After getting stuck on a small MOUND over the weekend in "value edition" T4R, I'm on the hunt for a locker asap.

Been doing a bit of searching on Google and I'm getting conflicting results as usual. Some say that the 4 cylider 2WD manual can have a 7.5" diff in the back, same as the front unit on 4WD models. Others say that ALL 3rd gen 4Runners have 8" units in the rear regardless of year/engine/drivetrain. Anyone that has a similar model and has installed a locker, can you confirm the rear diff size for me?

Being a value edition bucket, I'm looking spend no more than $300, so that leaves me with few options. Either a new Aussie, Powertrax or a used Eaton/Detroit. Any particulate favorites with T4R people?

The truck is used 95% on road with occasional camping and fire roads for the other 5%.

Thanks!

Check your VIN plate. If the axle code starts with an F, it's a 7.5" rear diff, it'll start with a G if it's an 8".

Also, you want a Spartan Locker, $250 on Rockauto. Nothing wrong with Aussie or the others, but the Spartan has a stronger crosspin and is generally less expensive. If your budget is $300, don't bother looking at the Detroits and Grizzlies - they're stronger, but even if you find one under $300 you'll have to pay somebody a couple hundred more to install it.

I have used an Aussie and a Lockright (aka powertrax). Both worked about the same. The Lockright had better road manners, but it was also in a much heavier vehicle, so that probably had something to do with it.

Good for you locking up a 2wd camper, something just feels right about that

All 3rd gen (96-02) 4Runners have the 8 inch V6/Turbo diff for the rear. 4 cylinder and 2wd included.

What about an 03 sport edition what type of diff does it have.

03-09's also use the 8 inch V6 for the rear but they use a 8 inch clamshell for the front instead of the 7.5 inch clamshell that the 3rd gens use.

Sorry my is a 8cyl 2wd. Do you know is it a positive traction or not

Doesn't matter. You still have the 8 inch V6 diff. None of them ever came with Posi or an LSD either.

Thanks buddy. Do you know anyone ever added a locker to 2wd

thanks for the reply, exact info I was looking for.

Two questions tho;

1, why is the eaton locker any more difficult to install than the spartan?
2, I looked at the spartan and some member are having issues with clicking noise (see video Spartan Locker Road Sounds 97' 4runner - YouTube), is this normal?

Those are short questions with kinda long answers.

The Spartan/Aussie/Lockright are all iterations on a basic design that replaces the spider gears inside the differential carrier. Because you don't have to redo your ring and pinion lash, they're called "drop-in" lockers and a driveway mechanic can install them with basic tools. The stronger automatic lockers (Detroit, Grizzly) and the selectable lockers (Eaton, ARB, Toyota elocker) all replace the actual carrier itself - they're much stronger, but installing them means taking apart the entire differential and putting it back together around the locker. That requires some specialized tools and skills, and getting a differential set up right is an art. Check out gearinstalls.com for way way way more photos of the process than you could ever want.

Any automatic locker is going to click. They are designed to let the differential act like a differential when under very light throttle conditions, but lock up when they sense torque from higher throttle. The clicking people hear is the two sides of the locker ratcheting and letting one wheel turn faster than the other. How loud that clicking is depends on a lot of things including which locker you have, what truck it's in, what fluid you have in the diff and how fresh it is, etc., but it's not a Bad Thing. It's just the locker doing what it was designed to do. A bigger issue than the clicking, IMO, is driveline binding caused when the locker engages during a turn, and that can cause tire chirp, wheel hop, and sometimes a bang that'll scare the crap out of you if the locker can't decide whether to lock up or ratchet freely and decides to do both at the same time.

Opinion time - different brands of lockers appear to lock up at different torque levels, and they will definitely behave differently in different trucks, or for different driving styles. In general, an automatic locker will behave better in a truck with less power, more weight, longer wheelbase, and an automatic transmission. I think most of the bad press against automatic lockers comes from Jeep Wrangler guys with super-short wheelbases, and guys with overpowered hick-up trucks and bro-dozers who can't stay off the throttle. As long as you don't drive like a maniac, I don't think you'll have any trouble with any of the automatic lockers in the back of your truck, and the traction benefits once you get in the dirt are undeniable.

^^^ What he said. The clicking is normal, and you can usually quiet it down a bit by running a heavier gear oil in the diff. There are some quirks to driving a truck with an auto locker, but it's really no big deal. I have daily driven 2 trucks with auto lockers in the rear and had no issues whatsoever (aside from explaining to people what the clicking noise is, lol).

Another thing, while an ARB, detroit, or the like is generally considered "stronger" than an auto locker, I can say with 100% certainty that you will not break any decent locker (Aussie, spartan, Lockright, etc) in a 4-banger with sub-35" tires.