LS Differential fluid in a Torsen Differrential?

[ChristianReske]

I am puzzled.
My car has a Torsen differential. This has some "Clutch Discs" ("Washers") and relies partly on friction for proper function. See attached pages from the Workshoip manual.
The owner manual only says "Use SAE 90 GL 5 Oil", no mention of LS Fluid.

Is it safe to use LS diff fluid in this type of differential or could this cause problems (To much fricton, harming the waschers, shearing the holding tabs of....) ?

 

[Colt45ws]

Its doesnt use any clutch frictions. All the friction is in the planetaries against the case of the unit.. What I have heard is that LS additive may reduce the bias ratio of the unit, which is a measure of how well it works. LS additive, which is Friction Modifier does not increase friction, it reduces it. so the gears slip easier.
I would try to find a gear oil that does not contain LS additive for maximum performance of the unit, but I do not believe it will cause any long term harm or damage if it is used; just a loss of its capabilty for as long as the LS additive remains in the case.

 

[ctechbob]

https://torsen.com/lubricant-part-1/

https://torsen.com/lubricant-part-2/

"In truth, a Torsen differential typically isn't that fussy about which lubricant you choose - within reason. A Type-2 or T-2R model will operate in really any common lubricant, ranging from ATF to heavy weight gear oil. On the other hand, if you happen to be using a Type-1 differential, you need to a little more choosy. The crossed-axis gear mesh of Invexâ„¢ gearing requires the use of oil with high-pressure additives. This means they need gear oil with a GL-5 rating. But even that isn't too difficult. Hypoid ring & pinion gears have the same need, so almost all normal axle lubricants are up to the challenge. But be sure to look for the rating on the bottle anyway."


For a torsen, unless you're tuning for maximum performance, it doesn't really matter. As they say in the article, use the oil that makes the ring and pinion happy.

 

[Trav]

LS additive is not needed in a Torsen diff. When I built my 4T65E I used a GMPP Torsen diff with 1" chain and it still uses ATF fed by the same diff lube tube as the original diff unit.

 

[zeng]

Originally Posted by ChristianReske
I am puzzled.
My car has a Torsen differential. This has some "Clutch Discs" ("Washers") and relies partly on friction for proper function. See attached pages from the Workshoip manual.
The owner manual only says "Use SAE 90 GL 5 Oil", no mention of LS Fluid.

Is it safe to use LS diff fluid in this type of differential or could this cause problems (To much fricton, harming the waschers, shearing the holding tabs of....) ?


It's safe though LS is not required.
No, it won't.

 

[neo3]

I have a torsen diff also. It's very noisy during turns at moderate speed, say over 40 MPH. This noise is supposed to be common, usually called a "rocks in a box" noise. I've read that using the LS additive may quiet it down, even though it's not supposed to be needed in a Torsen. I currently have Supertech 85W140 in it (which has no LS additive), which I thought would quiet it down (it's supposed to take 75W90), but if anything made the noise slightly worse.

 

[xtell]

I contacted Torsen directly asking about differential fluid for my 1999 Trans Am. I was advised to use 75w-90 synthetic fluid only. In my owners manual it is listed to use a GM friction modifier additive "if needed" to prevent creaking noise when going around corners. I have just used straight 75w-90 synthetic (Pennzoil and Valvoline) and never noticed any creaking sound from my cars differential, thus no need for a friction modifier additive.

 

[DoubleWasp]

posted in the wrong thread

 

[ChristianReske]

Sorry for the late reply, just want to say thank you all!