Question Which LSD is the best for stock 02 4WD?

[jchild85]

I would like to install an LSD in the rear end of my 02 Tundra 4WD. Whats the best LSD for this? The truck is all stock, except the tires and wheels. I just want some extra traction for getting to the fishing holes and stuff. No serious offroading. Any input would be appreciated.

Thanks a lot,
Jason C.

[TundraSkyline]

You might want to research whether you want an LSD or a locker.
Most LSDs will "lockup" the differential under acceleration, thats like making a right turn from a stop, so you'll see a noticeable increase in tire wear.
With a locking differential when you need the traction it's there, when you want an open diff, you have one.

[jchild85]

How does the locker work? Do you turn it on and off manually? What locker do you think would fit my application the best?

Thanks for your help,
Jason C

[1of1]

This has got to be a FAQ, but the above poster has it backwards. For your use, it sounds like you want a LSD. It's best for mostly street use and low-traction dirt roads.

There are basically 4 types of differential:
1) Open - if either wheel loses traction, the truck isn't going anywhere
2) Limited Slip - also known as a "posi", as long as both wheels have some traction, they will both be turning. Won't help if you get a wheel in the air, but excellent for loose dirt. Best option for snow too. This is what TRD Tundra's can have from the factory.
3) Locker - Lockright, Detroit, etc. Open normally, but if one wheel loses traction, it locks both together. Best for hard-core offroading. Most of them you can feel engage/disengage while turning (tire chirp and a clunk). For a daily-driver truck, not the best option.
4) Selectable - ARB, OX, works like an open diff normally, but when you turn it on, it locks the wheels together. works great, but expensive and you need to run air lines, compressor, etc.

I would say you should order this LSD TRD LSD Kazuma Limited Slip Differential and expect to pay a few hundred to get it installed.

[jchild85]

Thanks for the info man. I never thought to check the FAQ. I guess I should look before I ask lol. Anyway, thanks again.

[William1]

Originally Posted by 1of1

2) Limited Slip - also known as a "posi"

3) Locker - Lockright, Detroit, etc. Open normally, but if one wheel loses traction, it locks both together.

I would say you should order this LSD TRD LSD Kazuma Limited Slip Differential and expect to pay a few hundred to get it installed.

First off, just to clarify for the sake of avoiding a common misconception about limited slip differentials, the term "posi" is a slang term derived from the brand name Positraction, which was a clutch type limited slip used in GM vehicles. Not every limited slip is Positraction. There are other brands, such as the Ford Traction Lock, Dana Trac Loc, etc.

I prefer not to use the term "posi" to refer to all limited slip differentials, especially since not all are the same type as the original Positraction. There are the geardriven types (Gleason Torsen, Detroit Truetrac, Quaife). Then there is at least one different type of clutch type limited slips, such as those that use cone type clutches (Auburn) instead of multiplate clutches like Positraction uses. Then there is at least one wheel speed sensitive type used in Chevy and GMC trucks. It is a clutch ype limited slip that has internal fly weights that use centrufugal force to lock the clutches, and is commonly referred to as the GovLoc, since it was originally made for military use.

I've known of people over the years that would say things about a Ford, Dodge, etc. having a factory installed Positraction or "posi" when they actually didn't. They had Traction Lock or Sure Grip (or whatever they call it).

I've even had a guy tell me about a guy with a Ford, saying it had factory installed Positraction, and he is convinced that Positraction is a locker. Nothing I said would convince him that it was neither factory Positraction nor a factory locker, or that Positraction is a brand of limited slip and not a locker.

I remember growing up thinking a vehicle equipped with a "posi" was capable of doing amazing feats, by going anywhere. That seemed to be a general misconception. Now that I am older, I know better.

So that's the reasons I avoid using "posi" as a slang term. It helps to avoid confusion and misconceptions.

It's only been within the past 3 or 4 years that the Eaton Corporation has made Positraction as an aftermarket differential for other than GM vehicles, since they now own the trademark.

Another thing: The automatic lockers you listed, such as the Detroit, Lock Right, etc., are NOT open until they automatically lock. Open differentiation means that one wheel rotates faster than the ring gear, while the other rotates slower than the ring gear. And assuming the tire diameters are exactly the same, the difference in speed between each tire and the ring gear are exactly the same.

Here is how automatic lockers differentiate: The locker is in 2 halves. One half connects the carrier to the wheel on one side, the other half connects the carrier to the wheel on the other side. In a turn, the locker half connected to the INSIDE wheel remains locked, while the locker half connected to the outside wheel disengages and ratchets or separates, allowing a difference in wheel speed.

So what is happening during a turn or curve is that the INSIDE wheel is rotating the same speed as the ring gear, while the OUTSIDE wheel is rotating faster than the ring gear.

This is why automatic lockers affect handling like they do when used in a rear axle. If you apply throttle, the INSIDE wheel will try to push the vehicle to the OUTSIDE of the turn. If you lift the throttle, the INSIDE wheel will try to pull the vehicle to the INSIDE of the turn.

And if you apply enough throttle while in a turn or curve, the inside wheel will lose taction and spin faster until it catches up with the speed of the outside wheel.

So in order to corner normally, you have to maintain just enough throttle to maintain your speed, or in the case of a manual transmission, you can push in the clutch and coast.

It sounds like the limited slip you supplied the link to is a good deal as far as limited slips are concerned. If I understand correctly, it's an Eaton Positraction made for Toyota, and it is modified with stronger springs that give more preload for the clutches. This helps give better clutch lockup, although the clutch discs will wear faster. But it shouldn't be too hard for you to learn how to replace the clutches.

If you don't plan on doing any kind of off roading where a locker is needed, that may be your best bet.