Just got a oversand beach pass. I have an 07' Thunder road package. (aka big horn)
20x9 tires quad cab 4.7V8

My elec 4x4 switch says 4hi-lock and 4 lo. Whats the difference. Can anyone give me the low-down on my transmission?
what should I use? Are these trucks good in sand? should I deflate tires?

 

Four low is for off roading during slow situations when you need more power and less speed.

 

4hi up to 88km/h
4low up to 25km/h
give or take
if you read the manual it explains eveything

 

Better air down for the beach, the softer the sand, the more you need to air down...

 

its a good idea to find some soft ground(dirt road or some grass will do fine) about once a month or two and throw it in 4hi to keep things in good operating condition for when you need it. not a long way, just a 100 feet or so. Also try to avoid turning the wheel all the way over when 4wd is engaged, that will help keep the stress as low as possible on the axles. and like marx said the manual has a pretty good instruction on how to use it.

 

4 lo, 25 psi in the tires

You'll be fine.