What things should I consider when looking for a 2005 or newer Tacoma? Which model has the locking rear differential stock? I will be looking for a double cab, 4x4 model when I sell my Tundra. What differential gears are offered in the Tacoma?

The TRD off road has the rear locker. I believe it also has 3.73 gears.

4x4 double cab

well i would make sure the TSB was done on rear springs !!!!!!

( first hint it wasn't= look at the bumpstops)
i THINK it shows 4 leafs and not 3, but not sure

if over 36k miles it would not be qualify to have it done

To add a little more clarification to what was said above...

On the rear leaf spring TSB, just check to see if it has 4 leafs (stock U.S. vehicles only came with 3 while Canadians got the 4 leaf pack from the factory).

And 2005 - 2008 TRD Off-Road has a mechanical locker in the rear. Beginning in 2009, it came with an e-locker instead of a mechanical one.

And 2005 - 2008 TRD Off-Road has a mechanical locker in the rear. Beginning in 2009, it came with an e-locker instead of a mechanical one.
No sir, my 2007 TRD Off Road has an E-locker in the rear.

^^ Yes and no. 2005 - 2008 O/R use an electronically controlled mechanical locker.

Beginning in 2009, it changed and I am not clear exactly what it is.... I believe it's an auto-LSD (electronic limited slip) system which works with the truck's ABS. Others will correct me and clarify this....

And yes, DC 4x4s come with 3.73 gears.

I believe that the 2009+ TRD Off Road package still has the electronically controlled mechanical locker, the difference is that in 2009 they added ATRAC system which is the ABS linked system that tries to control wheel slippage. The mechanical locker is still available with the OR package. Of course I could be wrong as I have not looked at the rear diff on a 2009+ TRD OR Tacoma but a picture of the front side of the rear axle will confirm. (or I could stop at the dealer and crawl under one-I'm not that dedicated though. :):))