You can enter your VIN into this Toyota website and see what equipment it had when new: Vehicle Specification | Toyota Owners

I don't think any models had standard rear lockers. But I could be wrong. I know they're more common on Limited models, but still far from common. And pretty rare on SR5 models.

My '99 is a factory manual locker, and it came with the #RARE 4.10 locker diff in the rear. Manual transmissions only came on 'lesser' models (mine is a Highlander package SR5), and lockers were a bit more rare on lesser models as well (where people were presumably watching that total price and not just checking option boxes with abandon), so it's a combination of two rare options on the same car.

My diff started making a whirring noise at around 215K miles, and armed with 'enough knowledge to be dangerous' I found another locking diff and swapped it in, since it was from the far more common automatic lockers, it was a 4.30. And I just assumed (bad idea) that since 'all lockers are 4.30' that mine was a 4.30 as well. Well... apparently 98% of all lockers are 4.30.

Anyhow, I did drive it for a couple of months with the 4.10 in front and the 4.30 in rear. And it really wasn't as bad as you'd think. It's a pretty small difference, and since mine is the SR5/manual trans, it doesn't have the AWD mode - so the only time you use 4WD is in a low traction situation, where the small difference in gearing wasn't enough to make an issue or make it obvious something was off. I did certainly get a bit more tire squawking than normal out in Utah going over bits of sandstone between the sand (like at Elephant Hill) - but barely any more than my wife's manual '96 was doing -with matching diffs. And I'd almost want to say that in some situations it actually worked BETTER - when turning tightly in 4WD the front wheels tend to push wide a bit - but having them turning slightly faster than the rears meant that it would more readily turn in in slippery conditions.

Still, I did notice that I could *never* get it back into 2WD without backing up (just a foot or so), going forward in an S pattern didn't do it. So I eventually put it in 4WD, jacked up one side, and rotated the wheels around and around... and saw them going out of 'synch'. D'oh! Got a 4.30 front diff, swapped that in, it all matches now.

Funny thing is that you could have gotten the easy-to-find Pre-Runner Tacoma locker that is 4.10.

-Charlie

Good to know. You almost never see Taco's in the PnP junkyards, though. 3rd gens are starting to show up though. You have to be fast on the draw though, but I was lucky and nabbed the 4.30 locker diff I'm using now for about $50.

but usually the diff is one of the first things to go, especially a locker. If it's been in the yard for a whole day, it's probably already gone. People know they can sell them on eBay for $$$.

I never said cheap - just easy to find!

-Charlie