Beeping in low range?

Hey there! I'm new to the forum. I just picked up a 2003 Limited V8 4x4. I had a 1995 SR5 V6 for 17 years and loved it, until the motor died. I missed it ever since. So to the question....when I put my rig in low range I get a beeping. It feels like it's in low range. What's the beep mean?

 

If it's beeping it is not in low, thats the vehicle telling you that you did it wrong.
once in 4hi come to a stop, put the transmission into neutral, shift into 4 low (you should hear a click or slight 'thump'), after it has locked into low then reselect your appropriate forward or reverse on the transmission and you should not hear the beeping.
To get out of low, once again come to a stop, put the transmission in neutral (should click/'thump' again) and then once again put the vehicle in gear and you'll be back in 4hi

 

And also welcome to the forum, the 4th gen's are great rigs.