Torsen works because of friction and thrust forces.

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Basically, you want the lowest viscosity oil that meets the OEM specs and free of FM. In my case that is a GL-5 75W90. The Torsen is happy to run in ATF, and will get it's highest bias in that lightweight oil.

[ June 25, 2003, 08:28 PM: Message edited by: VaderSS ]

 

[MolaKule]

If the Torsen has no clutches (and I believe that's why they invented it) I see no reason why any good synthetic 75W90 wouldn't work, added FM or no FM. Besides, the esters in a Full Synthetic are what provides most of the FM anyway.

The thinner the oil the less Hp used in heating the oil, but for a diffy that uses only the gearing and reaction forces for traction, I would use the best shear-stable GL-5 available.

[ June 26, 2003, 01:36 PM: Message edited by: MolaKule ]

 

[VaderSS]

quote:

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If the Torsen has no clutches

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The T2 does not. It was actually designed to be run in ATF. Anything thicker reduces the biasing so basically, you run what the non-limited slip diff calls for. I'm not really that concerned with the Torsen part of the diff, since it's actualy running in more protection than it was designed for, and I've seen plenty of ring and pinions last forever on conventionals and NO oil changes, so with the annual one this one sees and the fact that I'm running a high grade synth, it should be fine.

The Pennzoil synthetic looks about the same as the Mobil 1 in the specs. The Pennzoil Super EW looks very solid though, but a 35 Lb pail is the smallest size...

I'll go with the NEO, most likely. I plan on running the M1 for about 6 month and we'll see how it does.

[ June 26, 2003, 05:26 PM: Message edited by: VaderSS ]

 

[Greaser]

quote:

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Originally posted by MolaKule:
If the Torsen has no clutches (and I believe that's why they invented it) I see no reason why any good synthetic 75W90 wouldn't work, added FM or no FM. Besides, the esters in a Full Synthetic are what provides most of the FM anyway.

The thinner the oil the less Hp used in heating the oil, but for a diffy that uses only the gearing and reaction forces for traction, I would use the best shear-stable GL-5 available.

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When I went to do the new Jeeps' axle ,it had a tag on it stating "75W-140 SYN"...so thats what I put in...I was going to go with a 75W-90 SYN but better sure than sorry with a new vehicle..especially if Dana put a tag on the thing with a specific weight and lube.

 

[metroplex]

quote:

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From a Torsen support tech;

quote:

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The Torsen works because of friction and thrust forces.

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Basically, you want the lowest viscosity oil that meets the OEM specs and free of FM. In my case that is a GL-5 75W90. The Torsen is happy to run in ATF, and will get it's highest bias in that lightweight oil.

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You misunderstood what they were saying then - its working because of friction and thrust forces but that doesn't mean "reduce the friction and the Torsen no longer works"

You reduce the friction and REDUCE THE WEAR. Ever open up the rear end in your torsen to see the gear oil? I found lots more metal initially than in breaking in a traditional Traction-Lok/clutch posi.

The helical gears slam against the differential case in the Torsen. The FM would just help prevent excessive wear due to reduction in friction.

Most ATFs have friction modifier additives in them - so if the Torsens were designed for use in ATF, then there you go - using a gear lube w/ FM isn't going to destroy the unit any more than using a gear lube w/o FM.

I'm using Redline 75W-90 in my Detroit TrueTrac w/ great results.

[ June 27, 2003, 02:36 PM: Message edited by: metroplex ]

 

[VaderSS]

Here is the e-mail about the lighter weight. They have not replied to my e-mail about FMs yet.

quote:

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-----Original Message-----
Sent: Monday, May 26, 2003 1:13 AM
To: [email protected]
Subject: Gear oil wieght


I've been told that running a thicker oil, such as 80W140 will result in higer biasing with my Torsen T2.

Is this true?

Thanks,
Wayne Bengston
1996 Impala SS


Just the opposite! You will see a decrease in bias because the thick film will keep the internal parts apart. The Torsen works because of friction and thrust forces. The drop is noticeable if you go from ATF to an 80W140, around 0.6:1 whereas if you went from an 80W90 to 80W140, the drop is around 0.2:1.

Thanks for the question and interest in Torsen.


Sent: Tuesday, May 27, 2003 5:01 PM
To: [email protected]
Subject: Re: Gear oil wieght


Since the recommended oil is 80W90 gear oil in my 96 Impala's differential, that would be the best one to run. Is that correct?

Yes, we always recommend that the driver follow the vehicle's owners manual for lube specifications!

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This is from the FAQ;

quote:

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Is it true that the Torsen unit in the production Camaro needs the GM modifier added?

GM issued a technical bulletin adding modifier to the rear axle oil. This was done to quiet what we call a "Rusty Screw" noise that we heard in a very small percentage of vehicles. This does not happen in all cases, however to address owner's concerns we asked that the modifier be used in all instances to insure that the driver would not get this noise. When replacing the fluid it is at the owner's discretion whether or not to add the modifier. Elimination of the modifier does not affect durability of the differential.

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So from what I understand, FM is not needed. It might be needed in some cases to eliminate the noise, but it's not a durability issue.

[ June 27, 2003, 04:01 PM: Message edited by: VaderSS ]

 

[metroplex]

VaderSS: a few folks who installed TrueTracs (beefier T-2s) noticed a weird noise for the first 500 miles.

If the backlash is properly adjusted you should not hear any weird noises. I didn't hear anything after the first 3 miles - at first there was a lot of grinding and nashing but then poof - it was smooth as an open differential.

If you look at how the Torsen works, you will see that reducing friction is a good thing. If you don't add FM nothing bad will happen, but I would rather go with a synthetic right now instead of looking around for a non-FM added synthetic gear lube. Either way it would be fine, but I would prefer slightly less friction to prolong the life of the casing and gears.

TracTech told me to use OEM dino 80W-90, as "synthetic oil would hurt biasing" - so go figure.

 

[VaderSS]

quote:

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but I would rather go with a synthetic right now instead of looking around for a non-FM added synthetic gear lube.

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As I said above, I have Mobil 1, which has FM added, in it now, because it was easily available. Even there was no such thing as a non-FM synth, I'd still run synth.

 

[MolaKule]

Just a clarification:

quote:

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You reduce the friction and REDUCE THE WEAR. Ever open up the rear end in your torsen to see the gear oil? I found lots more metal initially than in breaking in a traditional Traction-Lok/clutch posi.

The helical gears slam against the differential case in the Torsen. The FM would just help prevent excessive wear due to reduction in friction.

Most ATFs have friction modifier additives in them - so if the Torsens were designed for use in ATF, then there you go - using a gear lube w/ FM isn't going to destroy the unit any more than using a gear lube w/o FM.

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The main reason for Friction Modifiers is to reduce the coefficient of friction between mating surfaces and to reduce the "viscous friction" between the layers of oil. Friction modifiers are usually added to Gear Lubes to ensure smooth clutch pack or cone engagement for Limited Slip or positraction differentials. In these differentials, shudder is caused by a phenomenon known as "stick-slip." FM's reduce or eliminate this stick-slip and ensure a smooth transition from full slip to full engagement.

While FM's reduce wear somewhat, its the Anti-Wear/EP additives that reduce the metal wear on gear teeth and bearings.

So FM's shouldn't really matter too much for the Torsen design. It appears the Torsen design is more sensitive to lube viscosity than to whether or not FM's are in the GL.