I've just purchase an '04 Tacoma TRD and have questions about the locking rear differential. Do all of these models come with this feature or is it standard for the TRD model? Does the differential lock automatically or is there something I need to do manually? When putting this truck in 4X4 mode can I do it on the fly? Or do I need to stop, put it in 4H, back up, pull forward...etc...that whole routine? Or can I just stop and slam it in gear and go about my way? Just want to be sure before I take it out for it's first off road test in VT next weekend. Thanks All!

 

Going from 2H to 4H you should be able to do while moving.
Going from 4H to 4L I would recommend stopping as the transfer as is changing gear ratios.
There should be a button in the cab for the locker. On my moms 98 tacoma the button is to the left of the steering wheel.
If I remember correctly you will have to be in low range and driving under 5mph for it to engage. There are write ups on here to bypass this so that it will turn on and off by just pushing the button.