Torsen vs standard Traction lok LSD differential pros and cons?

[Shifting_Gears]

Torsen is superior in everything except straight line traction. It will fight for traction more than a clutch style LSD. With a traditional LSD once the clutches engage you get a locked differential until there is no more variance in wheel speed, the the clutches no longer force the axles to turn at the same speed.

As mentioned, the Torsen can exhibit the characteristic of “hunting” for which wheel to lock during hard, straight line acceleration where traction is limited at both wheels.

However - I would venture to say there’s very little performance difference between the trac loc LSD and Torsen in actual drag times.

The trac loc is tried and proven, but it is a wear item. Eventually you’ll get one wheel peel and the more you excercise the diff with acceleration under hard cornering (IE; road course or autocross), the faster it will wear. Spider gears can also wear. It’s truly not HARD to rebuild, but you have to pull the LSD and ring gear assembly from the axle. You can also upgrade the clutches.

I LOVE LOVE LOVE the Torsen in my GT and wouldn’t EVER desire another trac lok over it. It transforms the car’s ability to put power down in a corner with out drama.

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[Andy13186]

After 25k miles I've Been very satisfied with my torsen, and I did have a clutch style go out on my in my 2003 GT, had to have it repaired to get back to 2 wheel burnouts back in like 2010.

With this torsen I've been able to keep both wheels spinning to like 70 mph through 1st 2nd and 3rd gear in drag mode with advancetrac still on and it stays straight enough to not kick in. Sometimes can keep them spinning into 4th if its cool weather. Pretty fun. With drag radials it just hooks even on the street. I am not noticing the back and forth traction hunt at all anymore from the torsen if I break them loose hard enough it just keeps both spinning perfectly and the car can stay straight.

 

[Brian@BMVK]

Torsen is superior in everything except straight line traction. It will fight for traction more than a clutch style LSD. With a traditional LSD once the clutches engage you get a locked differential until there is no more variance in wheel speed, the the clutches no longer force the axles to turn at the same speed.

As mentioned, the Torsen can exhibit the characteristic of “hunting” for which wheel to lock during hard, straight line acceleration where traction is limited at both wheels.

However - I would venture to say there’s very little performance difference between the trac loc LSD and Torsen in actual drag times.

The trac loc is tried and proven, but it is a wear item. Eventually you’ll get one wheel peel and the more you excercise the diff with acceleration under hard cornering (IE; road course or autocross), the faster it will wear. Spider gears can also wear. It’s truly not HARD to rebuild, but you have to pull the LSD and ring gear assembly from the axle. You can also upgrade the clutches.

I LOVE LOVE LOVE the Torsen in my GT and wouldn’t EVER desire another trac lok over it. It transforms the car’s ability to put power down in a corner with out drama.

The torsen doesn't 'lock' at all, and neither does the clutch pack. The standard limited slip is an open diff with clutches on the outputs that minimize relative wheel speeds beyond what the open diff would allow for. It has very low torque bias ratio and its better for straight line use because it can provide good forward thrust even when one tire is lightly loaded. The torsen requires the inside tire to be loaded to bias torque to the outside, and with its high torque bias ratio, is why it is so important to focus on making the diff work when setting up the car.

 

[MRGTX]

I just swapped out my Tracklock from my base car with just 3k miles on it. I’m happy to sell it for cheap along with or separate from the 3.55 ring and pinion. Drop me a PM.

 

[K4fxd]

I come from the days when the "Detroit locker" was king of the hill. Still have a soft spot for the ratchet but smooth it is not. You won't ever break it either.

The locker was quicker on restarts but the open was most times quicker in the corners.

I don't know why but I am unable to quote people.

I do agree with whoever said the open diff with proper "advance track" technology is the superior way to apply power.

 

[Elp_jc]

I've never had a Torsen before, and it feels awesome in the twisties. Will never drag-race, which is reportedly its only (minor) disadvantage, so happy to have it .

 

[Vlad Soare]

What kind of maintenance does the clutch-type diff need? With all the friction happening inside, I imagine it must have an oil filter and a tight schedule for replacing both the oil and the filter. I can't seem to find any mention of this in the manual, nor in the service guide.
Also, how do you know when it's time to replace the clutches? Are there any signs that they're starting to die? Is their demise gradual, meaning that the diff will lock less and less as time goes by? Or will the diff work normally one day, and then turn into a fully open one the next day?

 

[gadgtfreek]

Not sure how I missed this thread when I bought mine a few months ago, but very good detail about the Torsen. I was unfamiliar to it, but after reading this "I get it" and why it does what it does sometimes. Very informative thread.

 

[WildHorse]

What kind of maintenance does the clutch-type diff need? With all the friction happening inside, I imagine it must have an oil filter and a tight schedule for replacing both the oil and the filter. I can't seem to find any mention of this in the manual, nor in the service guide.

There is no oil filter. Clutches are carbon fiber, there's also a load 's' spring in there. It's a very strong design.

 

[Vlad Soare]

I thought those clutches must produce dust, which will accumulate in the oil, hence my idea of a filter. But I must confess I don't really know how these diffs work internally. I know what they do, but not exactly how they do it.
But like all clutches, these will eventually wear out. Is there a prescribed number of miles for their replacement? Or any way of knowing when they're on their last legs? Do they give any signs before dying completely? Are they a replacement item, or will the entire diff need to be changed?

 

[K4fxd]

They sell replacement clutches.

I don't know the service life.

 

[Shifting_Gears]

I thought those clutches must produce dust, which will accumulate in the oil, hence my idea of a filter. But I must confess I don't really know how these diffs work internally. I know what they do, but not exactly how they do it.
But like all clutches, these will eventually wear out. Is there a prescribed number of miles for their replacement? Or any way of knowing when they're on their last legs? Do they give any signs before dying completely? Are they a replacement item, or will the entire diff need to be changed?

They spend their life submerged in gear oil, so no room for dust the clutch material does wear though and that’s part of the reason there’s service intervals for the fluid. There’s also an additive “friction modifier” that helps control the level of “slip” between the clutch packs to keep them from locking up too soon and causing a bind in the rear wheels (due to difference in wheel speed when turning sharp at lower speeds).

Short explanation, the differential consists of 4 spider gears, clutch and friction disks, an S-clip and center pin to center the upper and lower spider gears. The axle shafts keep the side spider gears centered. During straight line acceleration, the wheels spin the same speed. During a turn or when one wheel loses traction, wheel speed increases compared to the other. When this happens, the spider gears turn and friction builds in the clutches and it keeps the wheel with the least traction from receiving all of the power and continuing to spin.

The differentials are fairly robust so without heavy cornering and low traction situations (thinks donuts, autocross) they should easily last 100k or more.

The clutches are a serviceable item so you can rebuild them without having to replace the entire differential. The spider gears also wear so it’s important to ensure they aren’t chipped and still fit tightly. However these will normally last the service life of the differential.

The only real sign the clutches are worn is one wheel peel when you lose traction.

 

[Performance nut]

So I have had both in my 2018. Came with the 3.15 traction loc and I just swapped to a 3.73 Torsen. The differences in a straight line are pretty minimal. In the turns, it is much more noticeable, especially from a stop/slow speed where you accelerate. Better control, better grip.

Only odd thing I have noticed is a low speed noise from the rear. I swear it sounds like rubbing but nothing is rubbing. It only happens when I'm turning, forward or backwards. At speed either it doesn't exist or my exhaust drowns it out.

 

[Brazos609]

I come from the days when the "Detroit locker" was king of the hill. Still have a soft spot for the ratchet but smooth it is not. You won't ever break it either.

I can't believe it when I read posts with people complaining about a Torsen clicking. I think mine is almost invisible. Making a turn that has an elevation change, like into or out of a steep driveway to road transition, is the only time I can feel a slip as a tire catches up. If they heard the clank-clank-clank all the way through every turn that a true locker does they would probably faint. A true locker make you check your mirrors all the time to make sure you didn't snap an axle because it sure sounds like you did.

 

[gadgtfreek]

The only time I notice is as you say, going in and out of areas with a steep incline/at an angle. I love how it handles, and some reading here explained it to me (first time with a LS rear end).

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