Do a 1996 -2001 toyota tacoma rear diff will fit a 2003 tacoma

Yes.

There are 2 diffs.....one with the trd locker, and one without. These 2 diffs are NOT interchangeable.

The electric locker is basically an 8" like all the older axles, with 30 spline axleshafts, but a 4 pinion carrier and odd 3rd member bolt pattern with a notch to clear the locker actuator.

The non-trd Tacomas have a 8.875" axle in which most the components are bigger, from the housing and ring gear to the third member bolts. I *think* all the 8.875" thirds are interchangeable. The spline count is still 30 spline, and the flange on mine was the same (swapped to a TRD housing, kept my stock axles/brakes-minor fabrication required)

OH, and if you broke your spider gear/side gears, and your ring and pinion are still OK, it is VERY VERY EASY to slip in a "lunchbox" locker like a no slip or a Lockright. I am not a fan of the EZ locker (broke mine on my sami) but there is really no gear setup. Just adjust the backlash to what it was before. The locker will be stronger than the OE stuff. Usually when a Toy diff goes, it's because the drive flange nut was loose, or the spider/sides went. This is why I'm mentioning this. Probably CHEAPER than new parts.

Good info to know guys. My 2004 Taco has the first selectable TRD elocker on it that I've ever had. Bit strange; am a little scared to try it on ice at the moment- only 4 payments so far! <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/zombie.gif" alt="" />

Always use 4x4 and open diffs on ice. Locked diff = guaranteed spin on ice. A locked diff is very beneficial in deep snow, though.

Thanks Jeff, been awhile since I've had to think about it. Selecting the elocker sure has a hefty thump when it engages! 4x4 by itself has done well, esp with a camper on the back late Sept in the high country.

I've got 8 acres to give snow a try once it gets deeper! <img src="/forums/images/graemlins/notooth.gif" alt="" />