80W-140 and Torsen Biasing

[Soma07]

quote:

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Originally posted by metroplex:
How are the Torsen differentials holding up in the F-bodies that are driven hard?

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I'm not much of a drag racer but as far as I can tell they hold up about as well as the Auburn clutch style differentials used 93-98. But of course that isnt saying much since the rear end (usually the pinion gear) is the first thing to go on these cars when you start launching hard with sticky tires. Most guys who are really into draging swap in a 12bolt axle ASAP since its much stronger than the stock 10bolt no matter what differential you put in it.

On the other hand when it comes to autocrossing a Torsen is the differential to have if you're serious. Specifically the T2R due to its higher bias ratio.

 

[Michael SR]

quote:

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Originally posted by metroplex:

How are the Torsen differentials holding up in the F-bodies that are driven hard?

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horribly. ditto the auburns. in my '92 that i auto-x, i put the $99 stock LS1 torsens from SLP. they'll last maybe a year, usually less, before i start spinning the inside rear out of turns.

the real problem is that neither of those is rebuildable. the clutch-type limited slips in mustangs, you rebuild them once with a different plate order, and then as it wears you just put in thicker shims to compensate. it's lifetime setup like that.

i've heard the T2R lasts longer, but i'm not going to find out how much longer at $500+.

-michael

 

[metroplex]

Interesting - the Torsen differential doesn't use clutches like the auburn or the Spicer Traction-Lok. I know the Torsen tends to act like an open more readily than the clutch type which have better lockup.

I heard the Auburns aren't rebuildable - you have to send them back to Auburn for them to repair in case you burn up the clutches?

 

[MolaKule]

I realize the topic is about Torsens, but I have an Auburn in the '86 Burb
2X2 and its still working and it never shudders. Of course, the Burb never sees any "Meets" either.

 

[RobZ71LM7]

Funny you say Torsen's don't last in autocross. I talked to Sam Strano (F-stock and ESP nat'l champ) and he said he burned up auburns fast as hell even some special one which I forget the name of. He says he's had no problems with Torsen's-he just runs heavy fluid on non T2R's.

 

[metroplex]

Using a heavy fluid like 80W-140 or 75W-140 in a Torsen will help increase lockup performance somewhat. Use synthetic tho!

 

[sprintman]

nick778 you can get the Redline FM seperately and 'tune' an LSD with it. Their web site has good info. I use RL 75W90 in my Outback rear and 75W90NS in g'box. Good stuff IMO.

 

[VaderSS]

Not all T2Rs have clutches. The ones for the Impala SS do not. They rely strictly on the pre-loading.

I had noticed this post and inquired to Torsen about thicker oil. Here was there answer;

quote:

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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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[Judd]

Just some info on the Gov-Locs. The Gov-loc is a hybrid design, it has clutches and a automatic "locker". Once the clutches slip and one wheel spins a few times, the automatic locker will engage and lock-up the rear.

It's a pretty good design but it's a bit weak in smaller axles. Abuse a Chevy 10 Bolt with a Gov-Loc and it will break. On the other hand, I've never seen a 14 Bolt Gov-Loc break.

The one in my 14Bolt has almost completly worn out clutches but once the tires spins a bit-the axle locks right up. I can have one wheel completly off the ground and still have traction. Mine is getting a bit old so once it locks up, it stays that way at least untill I reverse for some reason. Inside tire chirps on tight corners.

Since it does have clutches, a new one will need some friction modifier to keep shudder down in tight corners. This to the best of my knowlege. Little disclaimer there.

Mine is worn out so I don't have to worry about clutch shudder.

BTW, I've had both the Torsen and a Auburn LSD in my Firebird. I liked the Torsen better. Heavy oil {I use 85W140 also, hey it's a 7.5 inch ring gear-it makes me at least "feel" better!} did not seem to improve the bias a noticable amount in either LSD.

 

[metroplex]

TractTech (makers of TrueTrac) and Torsen told me to use whatever the manufacturers recommended and that using synthetic would hurt torque biasing!!

Now what is the principle difference between what hte car manuf recommends and synthetic gear oil?

Viscosity, am I correct?

Dino 80W-90 is thicker when cold compared to synthetic 80W-90 or 75W-90.

Regardless, I use synthetic 75W-90 w/ my TrueTrac (same thing as a Torsen T-2 with different helical worm gears).

 

[VaderSS]

I wonder how the diff would do with a thinner oil such as Redline's MTL 70W80, Lightweight 75W80, or Superlightweight 70W75(ATF vis)

I know the Torsen would take it fine, but what about the ring and pinion and bearings, both diff and wheel?

[ May 28, 2003, 03:01 PM: Message edited by: VaderSS ]

 

[metroplex]

I'd say that under light loads - probably nothing. But when subjected to heavier loads (racing, towing, etc...) you might burn out the bearing cones.

 

[Dominic]

For what its worth, the well regarded Sam Strano of www.stranoparts.com runs and prefers the Heavyweight Shockproof Redline Gear oil on all torsens without clutch packs. He even claims it helps the biasing on them, its down the page a ways on the front page... do a ctrl-F search for "shockproof" and you'll find it.

 

[VaderSS]

I e-mailed both Redline about the above oils, and Strano about that theory, which is contradicted by the maker of the Torsen.

I've not received replys. I think I'll go with Redline 75W90 NS, which does not contain friction modifiers.

 

[VaderSS]

They responded. Think I'll go with the NS...

quote:

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I have a daily driven 1996 Impala SS with a Torsen differential.
Torsen states that it is ok to run the Torsen ATF viscosity oil for
higher biasing, but I wonder if it would be ok, long-term for the
ring and pinion, and the axle bearings in my 8.5" 10 bolt rear end.

The car is daily driven, has about 300 HP, 370 Lb-ft, weighs
about 5000Lbs fully loaded, very rarely(twice a year or 800
miles) tows a 3000Lb trailer.

I was considering your MTL 70W80, LightWeight Gear Oil or Superlight
Gear Oil .

If this is not recommended, what about the MT-90 or 75W90 NS which
are in the recomended viscosity range, but is not as slippery as
your other gear lubes?

Regards,
Wayne Bengston
Houston, TX


Torsen must be referring to use in a front wheel drive differential,
I definitely wouldn't recommend using an ATF in a rear hypoid
differential.

In your differential I would recommend the Red Line 75W90, it
satisfies the viscosity and GL requirements of the differential. The
75W90NS could be used but the friction modifier in the 75W90 helps
reducing friction and temperatures.

Regards, Dave
Red Line Oil

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quote:

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Other Info: I was told recently that heavier oil would help the biasing in
my Torsen T2, I was told that this site advocates that.

I emailed Torsen and was told that the Torsen works via friction and thrust
forces, and that the thinner the oil, the higher my bias would be. I was
informed that the higest bias was to be achieved using ATF, but to use what
was reccomended by the owners manual for my car.

I was told that using thicker oil actually reduces the bias by keeping the
parts inside the Torsen further apart.
Wayne Bengston


Thinner oil has less friction. We run Heavy Shockproof, and we have less inside wheelspin because of it, the diff works better when thicker fluid (ever notice it's better when the temperature is low?).


Sam Strano Jr.
Strano Performance Parts
www.stranoparts.com
800-729-1831 orders/price info.
814-849-3450 technical info.

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[metroplex]

Keep in mind: with a torsen differential, you want to reduce friction - the friction modifiers found in the 75W-90 Redline would help reduce friction and would ultimately only serve to prolong the life of a Torsen/TrueTrac. The helical worm gears basically ram against the body of the differential - according to the manuf, there isn't much friction involved here but then again all those metal chunks from breaking in the Torsen MUST have come from somewhere.

If I were you, I'd run the 75W-90 Redline instead of the 75W-90NS, just look at the specs for each. The 75W-90NS is definitely a lighter gear oil than the 75W-90 - the difference isn't just in the addition of the friction modifier for the regular 75W-90.

But then again it may very well run fine on 75W-90NS. I just know that the Torsen/TrueTrac needs all the friction reduction you can give it because it doesn't use clutches and relies on the helical worm gears. I definitely found a LOT more metal in 250 miles of breaking in a Torsen than in 500 miles of breaking in a new Ford Traction-Lok.

 

[Dominic]

I'm currently running 75W-90 Valvoline synthetic in mine, I'll be trying the heavy shockproof soon.

 

[metroplex]

I used to use Valvoline Synpower 75W-90 and found that it foams too easily. When I went to drain my Ford 7.5, there were air bubbles all over the ring gear, spider gears, and side gears.

Pennzoil doesn't seem to foam as easily.

 

[VaderSS]

Torsens have a lifetime warranty. Torsen does not require friction modifier with conventional oils so I don't think that a synth needs it either.