Thank you for labeling the bolts. I was unsure about that.

Eaton Truetrac are designed for medium duty 2WD and 4WD applications. They work well in the front and rear, and are so smooth that there is little or no hint of resistance in the steering wheel when used in front drive steering axles. Like the Gleason Torsen, the Eaton Truetrac does not bang or clunk, has no clutch chatter, does not wear out like clutch type positractions, does not need limited slip additive, and needs no preload or clearance adjustments.

Just replaced the stock clutch based LSD in my Jeep with this unit. What a difference in traction. Instant lockup, feels like there's a locker back there and it handles the rain with no weird handling. Tested it out by putting one wheel on pavement and the other in dirt and stomped on it. Jeep took off like I was on pavement with nearly no slip on the dirt side wheel. Amazing unit, quiet too.

They use worm wheel gears that work on the same principle as a worm gear. When the unit is loaded, the worm wheels are forced away from each other and against the case. They develop locking torque by the light friction between the worm wheels and the case. This light friction is multiplied by the ratio of the worm wheel which depends on the size of the worm wheel relative to the size of the side gear.

When I had my 01 2wd Yukon with this installed I could drive through most things. Control was superb, would even drive in deep mud. Could get out at idle speeds and both tires would spin in place, hop back in and give throttle. Would push right right out of low traction situations. Also handled the abuse of drifting with ease.

I put one of these in the Suburban we take camping and tow our old bass boat with, I absolutely love it. This differential really helps with GREAT traction in the rain and on slippery boat ramps.

When used in situations like rocky trails where one wheel gets off the ground, the unit will not lock up 100%. Light application of the brakes will help the differential engage more transferring power to the tire that is still on the ground. For extreme situations where the vehicle will have one wheel in the air often a locking differential provides better power transfer to the wheel on the ground.

Just got this installed in my gmt800 after the original diff gave out at 230k. It's only in the rear as my truck is only 2wd, but coupled with 4.10 gears, she hooks up nice and inspires confidence at speed. Even just today in the rain, nice and composed when it needs to be, wild and fun when it wants to be. Well worth it imo.

I had one of these(GM 10 bolt, 8 1/2" 3.23), put in my '79 Buick a few years ago. It works great, I went through some deep friggin' snow/ice over Donner Pass with chains on and it handled well, not scary at all. I'm going to put another one in my kids car, maybe a 3.08 : ) Only thing they say is to keep equal tire pressure/diameter and even wear on the back tires.

This type of differential is designed primarily for street and light Off Road operation. It is not designed for continuously abusive situations such as Drag Racing, Truck Pulling or Rock Climbing. Please let us know if you have any additional questions. Thanks for watching!

Hi xramcam, In a street driven vehicle, about 400-450hp dependably. Thank you for watching!

Yes that’s correct, when a wheel slips it engages. Under normal driving & road conditions, this unit will last the life of the vehicle. It is not designed for huge tires, extreme off road or ultra high horsepower. It is designed mainly as an upgraded replacement for factory limited slip differentials.

The manufacturer can change the amount of torque biasing or lockup by simply changing the diameter of the gears, or the pitch and spiral of the teeth. A larger difference in the size for the worm wheels and side gears (smaller worm wheels and larger side gears) will increase the lockup force. Increasing the pitch and spiral of the teeth will also increase the lockup forces.

Like everything, there is a limit as to how much lockup force is reasonable. Making the unit too "aggressive" will cause tire scrub during everyday driving and will cause the unit to wear out too quickly. All of the feedback that I have received from customers indicates that the unit works very well for mud and snow, while going unnoticed during every day driving.

The music took me back to the 90s when street fighter was poppin

I have a detroit tt in my 95 z28 camaro from moser who built a 12 bolt for me to get rid of the 10 bolt that i had rebuilt for me 3 times. After the 3rd time breaking the 10 bolt i said screw it and paid the 3 grand. All i said was i wanted the latest and greatest and they suggested and True Trac instead of a clutch pack limited slip differential. I love it. It even has a slight hum to let you know it's tough and ready for abuse. The only problem ive had with my 12 bolt is a right side axle seal leak. So i give a Tru Trac a 10 out of 10.

@gasripper2 That is when you press the brakes to get some traction on both wheels. I know it sounds weird but that's what they teach you in the army to do and it works. The explanation is simple when you brake the light wheel slows down and it forces the locked one to go.

had one of these units installed in my 02 silverado z71....best thing money i ever spent on it...well besides my vigilante and trans upgrade haha..honestly though, huge difference, posi burnouts, great handling in inclimate weather, good stuff

I’ve read that these are great for front differential applications in non-hardcore applications. I had Auburns in both ends of an F150, and it would get a little twitchy turning in snow with the hubs locked.

I put one of these in my Jeep and my Bronco. After that, I rarely need to go into 4WD even in snow, sand, mud, etc. at least on level ground. Still need the front wheels for uphill slippery slopes.

From looking at diagrams and pictures of this differential, I have concluded that the torque-biasing works due to the helical nature of the gears. As the input torque increases, the "sun and planetary" gears are forced into the walls of the unit, creating friction and turning the wheel. Whatever wheel has more resistance to movement (taction), therfore receives more horizontal force, resulting in increased friction on the gears, thus the torque bias functions.

just had one fitted to my VE SS best diff ever , smooth , less friction (better fuel economy , more power) and launchs are amazing.

@deezynar it's on the older Hummer and military HUMVEE driving manuals somewhere that if you apply the brakes to the spinning tire, it will force some of the torque to transfer to the other side. This is the same thing a limited slip will do, take some of that wasted torque and transfer it to the tire with more grip by providing a certain amount of built-in "braking" action for each axle that simulates traction.

Only then will the torque transfer occur - when it is needed. As with an open differential, the TrueTrac side (or spider) gears are interconnected by pinion gears, which allow one wheel to slow down or speed up as required. TrueTrac gears have spiral teeth and the pinions are mounted in pockets in the case.

Truetrac differentials are unique in that they increase traction but do not affect steering or wear out prematurely; these problems are common with limited-slip differentials that use clutch plates and springs. A TrueTrac performs like a conventional (open) differential, until there is a loss of traction.

The one in my 2010 Chevy Camaro SS manual coupe, came with a super noisy rear diff at around ~19k miles, despite me changing the gear oil and seeing that it appeared to be decently clean and barely having metallic particles. Maybe the prior owner did the rear diff gear oil change and didn’t use the right weight of gear oil, or maybe forgot to get a formula that included limited slip additive? Cold starts when I first got the car, would have my car turning more than a 1/4 way, to start groaning and clunking. It scared me so much, I’m an idiot for even getting the car. I did my first gear oil change (simple drain and fill) with a semi-synthetic (?) Lucas GL-5 80w-90 gear oil. It supposedly contained “additives”, but nothing that suggested LIMITED SLIP specific additives. It probably meant friction modifiers or some other stuff. Either way, it surprisingly cleared up most of the noise, but was still groaning half as bad during cold starts. The diff would be fine and quiet after reaching optimal temps, which it didn’t before, which also prompted me to believe that someone may have also used a super heavy weight, such as 75w-140. But weren’t these things able to warm up decently? On the dealership test drive, I drove on the freeway for a solid 15-20 minutes, and was also doing a lot of turns and full steering locks around the dealership area during the test drive. Regardless, I stuck to 75w-90 gear oil, but decided to go for a Mobil1 semi-synthetic(?) GL-5 gear oil that contained LS additive already added(‘High Performance’ was the model of the gear oil, I believe). This was my 2nd gear oil change since getting the car and I still didn’t see much metal particles on the magnetic drain and fill plugs for the rear axle differential, but flushing the gear oil probably helped some, as it got to maybe 30-35% as loud as when I got the car. I finally decided to flush it for the final time until this day, which I used the infamous Royal Purple Max Gear 75w-90 that everyone in the Camaro5 community recommends. It comes with LS additive, as well as being a ‘Synchromesh’ specific GL-4+ (GL-4/5) rating, which was safe for yellow metals, such as brass (used for most gearbox synchronizers). Now, this finally got the rear diff to shut up and stay quiet up to a good 10-15% as loud as when I first got the car. However, really cold days (50 F or lower), will have the rear diff groaning just a bit longer (takes longer to warm up probably), but not any more louder! I’m pretty okay now, and dodged a bullet with trying to hassle Chevy to go through the process of trying to work with my rear diff issues, which they did NOT try to address AT ALL whatsoever (that’s a WHOLE other crock of beans…). I may or may not actually try some of the OEM AC Delco gear oil and separate LS additive formula, to see how well it stands up to the aftermarket support products. But as of right now, I don’t plan on adding EXTRA LS additive, like most ppl do to quiet their diffs down, bc I fear of adding too much and having excessive slip that might cause ‘one-wheelers’ with literal straight line driving!!

I have one in a 2007 Mustang GT with a Roush supercharger and 5 speed. Killed the plate posi 1000 miles after installing the supercharger. TrueTrac is the way to go for street use.

Hello Summit i have this Exact one in my 85 chevy Caprice and its been in my car for 2 yrs now and it works really well. i have 3:73 gears also Love it

The machined openings in the case are what positions the gears in place and the gears then free float in this opening.

@MudBarf I think, basically, that the pinion gears get "locked" in their cups in the carrier, until in a turn the outside wheel over-runs the inner, causing its associated pinion gears to become unloaded and allowed to turn. Probably I'm wrong, but it seems similar to a standard open differential except that under load both axles are locked together unless in a turn.

It can handle a lot of horse power you can actually use it on your 1/4 mile racer, it will plant your tires just like a posi.

Holy shit this video's music reminds me of the aircraft selection screens from Ace Combat!

@alcram Thanks, that's interesting. Did you have a lot of traction problems with these units. Theoretically, you should be able to take one drive wheel off the vehicle and support the axle on a wheeled dolly and the remaining drive wheel should push you down the road.

Hi Vinman, This should actually be listed as Eaton Detroit TrueTrac Differential. Detroit is owned by Eaton.

Eaton Truetrac are similar in design to the Gleason Torsen(R), only the Truetrac hold up well with reasonably tall tires.

Great diffs these. I was kinda sad when it rolled away at the end.

Hi Carledward1968, Thank you for sharing your experience with this product! We appreciate your input!

Very good animation.

13 dec 2023 10:19 pm est ( utc - 5 ) : thanks , just-now i finish seeing this movie .

Yes, that is correct!

This is a *TORSEN DIFFERENTIAL*. They're basically an *OPEN DIFF* when one wheel has 0% traction (off the ground, slipping on ice, or doing a "burnout" with one tire), so they aren't all that good for OFFROAD or RACING (because you'll lose power to BOTH wheels if one completely slips), but they're awesome for bigger vehicles that know you'll always have SOME grip at least. *Plus they're smooth, bulletproof, and quiet.*

I have this unit on my 4X4 F150 and on the really rough stuff I have to apply a little brake to get it to work correctly. I am not sure if I would go with this unit again. I may go with the ARB

gasripper2 sounds like a Ford problem I get 2 tires spinning even if I have one in the air 99.9% of the time I've had one spin a couple times but a little more throttle or stopping and starting again kicked the other one in. I'd have to say they are pretty strong. In my 98 k1500 I blew up 2 factory differentials so I decided to try the trutrac I liked the idea of no clutches or springs and no center pin to break. About 100k miles sense install not one problem and sense then the truck has seen allot of upgrades. Vortec 454 swap 5 speed manual swap and I abuse the hell out of the thing without a single complaint.

Ok, this is really bothering me. I've watched this 3 times. I understand the gear meshes, I understand how it allows differentiation through the gear movement, and I even understand (pretty sure) what they're trying to explain with the force diagram. What I still don't understand is how any of that gear meshing provides any resistance to the differentiation process. Is it basically by utilizing the friction created by jamming the pinion gears into the side of the pockets? (Fc) in the diagram?

@kingkruel123 Actual opposite rotation wouldn't happen in a car, the video is exagerated. This diff won't allow the 2 wheels to rotate at different rates without both of them having traction with the ground. If one wheel loses traction, the slipping wheel will rotate at the same rate as the wheel w/ traction because w/ out traction, it can't rotate its worm gear to let the worm wheel rotate, thereby keeping both axles "locked".

are these units going to perform as well for initial straight line grip as a conventional cone type lsd? (i understand neither will outperform a locker), or will it send the torque to the drive wheel and then bias once it loses traction? also with the friction created from the pinion gears while unit is 'locked', generate excess heat?

@AlvinAZ I had the wrong gear oil in it. I had synthetic and I went to the organic stuff and it works fine now!!!

Oh...I think i thought about it backwards... Instead of thinking about it from the perspective of the tire that slips, if you look at it from the perspective of the tire with traction: The traction wheel applies resistance to the slip wheel to make it refrain from spinning..that is to say the system as a whole attempts to keep the slipping wheel going the same speed as the traction wheel...that makes a lot more sense...but I feel like you're losing drivetrain power in the resistance force.

Best animation about TrueTrac. It will be great if you add real demonstration on some car.

This is simply awesome.

If one wheel begins to lose traction , the pinions separate slightly from the side gear and wedge in the pockets. As torque increases, the separating force increases, thus slowing or stopping the spin-out. This allows torque to be distributed to the wheel with the best traction.

Is this the same thing as the S-Trac Differential 35 Spline (Part # N1882) from Strange Engineering?

What is the parts number for the 915a450 pinion gears mine are shattered and just need new pinions

can I install it in any vehicle? like off roaders, SUVs... sport cars?

So basically if you’re going straight it acts like having lockers and when turning it won’t make that’s noise or skip the wheel ?

¿este sirve para suzuki sj 413?

These are GREAT in front diffs...

this is torsen diferential in other configuration

I had one in my 10 bolt silverado with 35 inches tires, i Split the case in two pretty easy....im going with a full locker detroit now

Looks like more pitching is needed in order to prevent a wheel gear from driving a worm gear.

those are bolts?

It is magic! How does it know? How?

Would be grateful with an Elocker function like the tru lock from Jeep Rubicon

video is gooooooooooood but u could have explained its working............

Do you have to time the gears för this type of unit. I have seen the other type (torsen--1 or A) where the gears have markings and installs in a specific way. If yes on timing torsen type 2. Could you explain why, cause I can't see how it would make a difference :)

are the 31 spline versions four helical gear or do they all have six?

Is this designed to work trough continuous track day usage trough years? Also, it's the exact same principle as Quaife Helical ATBs right? Any major differences?

that's it?

so basiclly it kicks in when there is wheel slippage do these true trac last a long time?

Классный диф. Поставил себе в задний мост на Trailblazer. Доволен как слон :-)

holy shoot that's a lot of gears

does using a differential of this design eliminate the need for c clips?

Why isn’t there one for a 2nd gen Colorado?

so basically this differential delivers power to the wheel that has the MOST traction?

Why are they so much more expensive on the 14 bolt 9.5 axle?

So, where does the drive shaft connect?

Love the music....is it Tangerine Dream?,

The music reminds me of Aleksey Zakharov's music for X series space sims

Music from Stunt GP!!!

It's more compact and less resistant friction than Torsen.

this is intresting where did you get the music

so the side gears jam the pinion gears into the pockets and the friction of the pinion gears cutting into the case make this thing work.. this thing would wear out pretty fast

How good are these for 4x4 trucks?

I have this unit on my F150 and when I get into some steep stuff only the wheel with the lightest load spins. I have tried applying some brake but it does nothing. I am not really happy with this unit.

I have a Detroit truetrac and I’m having a clunking sound from starting off till like 10 mph and a loud roar while accelerating until I left off. I was wondering if there is a rebuild kit for the locker it self

Man 13 years ago this video was made .. I’ve been living under a rock… How does it know if it’s on sand , mud , gravel , etc ???

About what kind of horsepower can the True Trac take?

Awesome design Summit! It's essentially a Torsen-type differential but arranged to be more bulletproof right? Having those worm wheel's horizontal probably gets more surface area strength.

it can fit to hilux 2wd varian? I have plan to install rear differencial

Can this handle towing and if so, to what capacity?

So how does this get any posi action? By cranking the planets into the housing walls? Seems like it's going to rip itself up quick. It's an open diff as far as I can tell unless the friction of the planets into the housing is enough to stop them from turning.

is this locker puting in a front differential and is it worth buying for hardcore off roading how about if your going up a hill or in the mud and turning the front wheels would it still have a both tires spining at the same time ???

I know entirely that im nitpicking, but shouldnt the answer be more concerned with torque, than power? 400 hp from an na v8 is a different ball game than 400 hp from a turbo charged diesel engine. Just saying. Great product, LOVE this video. Its fascinating to see whats actually going on inside.

Excelente

importsstillsuck, Anymore power than that; you should consider a Detroit locker differential.

is this a torque sensing version?

the Nismo Wavetrac and True Track are much alike, but the Nismo Wavetrac has 12 pinion gears while the True Track has only 6, it seems to me that the Wavetrac would be much stronger

What software do they used to make this animation???

I just had one installed and it’s doing a lot of clicking on hard turns. Do ya think something may be wrong with the unit or the gear setup? I also just put a cheap STP 80-90 gear oil for the break in, should I put something different?

does anyone know where to get this type or style of diff for a 1987 Suzuki samurai (sj413) . I can't find any models for a samurai on the eaton website, and I hear rumors about the Russian made ones but I only see listings for like new trackers and vitaras, I found a brazil made torsen diff but the website doesn't work right and I can't see how to buy one, or anything.